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Published on: September 21, 2014
Collybistin, a newly identified brain-specific GEF, induces submembrane clustering of gephyrin
1Department of Neurochemistry, Max-Planck-Institute for Brain Research, Deutschordenstr. 46, D-60528 Frankfurt, Germany.
Abstract:
The formation of postsynaptic GABAA and glycine receptor clusters requires the receptor-associated peripheral membrane protein gephyrin. Here we describe two splice variants of a novel gephyrin-binding protein, termed collybistin I and II, which belong to the family of dbl-like GDP/GTP exchange factors (GEFs). Co-expression of collybistin II with gephyrin induced the formation of submembrane gephyrin aggregates that accumulate hetero-oligomeric glycine receptors. Our data suggest that collybistin II regulates the membrane deposition of gephyrin by activating a GTPase of the Rho/Rac family. Therefore, this protein may be an important determinant of inhibitory postsynaptic membrane formation and plasticity.
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