6bil - Revision history

OCA at 09:44, 23 October 2024

2024-10-23T09:44:53Z

← Older revision		Revision as of 09:44, 23 October 2024
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	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [https://pdbe.org/6bil PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [https://www.ebi.ac.uk/pdbsum/6bil PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [https://pdbe.org/6bil PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [https://www.ebi.ac.uk/pdbsum/6bil PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>
	</table>		</table>
			== Disease ==
			[https://www.uniprot.org/uniprot/DRB1_HUMAN DRB1_HUMAN] Giant cell arteritis;NON RARE IN EUROPE: Rheumatoid arthritis;Narcolepsy type 1;Pediatric multiple sclerosis;Sarcoidosis;Systemic lupus erythematosus;Systemic-onset juvenile idiopathic arthritis;Autoimmune pulmonary alveolar proteinosis;Limited systemic sclerosis;Limited cutaneous systemic sclerosis;Diffuse cutaneous systemic sclerosis;NON RARE IN EUROPE: Multiple sclerosis;Follicular lymphoma;Bullous pemphigoid;NON RARE IN EUROPE: Celiac disease;Narcolepsy type 2. In populations of European descent, allele DRB101:03 is associated with increased susceptibility to Crohn disease and colonic ulcerative colitis. Decreased heterozygosity in individuals with colonic ulcerative colitis suggests that it acts as a recessive risk allele.<ref>PMID:25559196</ref> Disease susceptibility is associated with variants affecting the gene represented in this entry. Alleles DRB104:02, DRB111:01 and DRB112:01 are associated with sarcoidosis. Allele DRB104:02 is significantly associated with specific sarcodosis phenotypes such as eye, parotid and salivary gland involvement.<ref>PMID:14508706</ref> Disease susceptibility is associated with variants affecting the gene represented in this entry. In populations of European descent, allele DRB115:01 has the strongest association with multiple sclerosis among all HLA class II alleles. Additional risk is associated with the strongly linked alleles DRB103:01 and DQB102:01 as well as with allele DRB113:03 (PubMed:21833088). It is postulated that bacterial or viral infection triggers the autoimmune MS. Microbial peptides having low affinity crossreactivity to MBP autoantigen, may stimulate autoreactive T cells via molecular mimicry and initiate the autoimmune inflammation (PubMed:19303388).<ref>PMID:19303388</ref> <ref>PMID:21833088</ref> Allele DRB115:01 is associated with increased susceptibility to Goodpasture syndrome. Can present a self-peptide derived from COL4A3 (GWISLWKGFSF) on TCR (TRAV19 biased) in pathogenic CD4-positive T-helper 1 and T-helper 17 cells, triggering autoimmune inflammation.<ref>PMID:28467828</ref> Disease susceptibility is associated with variants affecting the gene represented in this entry. Alleles DRB104:01; DRB104:04; DRB104:05; DRB104:08; DRB110:01; DRB101:01 and DRB1*01:02 are associated with increased susceptibility to rheumatoid arthritis, where affected individuals have antibodies to cyclic citrullinated peptide (anti-CCP-positive rheumatoid arthritis). Variations at position 40 in the peptide-binding cleft of these alleles explain most of the association to rheumatoid arthritis risk.<ref>PMID:22286218</ref>
	== Function ==		== Function ==
