Structural highlights
1e42 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Method: | X-ray diffraction, Resolution 1.7Å |
| Ligands: | , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
AP2B1_HUMAN 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 beta subunit acts via its C-terminal appendage domain as a scaffolding platform for endocytic accessory proteins; at least some clathrin-associated sorting proteins (CLASPs) are recognized by their [DE]-X(1,2)-F-X-X-[FL]-X-X-X-R motif. The AP-2 beta subunit binds to clathrin heavy chain, promoting clathrin lattice assembly; clathrin displaces at least some CLASPs from AP2B1 which probably then can be positioned for further coat assembly.[1] [2] [3] [4]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The heterotetrameric AP2 adaptor (alpha, beta 2, mu 2 and sigma 2 subunits) plays a central role in clathrin-mediated endocytosis. We present the protein recruitment function and 1.7 A resolution structure of its beta 2-appendage domain to complement those previously determined for the mu 2 subunit and alpha appendage. Using structure-directed mutagenesis, we demonstrate the ability of the beta 2 appendage alone to bind directly to clathrin and the accessory proteins AP180, epsin and eps15 at the same site. Clathrin polymerization is promoted by binding of clathrin simultaneously to the beta 2-appendage site and to a second site on the adjacent beta 2 hinge. This results in the displacement of the other ligands from the beta 2 appendage. Thus clathrin binding to an AP2-accessory protein complex would cause the controlled release of accessory proteins at sites of vesicle formation.
The structure and function of the beta 2-adaptin appendage domain.,Owen DJ, Vallis Y, Pearse BM, McMahon HT, Evans PR EMBO J. 2000 Aug 15;19(16):4216-27. PMID:10944104[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Nakatsu F, Ohno H. Adaptor protein complexes as the key regulators of protein sorting in the post-Golgi network. Cell Struct Funct. 2003 Oct;28(5):419-29. PMID:14745134
- ↑ Owen DJ, Collins BM, Evans PR. Adaptors for clathrin coats: structure and function. Annu Rev Cell Dev Biol. 2004;20:153-91. PMID:15473838 doi:10.1146/annurev.cellbio.20.010403.104543
- ↑ Huang F, Khvorova A, Marshall W, Sorkin A. Analysis of clathrin-mediated endocytosis of epidermal growth factor receptor by RNA interference. J Biol Chem. 2004 Apr 16;279(16):16657-61. Epub 2004 Feb 25. PMID:14985334 doi:10.1074/jbc.C400046200
- ↑ Lau AW, Chou MM. The adaptor complex AP-2 regulates post-endocytic trafficking through the non-clathrin Arf6-dependent endocytic pathway. J Cell Sci. 2008 Dec 15;121(Pt 24):4008-17. doi: 10.1242/jcs.033522. Epub 2008, Nov 25. PMID:19033387 doi:10.1242/jcs.033522
- ↑ Owen DJ, Vallis Y, Pearse BM, McMahon HT, Evans PR. The structure and function of the beta 2-adaptin appendage domain. EMBO J. 2000 Aug 15;19(16):4216-27. PMID:10944104 doi:10.1093/emboj/19.16.4216
