Interaction between GABA(A) receptor beta subunits and the multifunctional protein gC1q-R
| Autor: | Sabine W. Baumann, Martin T. Schaerer, Erwin Sigel, Kai Kannenberg, Peter Hunziker |
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| Rok vydání: | 2001 |
| Předmět: |
Membrane Glycoproteins
Protein subunit Cell Biology Receptor Cross-Talk Biology Receptors GABA-A Biochemistry Gamma-aminobutyric acid receptor subunit alpha-1 Hippocampus GABAA-rho receptor Interleukin 10 receptor alpha subunit Rats Receptors Complement Mitochondrial Proteins Hyaluronan Receptors Animals 5-HT5A receptor Cattle Phosphorylation Receptor Molecular Biology Cys-loop receptors Signal Transduction |
| Zdroj: | The Journal of biological chemistry. 276(28) |
| ISSN: | 0021-9258 |
| Popis: | gamma-Aminobutyric acid type A (GABA(A)) receptors were immunopurified from bovine brain using a monoclonal antibody directed against the alpha1 subunit. Of the several proteins that copurified, a 34-kDa protein was analyzed further. After enrichment and tryptic proteolysis, the resulting fragments were sequenced, and the protein was identified as gC1q-R. Using anti-gC1q-R and anti-GABA(A) receptor antibodies, mutual coimmunoprecipitation could be demonstrated from solubilized rat brain membranes. The stability of this interaction was estimated to be very high. Using the yeast two-hybrid system, various GABA(A) receptor subunit intracellular loop constructs were tested for an interaction with gC1q-R. All beta subunits, but not alpha 1 and gamma 2 subunits, were found to bind to gC1q-R. NH(2)- and COOH-terminally truncated beta 2 subunit loops were used to find the region responsible for the interaction with gC1q-R. A stretch of 15 amino acids containing 7 positively charged residues was identified (amino acids 399--413). This region contains residue Ser-410, which is a protein kinase substrate, and it is known that phosphorylation of this residue leads to an alteration in receptor activity. Localization studies suggested a predominantly intracellular localization. Our observations therefore suggest a tight interaction between gC1q-R and the GABA(A) receptor which might be involved in receptor biosynthesis or modulation of the mature function. |
| Databáze: | OpenAIRE |
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