	[https://www.uniprot.org/uniprot/~~DRA_HUMAN DRA_HUMAN~~] ~~Binds~~ peptides ~~derived from antigens that access the endocytic route of~~ antigen presenting cells (~~APC~~) ~~and presents them on the cell surface~~ for recognition by ~~the~~ CD4 T-cells. ~~The~~ peptide ~~binding cleft accommodates peptides~~ of 10-30 ~~residues~~. ~~The~~ peptides ~~presented by MHC class II molecules~~ are generated ~~mostly by degradation~~ of proteins that ~~access~~ the ~~endocytic route~~, ~~where they are processed by lysosomal proteases~~ and ~~other hydrolases~~. ~~Exogenous antigens that have been endocytosed by~~ the ~~APC are thus readily available~~ for ~~presentation via MHC II~~ molecules, and for ~~this reason this antigen presentation pathway is usually referred~~ to ~~as exogenous~~. ~~As membrane~~ proteins ~~on their way to degradation in lysosomes as part of their normal turn~~-~~over are also contained in~~ the ~~endosomal/lysosomal compartments~~, ~~exogenous antigens must compete with those~~ derived from ~~endogenous components~~. ~~Autophagy is also a source of endogenous~~ peptides, ~~autophagosomes constitutively fuse~~ with ~~MHC class II loading compartments~~. ~~In addition~~ to ~~APCs~~, ~~other~~ cells of ~~the gastrointestinal tract~~, such as ~~epithelial~~ cells, ~~express MHC class II molecules~~ and ~~CD74~~ and ~~act as APCs~~, ~~which is~~ an ~~unusual trait~~ of ~~the GI tract~~. ~~To produce a MHC class II molecule that~~ presents an antigen, ~~three MHC class II molecules~~ (~~heterodimers of an alpha~~ and ~~a beta chain~~) ~~associate with a CD74 trimer in the ER~~ to ~~form a heterononamer~~. ~~Soon after~~ the ~~entry~~ of ~~this complex into the endosomal/lysosomal system where~~ antigen ~~processing occurs~~, ~~CD74 undergoes~~ a ~~sequential degradation by various proteases, including CTSS~~ and ~~CTSL~~, ~~leaving~~ a ~~small fragment termed CLIP~~ (~~class~~-II-~~associated invariant chain peptide~~). ~~The removal~~ of ~~CLIP is facilitated by HLA~~-~~DM via direct binding~~ to ~~the alpha~~-~~beta~~-~~CLIP complex so that CLIP is released~~. ~~HLA~~-~~DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound~~. ~~The MHC II molecule bound~~ to a peptide ~~is then transported~~ to ~~the cell membrane surface. In B~~-cells, ~~the interaction between HLA~~-~~DM and MHC class II molecules is regulated~~ by ~~HLA~~-~~DO. Primary dendritic~~ cells (~~DCs~~) ~~also~~ to ~~express HLA~~-~~DO. Lysosomal miroenvironment has been implicated~~ in ~~the regulation~~ of ~~antigen loading into MHC II molecules, increased acidification produces increased proteolysis~~ and ~~efficient peptide loading~~.		[https://www.uniprot.org/uniprot/DRB1_HUMAN DRB1_HUMAN] A beta chain of antigen-presenting major histocompatibility complex class II (MHCII) molecule. In complex with the alpha chain HLA-DRA, displays antigenic peptides on professional antigen presenting cells (APCs) for recognition by alpha-beta T cell receptor (TCR) on HLA-DRB1-restricted CD4-positive T cells. This guides antigen-specific T-helper effector functions, both antibody-mediated immune response and macrophage activation, to ultimately eliminate the infectious agents and transformed cells (PubMed:15265931, PubMed:16148104, PubMed:22327072, PubMed:27591323, PubMed:29884618, PubMed:31495665, PubMed:8642306). Typically presents extracellular peptide antigens of 10 to 30 amino acids that arise from proteolysis of endocytosed antigens in lysosomes (PubMed:8145819). In the tumor microenvironment, presents antigenic peptides that are primarily generated in tumor-resident APCs likely via phagocytosis of apoptotic tumor cells or macropinocytosis of secreted tumor proteins (PubMed:31495665). Presents peptides derived from intracellular proteins that are trapped in autolysosomes after macroautophagy, a mechanism especially relevant for T cell selection in the thymus and central immune tolerance (PubMed:17182262, PubMed:23783831). The selection of the immunodominant epitopes follows two processing modes: 'bind first, cut/trim later' for pathogen-derived antigenic peptides and 'cut first, bind later' for autoantigens/self-peptides (PubMed:25413013). The anchor residue at position 1 of the peptide N-terminus, usually a large hydrophobic residue, is essential for high affinity interaction with MHCII molecules (PubMed:8145819).