View source for 9lkm


==Focused map of C1ql1-gC1q trimer and BAI3-eCUB complex==
<StructureSection load='9lkm' size='340' side='right'caption='[[9lkm]], [[Resolution|resolution]] 3.34&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9lkm]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9LKM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9LKM FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.34&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=9lkm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9lkm OCA], [https://pdbe.org/9lkm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9lkm RCSB], [https://www.ebi.ac.uk/pdbsum/9lkm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9lkm ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C1QRF_MOUSE C1QRF_MOUSE] May regulate the number of excitatory synapses that are formed on hippocampus neurons. Has no effect on inhibitory synapses.<ref>PMID:21262840</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cell adhesion molecules (CAMs) are pivotal in establishing and maintaining synaptic connectivity. Emerging evidence indicates that some secreted factors within the synaptic cleft, including C1q-like proteins (C1qls), play a crucial role in bridging pre- and post-synapses by connecting the bilateral CAMs. However, the mechanisms of those secreted factors in synapse assembly remain incomplete. Here, we explore C1ql-mediated synaptic connectivity, focusing on the assembly of C1ql1 and its postsynaptic receptor brain-specific angiogenesis inhibitor 3 (BAI3, also called ADGRB3). Our biochemical, structural, and computational analyses reveal that the trimeric globular C1q (gC1q) domain of C1ql1 undergoes a calcium-modulated domain-swapping event to form a hexamer. Cryo-EM study manifests the stabilizing role of calcium ions on the C1ql1_gC1q hexamer in complex with the extended CUB domain of BAI3. Using the gC1q hexamer, full-length C1ql1 further assembles into linear clusters, possibly providing a scaffold to accumulate BAI3 receptors on the plasma membrane. Our cellular and in vivo studies support a role for the gC1q-mediated dynamic assembly of C1ql1 in receptor accumulation and synapse maintenance. Collectively, our findings provide a plausible mechanism of secreted factor-mediated synaptic connectivity, driven by the calcium-modulated assembly of C1qls and their interactions with CAMs.

Structural basis of calcium-dependent C1ql1/BAI3 assemblies in synaptic connectivity.,Liao L, Han Y, Niu F, Wang Y, Lu Y, Xu S, Zhu H, Lin L, Xiao J, Tou HI, Gao J, Zhang B, Wei Z Nat Commun. 2025 Dec 10. doi: 10.1038/s41467-025-66254-1. PMID:41372137<ref>PMID:41372137</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9lkm" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Liao L]]
[[Category: Niu F]]
[[Category: Wei Z]]