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A single immunoglobulin‐domain protein required for clustering acetylcholine receptors in C. elegans
Author(s) -
Rapti Georgia,
Richmond Janet,
Bessereau JeanLouis
Publication year - 2011
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2010.355
Subject(s) - biology , caenorhabditis elegans , acetylcholine receptor , antibody , receptor , cluster analysis , genetics , computational biology , microbiology and biotechnology , gene , machine learning , computer science
At Caenorhabditis elegans neuromuscular junctions (NMJs), synaptic clustering of the levamisole‐sensitive acetylcholine receptors (L‐AChRs) relies on an extracellular scaffold assembled in the synaptic cleft. It involves the secreted protein LEV‐9 and the ectodomain of the transmembrane protein LEV‐10, which are both expressed by muscle cells. L‐AChRs, LEV‐9 and LEV‐10 are part of a physical complex, which localizes at NMJs, yet none of its components localizes independently at synapses. In a screen for mutants partially resistant to the cholinergic agonist levamisole, we identified oig ‐ 4 , which encodes a small protein containing a single immunoglobulin domain. The OIG‐4 protein is secreted by muscle cells and physically interacts with the L‐AChR/LEV‐9/LEV‐10 complex. Removal of OIG‐4 destabilizes the complex and causes a loss of L‐AChR clusters at the synapse. Interestingly, OIG‐4 partially localizes at NMJs independently of LEV‐9 and LEV‐10, thus providing a potential link between the L‐AChR‐associated scaffold and local synaptic cues. These results add a novel paradigm for the immunoglobulin super‐family as OIG‐4 is a secreted protein required for clustering ionotropic receptors independently of synapse formation.