<ref>PMID:15265931</ref> <ref>PMID:17182262</ref> <ref>PMID:22327072</ref> <ref>PMID:23783831</ref> <ref>PMID:25413013</ref> <ref>PMID:27591323</ref> <ref>PMID:29884618</ref> <ref>PMID:31495665</ref> <ref>PMID:8145819</ref> <ref>PMID:8642306</ref> Allele DRB101:01: Displays an immunodominant epitope derived from Bacillus anthracis pagA/protective antigen, PA (KLPLYISNPNYKVNVYAVT), to both naive and PA-specific memory CD4-positive T cells (PubMed:22327072). Presents immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load (PubMed:29884618). May present to T-helper 1 cells several HRV-16 epitopes derived from capsid proteins VP1 (PRFSLPFLSIASAYYMFYDG) and VP2 (PHQFINLRSNNSATLIVPYV), contributing to viral clearance (PubMed:27591323). Displays commonly recognized peptides derived from IAV external protein HA (PKYVKQNTLKLAT and SNGNFIAPEYAYKIVK) and from internal proteins M, NP and PB1, with M-derived epitope (GLIYNRMGAVTTEV) being the most immunogenic (PubMed:25413013, PubMed:32668259, PubMed:8145819, PubMed:9075930). Presents a self-peptide derived from COL4A3 (GWISLWKGFSF) to TCR (TRAV14 biased) on CD4-positive, FOXP3-positive regulatory T cells and mediates immune tolerance to self (PubMed:28467828). May present peptides derived from oncofetal trophoblast glycoprotein TPBG 5T4, known to be recognized by both T-helper 1 and regulatory T cells (PubMed:31619516). Displays with low affinity a self-peptide derived from MBP (VHFFKNIVTPRTP) (PubMed:9075930).<ref>PMID:22327072</ref> <ref>PMID:25413013</ref> <ref>PMID:27591323</ref> <ref>PMID:28467828</ref> <ref>PMID:29884618</ref> <ref>PMID:31619516</ref> <ref>PMID:32668259</ref> <ref>PMID:8145819</ref> <ref>PMID:9075930</ref> Allele DRB103:01: May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (NEKQPSDDNWLNFDGTLLGN), contributing to viral clearance (PubMed:27591323). Displays self-peptides derived from retinal SAG (NRERRGIALDGKIKHE) and thyroid TG (LSSVVVDPSIRHFDV) (PubMed:25413013). Presents viral epitopes derived from HHV-6B gH/U48 and U85 antigens to polyfunctional CD4-positive T cells with cytotoxic activity implicated in control of HHV-6B infection (PubMed:31020640). Presents several immunogenic epitopes derived from C. tetani neurotoxin tetX, playing a role in immune recognition and long-term protection (PubMed:19830726).<ref>PMID:19830726</ref> <ref>PMID:25413013</ref> <ref>PMID:27591323</ref> <ref>PMID:31020640</ref> Allele DRB104:01: Presents an immunodominant bacterial epitope derived from M. tuberculosis esxB/culture filtrate antigen CFP-10 (EISTNIRQAGVQYSR), eliciting CD4-positive T cell effector functions such as IFNG production and cytotoxic activity (PubMed:15265931). May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (NEKQPSDDNWLNFDGTLLGN), contributing to viral clearance (PubMed:27591323). Presents tumor epitopes derived from melanoma-associated TYR antigen (QNILLSNAPLGPQFP and DYSYLQDSDPDSFQD), triggering CD4-positive T cell effector functions such as GMCSF production (PubMed:8642306). Displays preferentially citrullinated self-peptides derived from VIM (GVYATR/citSSAVR and SAVRAR/citSSVPGVR) and ACAN (VVLLVATEGR/ CitVRVNSAYQDK) (PubMed:24190431). Displays self-peptides derived from COL2A1 (PubMed:9354468).<ref>PMID:15265931</ref> <ref>PMID:24190431</ref> <ref>PMID:27591323</ref> <ref>PMID:8642306</ref> <ref>PMID:9354468</ref> Allele DRB104:02: Displays native or citrullinated self-peptides derived from VIM.