View source for 4u97


==Crystal Structure of Asymmetric IRAK4 Dimer==
<StructureSection load='4u97' size='340' side='right'caption='[[4u97]], [[Resolution|resolution]] 2.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4u97]] is a 2 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=4U97 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4U97 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]] 2.65&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=STU:STAUROSPORINE'>STU</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=4u97 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4u97 OCA], [https://pdbe.org/4u97 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4u97 RCSB], [https://www.ebi.ac.uk/pdbsum/4u97 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4u97 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/IRAK4_HUMAN IRAK4_HUMAN] Defects in IRAK4 are the cause of recurrent isolated invasive pneumococcal disease type 1 (IPD1) [MIM:[https://omim.org/entry/610799 610799]. Recurrent invasive pneumococcal disease (IPD) is defined as two episodes of IPD occurring at least 1 month apart, whether caused by the same or different serotypes or strains. Recurrent IPD occurs in at least 2% of patients in most series, making IPD the most important known risk factor for subsequent IPD.<ref>PMID:16950813</ref>   Defects in IRAK4 are the cause of IRAK4 deficiency (IRAK4D) [MIM:[https://omim.org/entry/607676 607676]. IRAK4 deficiency causes extracellular pyogenic bacterial and fungal infections in otherwise healthy children.<ref>PMID:12925671</ref> <ref>PMID:12637671</ref> 
== Function ==
[https://www.uniprot.org/uniprot/IRAK4_HUMAN IRAK4_HUMAN] Serine/threonine-protein kinase that plays a critical role in initiating innate immune response against foreign pathogens. Involved in Toll-like receptor (TLR) and IL-1R signaling pathways. Is rapidly recruited by MYD88 to the receptor-signaling complex upon TLR activation to form the Myddosome together with IRAK2. Phosphorylates initially IRAK1, thus stimulating the kinase activity and intensive autophosphorylation of IRAK1. Phosphorylates E3 ubiquitin ligases Pellino proteins (PELI1, PELI2 and PELI3) to promote pellino-mediated polyubiquitination of IRAK1. Then, the ubiquitin-binding domain of IKBKG/NEMO binds to polyubiquitinated IRAK1 bringing together the IRAK1-MAP3K7/TAK1-TRAF6 complex and the NEMO-IKKA-IKKB complex. In turn, MAP3K7/TAK1 activates IKKs (CHUK/IKKA and IKBKB/IKKB) leading to NF-kappa-B nuclear translocation and activation. Alternatively, phosphorylates TIRAP to promote its ubiquitination and subsequent degradation. Phosphorylates NCF1 and regulates NADPH oxidase activation after LPS stimulation suggesting a similar mechanism during microbial infections.<ref>PMID:11960013</ref> <ref>PMID:12538665</ref> <ref>PMID:15084582</ref> <ref>PMID:17217339</ref> <ref>PMID:17337443</ref> <ref>PMID:17997719</ref> <ref>PMID:20400509</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
trans-autophosphorylation is among the most prevalent means of protein kinase activation, yet its molecular basis is poorly defined. In Toll-like receptor and interleukin-1 receptor signaling pathways, the kinase IRAK4 is recruited to the membrane-proximal adaptor MyD88 through death domain (DD) interactions, forming the oligomeric Myddosome and mediating NF-kappaB activation. Here we show that unphosphorylated IRAK4 dimerizes in solution with a KD of 2.5 muM and that Myddosome assembly greatly enhances IRAK4 kinase domain (KD) autophosphorylation at sub-KD concentrations. The crystal structure of the unphosphorylated IRAK4(KD) dimer captures a conformation that appears to represent the actual trans-autophosphorylation reaction, with the activation loop phosphosite of one IRAK4 monomer precisely positioned for phosphotransfer by its partner. We show that dimerization is crucial for IRAK4 autophosphorylation in vitro and ligand-dependent signaling in cells. These studies identify a mechanism for oligomerization-driven allosteric autoactivation of IRAK4 that may be general to other kinases activated by autophosphorylation.

IRAK4 Dimerization and trans-Autophosphorylation Are Induced by Myddosome Assembly.,Ferrao R, Zhou H, Shan Y, Liu Q, Li Q, Shaw DE, Li X, Wu H Mol Cell. 2014 Sep 18;55(6):891-903. doi: 10.1016/j.molcel.2014.08.006. Epub 2014, Sep 4. PMID:25201411<ref>PMID:25201411</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4u97" style="background-color:#fffaf0;"></div>

==See Also==
*[[Interleukin-1 receptor-associated kinase|Interleukin-1 receptor-associated kinase]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Ferrao R]]
[[Category: Wu H]]