View source for 4z68


==Hybrid structural analysis of the Arp2/3 regulator Arpin identifies its acidic tail as a primary binding epitope==
<StructureSection load='4z68' size='340' side='right'caption='[[4z68]], [[Resolution|resolution]] 1.86&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4z68]] 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=4Z68 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4Z68 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]] 1.859&#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></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=4z68 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4z68 OCA], [https://pdbe.org/4z68 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4z68 RCSB], [https://www.ebi.ac.uk/pdbsum/4z68 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4z68 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ARPIN_HUMAN ARPIN_HUMAN] Regulates actin polymerization by inhibiting the actin-nucleating activity of the Arp2/3 complex; the function is competitive with nucleation promoting factors. Participates in an incoherent feedforward loop at the lamellipodium tip where it inhibits the ARP2/2 complex in response to Rac signaling and where Rac also stimulates actin polymerization through the WAVE complex. Involved in steering cell migration by controlling its directional persistence.<ref>PMID:24132237</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Arpin is a newly discovered regulator of actin polymerization at the cell leading edge, which steers cell migration by exerting a negative control on the Arp2/3 complex. Arpin proteins have an acidic tail homologous to the acidic motif of the VCA domain of nucleation-promoting factors (NPFs). This tail is predicted to compete with the VCA of NPFs for binding to the Arp2/3 complex, thereby mitigating activation and/or tethering of the complex to sites of actin branching. Here, we investigated the structure of full-length Arpin using synchrotron small-angle X-ray scattering, and of its acidic tail in complex with an ankyrin repeats domain using X-ray crystallography. The data were combined in a hybrid model in which the acidic tail extends from the globular core as a linear peptide and forms a primary epitope that is readily accessible in unbound Arpin and suffices to tether Arpin to interacting proteins with high affinity.

Hybrid Structural Analysis of the Arp2/3 Regulator Arpin Identifies Its Acidic Tail as a Primary Binding Epitope.,Fetics S, Thureau A, Campanacci V, Aumont-Nicaise M, Dang I, Gautreau A, Perez J, Cherfils J Structure. 2016 Jan 5. pii: S0969-2126(15)00505-5. doi:, 10.1016/j.str.2015.12.001. PMID:26774128<ref>PMID:26774128</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4z68" style="background-color:#fffaf0;"></div>

==See Also==
*[[Poly(ADP-ribose) polymerase 3D structures|Poly(ADP-ribose) polymerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Campanacci V]]
[[Category: Cherfils J]]
[[Category: Dang I]]
[[Category: Fetics SK]]
[[Category: Gautreau A]]