<ref>PMID:24190431</ref> Allele DRB104:04: May present to T-helper 1 cells several HRV-16 epitopes derived from capsid proteins VP1 (HIVMQYMYVPPGAPIPTTRN) and VP2 (RGDSTITSQDVANAVVGYGV), contributing to viral clearance (PubMed:27591323). Displays preferentially citrullinated self-peptides derived from VIM (SAVRAR/citSSVPGVR) (PubMed:24190431).<ref>PMID:24190431</ref> <ref>PMID:27591323</ref> Allele DRB104:05: May present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (KRYFKLSHLQMHSRKH), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies.<ref>PMID:19120973</ref> Allele DRB105:01: Presents an immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load.<ref>PMID:29884618</ref> Allele DRB107:01: Upon EBV infection, presents latent antigen EBNA2 peptide (PRSPTVFYNIPPMPLPPSQL) to CD4-positive T cells, driving oligoclonal expansion and selection of a dominant virus-specific memory T cell subset with cytotoxic potential to directly eliminate virus-infected B cells (PubMed:31308093). May present to T-helper 1 cells several HRV-16 epitopes derived from capsid proteins VP1 (PRFSLPFLSIASAYYMFYDG) and VP2 (VPYVNAVPMDSMVRHNNWSL), contributing to viral clearance (PubMed:27591323). In the context of tumor immunesurveillance, may present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (MTEYKLVVVGAVGVGKSALTIQLI), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies (PubMed:22929521). In metastatic epithelial tumors, presents to intratumoral CD4-positive T cells a KRAS neoantigen (MTEYKLVVVGAVGVGKSALTIQLI) carrying G12V hotspot driver mutation and may mediate tumor regression (PubMed:30282837).<ref>PMID:22929521</ref> <ref>PMID:27591323</ref> <ref>PMID:30282837</ref> <ref>PMID:31308093</ref> Allele DRB111:01: Displays an immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load (PubMed:29884618). May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (SDRIIQITRGDSTITSQDVA), contributing to viral clearance (PubMed:27591323). Presents several immunogenic epitopes derived from C. tetani neurotoxin tetX, playing a role in immune recognition and longterm protection (PubMed:19830726). In the context of tumor immunesurveillance, may present tumor-derived neoantigens to CD4-positive T cells and trigger anti-tumor helper functions (PubMed:31495665).<ref>PMID:19830726</ref> <ref>PMID:27591323</ref> <ref>PMID:29884618</ref> <ref>PMID:31495665</ref> Allele DRB113:01: Presents viral epitopes derived from HHV-6B antigens to polyfunctional CD4-positive T cells implicated in control of HHV-6B infection.<ref>PMID:31020640</ref> Allele DRB115:01: May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (SNNSATLIVPYVNAVPMDSM), contributing to viral clearance (PubMed:27591323). Displays a self-peptide derived from MBP (ENPVVHFFKNIVTPR) (PubMed:25413013, PubMed:9782128). May present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (KRYFKLSHLQMHSRKH), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies.<ref>PMID:19120973</ref> <ref>PMID:27591323</ref> <ref>PMID:9782128</ref> Allele DRB115:02: Displays an immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load (PubMed:29884618). May present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (KRYFKLSHLQMHSRKH), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies (PubMed:19120973).<ref>PMID:19120973</ref> <ref>PMID:29884618</ref> (Microbial infection) Acts as a receptor for Epstein-Barr virus on lymphocytes.<ref>PMID:11864610</ref> <ref>PMID:9151859</ref>
	<div style="background-color:#fffaf0;">		<div style="background-color:#fffaf0;">
	== Publication Abstract from PubMed ==		== Publication Abstract from PubMed ==

