View source for 5fpi


==Mu2 adaptin subunit of the AP2 adaptor (C-terminal domain) complexed with Integrin alpha4 internalisation peptide QYKSILQE==
<StructureSection load='5fpi' size='340' side='right'caption='[[5fpi]], [[Resolution|resolution]] 2.77&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5fpi]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5FPI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5FPI 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]] 2.77&#8491;</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=5fpi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5fpi OCA], [https://pdbe.org/5fpi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5fpi RCSB], [https://www.ebi.ac.uk/pdbsum/5fpi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5fpi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AP2M1_RAT AP2M1_RAT] Component of the adaptor protein complex 2 (AP-2). Adaptor protein complexes function in protein transport via transport vesicles in different membrane traffic pathways. Adaptor protein complexes are vesicle coat components and appear to be involved in cargo selection and vesicle formation. AP-2 is involved in clathrin-dependent endocytosis in which cargo proteins are incorporated into vesicles surrounded by clathrin (clathrin-coated vesicles, CCVs) which are destined for fusion with the early endosome. The clathrin lattice serves as a mechanical scaffold but is itself unable to bind directly to membrane components. Clathrin-associated adaptor protein (AP) complexes which can bind directly to both the clathrin lattice and to the lipid and protein components of membranes are considered to be the major clathrin adaptors contributing the CCV formation. AP-2 also serves as a cargo receptor to selectively sort the membrane proteins involved in receptor-mediated endocytosis. AP-2 seems to play a role in the recycling of synaptic vesicle membranes from the presynaptic surface. AP-2 recognizes Y-X-X-[FILMV] (Y-X-X-Phi) and [ED]-X-X-X-L-[LI] endocytosis signal motifs within the cytosolic tails of transmembrane cargo molecules. AP-2 may also play a role in maintaining normal post-endocytic trafficking through the ARF6-regulated, non-clathrin pathway. The AP-2 mu subunit binds to transmembrane cargo proteins; it recognizes the Y-X-X-Phi motifs. The surface region interacting with to the Y-X-X-Phi motif is inaccessible in cytosolic AP-2, but becomes accessible through a conformational change following phosphorylation of AP-2 mu subunit at 'Tyr-156' in membrane-associated AP-2. The membrane-specific phosphorylation event appears to involve assembled clathrin which activates the AP-2 mu kinase AAK1 (By similarity). Plays a role in endocytosis of frizzled family members upon Wnt signaling.<ref>PMID:11516654</ref> <ref>PMID:14745134</ref> <ref>PMID:15473838</ref> <ref>PMID:20947020</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Integrins are heterodimeric cell-surface adhesion molecules comprising one of 18 possible alpha-chains and one of eight possible beta-chains. They control a range of cell functions in a matrix- and ligand-specific manner. Integrins can be internalized by clathrin-mediated endocytosis (CME) through beta subunit-based motifs found in all integrin heterodimers. However, whether specific integrin heterodimers can be selectively endocytosed was unknown. Here, we found that a subset of alpha subunits contain an evolutionarily conserved and functional YxxPhi motif directing integrins to selective internalization by the most abundant endocytic clathrin adaptor, AP2. We determined the structure of the human integrin alpha4-tail motif in complex with the AP2 C-mu2 subunit and confirmed the interaction by isothermal titration calorimetry. Mutagenesis of the motif impaired selective heterodimer endocytosis and attenuated integrin-mediated cell migration. We propose that integrins evolved to enable selective integrin-receptor turnover in response to changing matrix conditions.

Selective integrin endocytosis is driven by interactions between the integrin alpha-chain and AP2.,De Franceschi N, Arjonen A, Elkhatib N, Denessiouk K, Wrobel AG, Wilson TA, Pouwels J, Montagnac G, Owen DJ, Ivaska J Nat Struct Mol Biol. 2016 Jan 18. doi: 10.1038/nsmb.3161. PMID:26779610<ref>PMID:26779610</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5fpi" style="background-color:#fffaf0;"></div>

==See Also==
*[[Adaptin 3D structures|Adaptin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Evans PR]]
[[Category: Ivaska J]]
[[Category: Owen DJ]]