Role of the PLC-related, catalytically inactive protein p130 in GABAA receptor function

Abstract

The protein p130 was isolated from rat brain as an inositol 1,4,5-trisphosphate-binding protein with a domain organization similar to that of phospholipase C-delta1 but lacking PLC activity. We show that p130 plays an important role in signaling by the type A receptor for gamma-aminobutyric acid (GABA). Yeast twohybrid screening identified GABARAP (GABA(A) receptor-associated protein), which is proposed to contribute to the sorting, targeting or clustering of GABA(A) receptors, as a protein that interacts with p130. Furthermore, p130 competitively inhibited the binding of the gamma2 subunit of the GABA(A) receptor to GABARAP in vitro. Electrophysiological analysis revealed that the modulation of GABA-induced Cl- current by Zn2+ or diazepam, both of which act at GABA(A) receptors containing gamma subunits, is impaired in hippocampal neurons of p130 knockout mice. Moreover, behavioral analysis revealed that motor coordination was impaired and the intraperitoneal injection of diazepam induced markedly reduced sedative and antianxiety effects in the mutant mice. These results indicate that p130 is essential for the function of GABA(A) receptors, especially in response to the agents acting on a gamma2 subunit.

Dependence-induced increases in ethanol self-administration in mice are blocked by the CRF1 receptor antagonist antalarmin and by CRF1 receptor knockout

“…Methylcellulose is a safe (LD50 in mice ∼250 g/kg) intraperitoneal vehicle for lipophilic drugs (e.g. Akiyama et al, 1999;Kanematsu et al, 2002;O'Connor et al, 2000). The injections occurred 1 hour prior to operant selfadministration testing.…”

GABAAReceptor Phospho-Dependent Modulation Is Regulated by Phospholipase C-Related Inactive Protein Type 1, a Novel Protein Phosphatase 1 Anchoring Protein

“…The recombinant proteins were expressed in Escherichia coli and purified by affinity chromatography. Pull-down assays using these recombinant molecules were performed as described previously Hanley et al, 1999;Yoshimura et al, 2001;Kanematsu et al, 2002).…”

“…PRIP-1 has a number of binding partners, including catalytic subunit of protein phosphatase 1␣ (PP1␣) and GABA A receptor-associated protein (GABARAP) Yoshimura et al, 2001; Kanematsu et al, 2002). A role for PRIP-1 in regulating GABA A receptor function is further suggested by the phenotype of PRIP-1 knock-out (PRIP-1 Ϫ/Ϫ ) mice, which have altered GABA A receptor pharmacology and behavior .…”

Sustained Structural Change of GABAA Receptor-Associated Protein Underlies Long-Term Potentiation at Inhibitory Synapses on a Cerebellar Purkinje Neuron

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