OCA at 14:42, 4 October 2023

2023-10-04T14:42:01Z

← Older revision		Revision as of 14:42, 4 October 2023
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	<StructureSection load='6bil' size='340' side='right'caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>		<StructureSection load='6bil' size='340' side='right'caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/~~Human Human~~]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6BIL FirstGlance]. <br>		<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6BIL FirstGlance]. <br>
	</td></tr><tr id='~~ligand~~'><td class="sblockLbl"><b>[[~~Ligand~~\|~~Ligands~~:]]</b></td><td class="sblockDat" id="~~ligandDat~~">~~<scene name='pdbligand=NAG:N~~-~~ACETYL-D-GLUCOSAMINE'>NAG</scene>~~</td></tr>		</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models\|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution\|Resolution]] 2.4Å</td></tr>
	<tr id='~~NonStdRes~~'><td class="sblockLbl"><b>[[~~Non-Standard_Residue~~\|~~NonStd Res~~:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene><~~/td></tr>~~		<tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
	~~<tr id~~='~~related'><td class~~=~~"sblockLbl"><b>[[Related_structure\|Related~~:~~]]</b></td><td class="sblockDat"><div style='overflow: auto; max~~-~~height: 3em;~~'>~~[[6bij\|6bij]]~~</~~div></td></tr>~~
	~~<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat"~~>HLA-DRA, HLA-DRA1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), HLA-DRB1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [https://pdbe.org/6bil PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [https://www.ebi.ac.uk/pdbsum/6bil PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [https://pdbe.org/6bil PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [https://www.ebi.ac.uk/pdbsum/6bil PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
	[[https://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[https://www.uniprot.org/uniprot/2B14_HUMAN 2B14_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.		[https://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.
	<div style="background-color:#fffaf0;">		<div style="background-color:#fffaf0;">
	== Publication Abstract from PubMed ==		== Publication Abstract from PubMed ==
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	==See Also==		==See Also==
	*[[MHC 3D structures\|MHC 3D structures]]		*[[MHC 3D structures\|MHC 3D structures]]
			*[[MHC II 3D structures\|MHC II 3D structures]]
	== References ==		== References ==
	<references/>		<references/>
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
	[[Category: ~~Human~~]]		[[Category: Homo sapiens]]
	[[Category: Large Structures]]		[[Category: Large Structures]]
	[[Category: Rossjohn, J]]		[[Category: Rossjohn J]]
	[[Category: Scally~~, S W~~]]		[[Category: Scally SW]]
	[[Category: Ting~~, Y T]]~~		[[Category: Ting YT]]
	~~[[Category: Citrulline]]~~
	~~[[Category: Hla]]~~
	~~[[Category: Immune system]]~~
	~~[[Category: Mhc]]~~
	~~[[Category: Rheumatoid arthritis~~]]

OCA at 11:43, 27 April 2022

2022-04-27T11:43:06Z

← Older revision		Revision as of 11:43, 27 April 2022
Line 1:		Line 1:

	==HLA-DRB1 in complex with citrullinated fibrinogen peptide==		==HLA-DRB1 in complex with citrullinated fibrinogen peptide==
	<StructureSection load='6bil' size='340' side='right' caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>		<StructureSection load='6bil' size='340' side='right'caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure with sequence from [~~http~~://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=6BIL FirstGlance]. <br>		<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6BIL FirstGlance]. <br>
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
	<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue\|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene></td></tr>		<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue\|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene></td></tr>
	<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[6bij\|6bij]]</td></tr>		<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[6bij\|6bij]]</div></td></tr>
	<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">HLA-DRA, HLA-DRA1 ([~~http~~://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), HLA-DRB1 ([~~http~~://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>		<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">HLA-DRA, HLA-DRA1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), HLA-DRB1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [~~http~~://pdbe.org/6bil PDBe], [~~http~~://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [~~http~~://www.ebi.ac.uk/pdbsum/6bil PDBsum], [~~http~~://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [https://pdbe.org/6bil PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [https://www.ebi.ac.uk/pdbsum/6bil PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
	[[~~http~~://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[~~http~~://www.uniprot.org/uniprot/2B14_HUMAN 2B14_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.		[[https://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[https://www.uniprot.org/uniprot/2B14_HUMAN 2B14_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.
	<div style="background-color:#fffaf0;">		<div style="background-color:#fffaf0;">
	== Publication Abstract from PubMed ==		== Publication Abstract from PubMed ==
Line 21:		Line 21:
	</div>		</div>
	<div class="pdbe-citations 6bil" style="background-color:#fffaf0;"></div>		<div class="pdbe-citations 6bil" style="background-color:#fffaf0;"></div>

