RGD Reference Report - Biochemical characterization of the high affinity binding between the glycine receptor and gephyrin. - Rat Genome Database

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Biochemical characterization of the high affinity binding between the glycine receptor and gephyrin.

Authors: Schrader, N  Kim, EY  Winking, J  Paulukat, J  Schindelin, H  Schwarz, G 
Citation: Schrader N, etal., J Biol Chem 2004 Apr 30;279(18):18733-41. Epub 2004 Feb 19.
RGD ID: 1300220
Pubmed: (View Article at PubMed) PMID:14976213
DOI: Full-text: DOI:10.1074/jbc.M311245200

Gephyrin is an essential and instructive molecule for the formation of inhibitory synapses. Gephyrin binds directly to the large cytoplasmic loop located between transmembrane helices three and four of the beta-subunit of the glycine receptor and to microtubules, thus promoting glycine receptor (GlyR) anchoring to the cytoskeleton and clustering in the postsynaptic membrane. Besides its structural role, gephyrin is involved in the biosynthesis of the molybdenum cofactor that is essential for all molybdenum-dependent enzymes in mammals. Gephyrin can be divided into an N-terminal trimeric G domain and a C-terminal E domain, which are connected by a central linker region. Here we have studied the in vitro interaction of gephyrin and its domains with the large cytoplasmic loop of the GlyR beta-sub-unit (GlyRbeta-loop). Binding of gephyrin to the GlyR is exclusively mediated by the E domain, and the binding site was mapped to one of its sub-domains (residues 496-654). By using isothermal titration calorimetry, a high affinity (K(d) = 0.2-0.4 microm) and low affinity (K(d) = 11-30 microm) binding site for the GlyRbeta-loop was found on holo-gephyrin and the E domain, respectively, with a binding stoichiometry of two GlyRbeta-loops per E domain in both cases. Binding of the GlyRbeta-loop does not change the oligomeric state of either full-length gephyrin or the isolated E domain.

Gene Ontology Annotations    

Biological Process

Cellular Component

Molecular Function

Molecular Pathway Annotations    
Objects Annotated

Genes (Rattus norvegicus)
Glrb  (glycine receptor, beta)
Gphn  (gephyrin)

Genes (Mus musculus)
Gphn  (gephyrin)

Genes (Homo sapiens)
GPHN  (gephyrin)

Additional Information