View source for 1q56


==NMR structure of the B0 isoform of the agrin G3 domain in its Ca2+ bound state==
<StructureSection load='1q56' size='340' side='right'caption='[[1q56]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1q56]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Q56 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1Q56 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=1q56 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1q56 OCA], [https://pdbe.org/1q56 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1q56 RCSB], [https://www.ebi.ac.uk/pdbsum/1q56 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1q56 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AGRIN_CHICK AGRIN_CHICK] Isoform 1: heparan sulfate basal lamina glycoprotein that plays a central role in the formation and the maintenance of the neuromuscular junction (NMJ) and directs key events in postsynaptic differentiation. Component of the AGRN-LRP4 receptor complex that induces the phosphorylation and activation of MUSK. The activation of MUSK in myotubes induces the formation of NMJ by regulating different processes including the transcription of specific genes and the clustering of AChR in the postsynaptic membrane. Calcium ions are required for maximal AChR clustering. AGRN funtion in neurons is highly regulated by alternative splicing, glycan binding and proteolytic processing. Modulates calcium ion homestasis in neurons, specifically by inducing an increase in cytoplasmic calcium ions. Functions differentially in the central nervous system (CNS) by inhibiting the alpha(3)-subtype of Na+/K+-ATPase and evoking depolarization at CNS synapses.<ref>PMID:7860635</ref> <ref>PMID:11425874</ref> <ref>PMID:15198666</ref> <ref>PMID:17012237</ref> <ref>PMID:17649979</ref> <ref>PMID:19940118</ref> <ref>PMID:22984437</ref>   Isoform 9: transmembrane agrin (TM-agrin), the predominant form in neurons of the brain, induces dendritic filopodia and synapse formation in mature hippocampal neurons in large part due to the attached glycosaminoglycan chains and the action of Rho-family GTPases.<ref>PMID:7860635</ref> <ref>PMID:11425874</ref> <ref>PMID:15198666</ref> <ref>PMID:17012237</ref> <ref>PMID:17649979</ref> <ref>PMID:19940118</ref> <ref>PMID:22984437</ref>   Isoform 2, isoform 4 and isoform 7: muscle agrin isoforms, which lack the 8-amino acid insert at the 'B' site, but with the insert at the'A' site have no AChr clustering activity nor MUSK activation but bind heparin. Bind alpha-dystroglycan with lower affinity.<ref>PMID:7860635</ref> <ref>PMID:11425874</ref> <ref>PMID:15198666</ref> <ref>PMID:17012237</ref> <ref>PMID:17649979</ref> <ref>PMID:19940118</ref> <ref>PMID:22984437</ref>   Isoform 5: muscle agrin A0B0 lacking inserts at both 'A' and 'B' sites has no heparin-binding nor AChR clustering activity but binds strongly alpha-dystroglycan.<ref>PMID:7860635</ref> <ref>PMID:11425874</ref> <ref>PMID:15198666</ref> <ref>PMID:17012237</ref> <ref>PMID:17649979</ref> <ref>PMID:19940118</ref> <ref>PMID:22984437</ref>   Agrin N-terminal 110 kDa subunit: is involved in modulation of growth factor signaling (By similarity). Involved also in the regulation of neurite outgrowth probably due to the presence of the glycosaminoglcan (GAG) side chains of heparan and chondroitin sulfate attached to the Ser/Thr- and Gly/Ser-rich regions. Also involved in modulation of growth factor signaling.<ref>PMID:7860635</ref> <ref>PMID:11425874</ref> <ref>PMID:15198666</ref> <ref>PMID:17012237</ref> <ref>PMID:17649979</ref> <ref>PMID:19940118</ref> <ref>PMID:22984437</ref>   Agrin C-terminal 22 kDa fragment: this released fragment is important for agrin signaling and to exert a maximal dendritic filopodia-inducing effect. All 'B' splice variants of this fragment also show an increase in the number of filopodia.<ref>PMID:7860635</ref> <ref>PMID:11425874</ref> <ref>PMID:15198666</ref> <ref>PMID:17012237</ref> <ref>PMID:17649979</ref> <ref>PMID:19940118</ref> <ref>PMID:22984437</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q5/1q56_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1q56 ConSurf].
<div style="clear:both"></div>

==See Also==
*[[Agrin 3D structures|Agrin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Gallus gallus]]
[[Category: Large Structures]]
[[Category: Alexandrescu AT]]
[[Category: Frank S]]
[[Category: Jenny M]]
[[Category: Kammerer RA]]
[[Category: Landwehr R]]
[[Category: Maciejewski MW]]
[[Category: Rathgeb-Szabo K]]
[[Category: Ruegg MA]]
[[Category: Schulthess T]]
[[Category: Stetefeld J]]