			==See Also==
			*[[MHC 3D structures\|MHC 3D structures]]
	== References ==		== References ==
	<references/>		<references/>
Line 26:		Line 29:
	</StructureSection>		</StructureSection>
	[[Category: Human]]		[[Category: Human]]
			[[Category: Large Structures]]
	[[Category: Rossjohn, J]]		[[Category: Rossjohn, J]]
	[[Category: Scally, S W]]		[[Category: Scally, S W]]

OCA at 20:55, 24 January 2018

2018-01-24T20:55:20Z

← Older revision		Revision as of 20:55, 24 January 2018
Line 1:		Line 1:

	==~~IMMUNE RECEPTOR~~==		==HLA-DRB1 in complex with citrullinated fibrinogen peptide==
	<StructureSection load='6bil' size='340' side='right' caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>		<StructureSection load='6bil' size='340' side='right' caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6BIL FirstGlance]. <br>		<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6BIL FirstGlance]. <br>
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
	<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue\|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene></td></tr>		<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue\|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene></td></tr>
	<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[6bij\|6bij]]</td></tr>		<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[6bij\|6bij]]</td></tr>
			<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">HLA-DRA, HLA-DRA1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), HLA-DRB1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [http://pdbe.org/6bil PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [http://www.ebi.ac.uk/pdbsum/6bil PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [http://pdbe.org/6bil PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [http://www.ebi.ac.uk/pdbsum/6bil PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
	[[http://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[http://www.uniprot.org/uniprot/2B14_HUMAN 2B14_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.		[[http://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[http://www.uniprot.org/uniprot/2B14_HUMAN 2B14_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.
			<div style="background-color:#fffaf0;">
			== Publication Abstract from PubMed ==
			The HLA-DRB1 locus is strongly associated with rheumatoid arthritis (RA) susceptibility, whereupon citrullinated self-peptides bind to HLA-DR molecules bearing the shared epitope (SE) amino acid motif. However, the differing propensity for citrullinated/non-citrullinated self-peptides to bind given HLA-DR allomorphs remains unclear. Here, we used a fluorescence polarisation assay to determine a hierarchy of binding affinities of 34 self-peptides implicated in RA against three HLA-DRB1 allomorphs (HLA-DRB104:01/04:04/*04:05) each possessing the SE motif. For all three HLA-DRB1 allomorphs, we observed a strong correlation between binding affinity and citrullination at P4 of the bound peptide ligand. A differing hierarchy of peptide-binding affinities across the three HLA-DRB1 allomorphs was attributable to the b-chain polymorphisms that resided outside the SE motif and were consistent with sequences of naturally presented peptide ligands. Structure determination of eight HLA-DR4-self-epitope complexes revealed strict conformational convergence of the P4-Cit and surrounding HLA b-chain residues. Polymorphic residues that form part of the P1 and P9 pockets of the HLA-DR molecules provided a structural basis for the preferential binding of the citrullinated self-peptides to the HLA-DR4 allomorphs. Collectively, we provide a molecular basis for the interplay between citrullination of self-antigens and HLA polymorphisms that shape peptide-HLA-DR4 binding affinities in RA.

