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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alternative Splicing
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Amino Acid Sequence
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Animals
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Base Sequence
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Brain / metabolism*
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Carrier Proteins / metabolism*
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Cell Line
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Conserved Sequence
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GTP Phosphohydrolases / metabolism
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Guanine Nucleotide Exchange Factors / genetics
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Guanine Nucleotide Exchange Factors / physiology*
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Humans
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Macromolecular Substances
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Membrane Proteins / metabolism*
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Molecular Sequence Data
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Organ Specificity
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Protein Isoforms / metabolism
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Protein Isoforms / physiology
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Rats
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Receptors, Glycine / metabolism
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Rho Guanine Nucleotide Exchange Factors
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Sequence Homology, Amino Acid
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Synapses / metabolism
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Synaptic Membranes / metabolism*
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src Homology Domains
Substances
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ARHGEF9 protein, human
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Arhgef9 protein, rat
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Carrier Proteins
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Guanine Nucleotide Exchange Factors
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Macromolecular Substances
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Membrane Proteins
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Protein Isoforms
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Receptors, Glycine
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Rho Guanine Nucleotide Exchange Factors
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gephyrin
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GTP Phosphohydrolases