View source for 8sos


==Human CD1d presenting sphingomyelin C24:1 in complex with VHH nanobody 1D17==
<StructureSection load='8sos' size='340' side='right'caption='[[8sos]], [[Resolution|resolution]] 2.33&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8sos]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Lama_glama Lama glama]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8SOS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8SOS FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.33&#8491;</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='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8sos FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8sos OCA], [https://pdbe.org/8sos PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8sos RCSB], [https://www.ebi.ac.uk/pdbsum/8sos PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8sos ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CD1D_HUMAN CD1D_HUMAN] Antigen-presenting protein that binds self and non-self glycolipids and presents them to T-cell receptors on natural killer T-cells.<ref>PMID:17475845</ref> [https://www.uniprot.org/uniprot/JUN_HUMAN JUN_HUMAN] Transcription factor that recognizes and binds to the enhancer heptamer motif 5'-TGA[CG]TCA-3'. Promotes activity of NR5A1 when phosphorylated by HIPK3 leading to increased steroidogenic gene expression upon cAMP signaling pathway stimulation.<ref>PMID:10995748</ref> <ref>PMID:17210646</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
BACKGROUND: CD1d is a monomorphic major histocompatibility complex class I-like molecule that presents lipid antigens to distinct T-cell subsets and can be expressed by various malignancies. Antibody-mediated targeting of CD1d on multiple myeloma cells was reported to induce apoptosis and could therefore constitute a novel therapeutic approach. METHODS: To determine how a CD1d-specific single-domain antibody (VHH) enhances binding of the early apoptosis marker annexin V to CD1d(+) tumor cells we use in vitro cell-based assays and CRISPR-Cas9-mediated gene editing, and to determine the structure of the VHH1D17-CD1d(endogenous lipid) complex we use X-ray crystallography. RESULTS: Anti-CD1d VHH1D17 strongly enhances annexin V binding to CD1d(+) tumor cells but this does not reflect induction of apoptosis. Instead, we show that VHH1D17 enhances presentation of phosphatidylserine (PS) in CD1d and that this is saposin dependent. The crystal structure of the VHH1D17-CD1d(endogenous lipid) complex demonstrates that VHH1D17 binds the A'-pocket of CD1d, leaving the lipid headgroup solvent exposed, and has an electro-negatively charged patch which could be involved in the enhanced PS presentation by CD1d. Presentation of PS in CD1d does not trigger phagocytosis but leads to greatly enhanced binding of T-cell immunoglobulin and mucin domain containing molecules (TIM)-1 to TIM-3, TIM-4 and induces TIM-3 signaling. CONCLUSION: Our findings reveal the existence of an immune modulatory CD1d(PS)-TIM axis with potentially unexpected implications for immune regulation in both physiological and pathological conditions.

Enhanced CD1d phosphatidylserine presentation using a single-domain antibody promotes immunomodulatory CD1d-TIM-3 interactions.,Lameris R, Shahine A, Veth M, Westerman B, Godfrey DI, Lutje Hulsik D, Brouwer P, Rossjohn J, de Gruijl TD, van der Vliet HJ J Immunother Cancer. 2023 Dec 1;11(12):e007631. doi: 10.1136/jitc-2023-007631. PMID:38040419<ref>PMID:38040419</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8sos" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Lama glama]]
[[Category: Large Structures]]
[[Category: Rossjohn J]]
[[Category: Shahine A]]