Structural highlights
Function
[GEPH_RAT] Microtubule-associated protein involved in membrane protein-cytoskeleton interactions. It is thought to anchor the inhibitory glycine receptor (GLYR) to subsynaptic microtubules (By similarity). Catalyzes two steps in the biosynthesis of the molybdenum cofactor. In the first step, molybdopterin is adenylated. Subsequently, molybdate is inserted into adenylated molybdopterin and AMP is released.[1] [2] [GLRB_RAT] The glycine receptor is a neurotransmitter-gated ion channel. Binding of glycine to its receptor increases the chloride conductance and thus produces hyperpolarization (inhibition of neuronal firing).
Publication Abstract from PubMed
Gephyrin is a major determinant for the accumulation and anchoring of glycine receptors (GlyRs) and the majority of gamma-aminobutyric acid type A receptors (GABAARs) at postsynaptic sites. Here we explored the interaction of gephyrin with a dimeric form of a GlyR beta-subunit receptor-derived peptide. A 2 A crystal structure of the C-terminal domain of gephyrin (GephE) in complex with a 15-residue peptide derived from the GlyR beta-subunit defined the core binding site which we targeted with the dimeric peptide. Biophysical analyses via differential scanning calorimetry (DSC), thermofluor and isothermal titration calorimetry (ITC) demonstrated that this dimeric ligand is capable of binding simultaneously to two receptor binding sites and that this multivalency results in a 25-fold enhanced affinity. Our study therefore suggests that the oligomeric state of gephyrin and the number of gephyrin-binding subunits in the pentameric GABAARs and GlyRs together control postsynaptic receptor clustering.
Modulation of Gephyrin-Receptor Affinity by Multivalency.,Maric HM, Kasaragod VB, Schindelin H ACS Chem Biol. 2014 Aug 19. PMID:25137389[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kirsch J, Wolters I, Triller A, Betz H. Gephyrin antisense oligonucleotides prevent glycine receptor clustering in spinal neurons. Nature. 1993 Dec 23-30;366(6457):745-8. PMID:8264797 doi:http://dx.doi.org/10.1038/366745a0
- ↑ Stallmeyer B, Schwarz G, Schulze J, Nerlich A, Reiss J, Kirsch J, Mendel RR. The neurotransmitter receptor-anchoring protein gephyrin reconstitutes molybdenum cofactor biosynthesis in bacteria, plants, and mammalian cells. Proc Natl Acad Sci U S A. 1999 Feb 16;96(4):1333-8. PMID:9990024
- ↑ Maric HM, Kasaragod VB, Schindelin H. Modulation of Gephyrin-Receptor Affinity by Multivalency. ACS Chem Biol. 2014 Aug 19. PMID:25137389 doi:http://dx.doi.org/10.1021/cb500303a
