RAPID AGONIST MEDIATED PHOSPHORYLATION OF THE METABOTROPIC GLUTAMATE-RECEPTOR 1-ALPHA BY PROTEIN-KINASE-C IN PERMANENTLY TRANSFECTED BHK CELLS

Clonal BHK cells permanently transfected with the metabotropic glutama te receptor 1 alpha (mGluR1 alpha), which is coupled to phospholipase C, were used to study the phosphorylation state of the receptor, Cells were labelled with (PO43-)-P-32, lysed, the receptor immunoprecipitat ed with specific anti-peptide antibodies and the immunoprecipitates an alysed by SDS-PAGE followed by autoradiography. A significant basal le vel of receptor phosphorylation was observed which was rapidly and tra nsiently increased in response to agonist activation of the receptor, This agonist effect was found to be dose dependent with a rapid time c ourse and could be abolished by the specific PKC inhibitor Ro318220, s uggesting that PKC was responsible for the agonist mediated phosphoryl ation of the receptor.