			The interplay between citrullination and HLA-DRB1 polymorphism in shaping peptide binding hierarchies in Rheumatoid Arthritis.,Ting YT, Petersen J, Ramarathinam SH, Scally SW, Loh KL, Thomas R, Suri A, Baker DG, Purcell AW, Reid HH, Rossjohn J J Biol Chem. 2018 Jan 9. pii: RA117.001013. doi: 10.1074/jbc.RA117.001013. PMID:29317506<ref>PMID:29317506</ref>

			From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
			</div>
			<div class="pdbe-citations 6bil" style="background-color:#fffaf0;"></div>
			== References ==
			<references/>
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
			[[Category: Human]]
	[[Category: Rossjohn, J]]		[[Category: Rossjohn, J]]
	[[Category: Scally, S W]]		[[Category: Scally, S W]]

OCA at 07:01, 17 January 2018

2018-01-17T07:01:02Z

← Older revision		Revision as of 07:01, 17 January 2018
Line 1:		Line 1:
	~~'''Unreleased structure'''~~

	~~The entry~~ 6bil ~~is ON HOLD until Paper Publication~~		==IMMUNE RECEPTOR==
			<StructureSection load='6bil' size='340' side='right' caption='[[6bil]], [[Resolution\|resolution]] 2.40Å' scene=''>
	~~Authors~~: ~~Ting, Y~~.T.~~, Scally, S~~.W.~~, Rossjohn, J~~.		== Structural highlights ==
			<table><tr><td colspan='2'>[[6bil]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6BIL OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6BIL FirstGlance]. <br>
	~~Description~~: ~~IMMUNE RECEPTOR~~		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
	[[~~Category~~: ~~Unreleased Structures~~]]		<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue\|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIR:CITRULLINE'>CIR</scene></td></tr>
	[[~~Category~~: ~~Scally~~, S.W]]		<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[6bij\|6bij]]</td></tr>
	[[~~Category~~: ~~Ting~~, Y.T]]		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6bil FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6bil OCA], [http://pdbe.org/6bil PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6bil RCSB], [http://www.ebi.ac.uk/pdbsum/6bil PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6bil ProSAT]</span></td></tr>
			</table>
			== Function ==
			[[http://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[http://www.uniprot.org/uniprot/2B14_HUMAN 2B14_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.
			__TOC__
			</StructureSection>
	[[Category: Rossjohn, J]]		[[Category: Rossjohn, J]]
			[[Category: Scally, S W]]
			[[Category: Ting, Y T]]
			[[Category: Citrulline]]
			[[Category: Hla]]
			[[Category: Immune system]]
			[[Category: Mhc]]
			[[Category: Rheumatoid arthritis]]

OCA at 06:33, 22 November 2017

2017-11-22T06:33:25Z

← Older revision		Revision as of 06:33, 22 November 2017
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	'''Unreleased structure'''		'''Unreleased structure'''

	The entry 6bil is ON HOLD		The entry 6bil is ON HOLD until Paper Publication

	Authors: Ting, Y.T., Scally, S.W., Rossjohn, J.		Authors: Ting, Y.T., Scally, S.W., Rossjohn, J.

OCA: Protected "6bil" [edit=sysop:move=sysop]

2017-11-08T06:38:39Z

Protected "6bil" [edit=sysop:move=sysop]

← Older revision	Revision as of 06:38, 8 November 2017
(No difference)

OCA: New page: '''Unreleased structure''' The entry 6bil is ON HOLD Authors: Ting, Y.T., Scally, S.W., Rossjohn, J. Description: IMMUNE RECEPTOR Category: Unreleased Structures [[Category: Scally...

2017-11-08T06:38:38Z

New page: '''Unreleased structure''' The entry 6bil is ON HOLD Authors: Ting, Y.T., Scally, S.W., Rossjohn, J. Description: IMMUNE RECEPTOR Category: Unreleased Structures [[Category: Scally...

New page

'''Unreleased structure'''

The entry 6bil is ON HOLD

Authors: Ting, Y.T., Scally, S.W., Rossjohn, J.

Description: IMMUNE RECEPTOR
[[Category: Unreleased Structures]]
[[Category: Scally, S.W]]
[[Category: Ting, Y.T]]
[[Category: Rossjohn, J]]