Filtern
Volltext vorhanden
- ja (2)
Gehört zur Bibliographie
- ja (2)
Dokumenttyp
Sprache
- Englisch (2)
Schlagworte
- GABA(A) receptors (1)
- cellular neuroscience (1)
- containing GABA(A) receptors (1)
- cultured hippocampal-neurons (1)
- exchange factor collybistin (1)
- gamma-aminobutyric-acid (1)
- gephyrin (1)
- glycine (1)
- inhibitory synapse (1)
- ion channels in the nervous system (1)
- molybdenum cofactor biosynthesis (1)
- neurotransmitters (1)
- rat spinal-cord (1)
- receptor clustering (1)
- receptor-beta subunits (1)
- scaffolding protein gephyryrin (1)
- synapse formation (1)
- synaptic development (1)
- temporal-lobe epilepsy (1)
Institut
- Rudolf-Virchow-Zentrum (2) (entfernen)
EU-Projektnummer / Contract (GA) number
- 202088 (1)
Fast inhibitory synaptic transmission is mediated by γ-aminobutyric acid type A receptors (GABAARs) that are enriched at functionally diverse synapses via mechanisms that remain unclear. Using isothermal titration calorimetry and complementary methods we demonstrate an exclusive low micromolar binding of collybistin to the α2-subunit of GABAARs. To explore the biological relevance of collybistin-α2-subunit selectivity, we generate mice with a mutation in the α2-subunit-collybistin binding region (Gabra2-1). The mutation results in loss of a distinct subset of inhibitory synapses and decreased amplitude of inhibitory synaptic currents. Gabra2–1 mice have a striking phenotype characterized by increased susceptibility to seizures and early mortality. Surviving Gabra2-1 mice show anxiety and elevations in electroencephalogram δ power, which are ameliorated by treatment with the α2/α3-selective positive modulator, AZD7325. Taken together, our results demonstrate an α2-subunit selective binding of collybistin, which plays a key role in patterned brain activity, particularly during development.
GABA(A) receptors are clustered at synaptic sites to achieve a high density of postsynaptic receptors opposite the input axonal terminals. This allows for an efficient propagation of GABA mediated signals, which mostly result in neuronal inhibition. A key organizer for inhibitory synaptic receptors is the 93 kDa protein gephyrin that forms oligomeric superstructures beneath the synaptic area. Gephyrin has long been known to be directly associated with glycine receptor beta subunits that mediate synaptic inhibition in the spinal cord. Recently, synaptic GABA(A) receptors have also been shown to directly interact with gephyrin and interaction sites have been identified and mapped within the intracellular loops of the GABA(A) receptor alpha 1, alpha 2, and alpha 3 subunits. Gephyrin-binding to GABA(A) receptors seems to be at least one order of magnitude weaker than to glycine receptors (GlyRs) and most probably is regulated by phosphorylation. Gephyrin not only has a structural function at synaptic sites, but also plays a crucial role in synaptic dynamics and is a platform for multiple protein-protein interactions, bringing receptors, cytoskeletal proteins and downstream signaling proteins into close spatial proximity.