Muscarinic acetylcholine receptors regulation and protein phosphorylation in primary cultures of rat cerebellum.
Exposure of primary cell cultures of rat cerebellum to the muscarinic agonist carbachol led to a 50% loss in apparent muscarinic receptor number detectable in a ligand binding assay using [3H]quinuclidinyl benzilate ([3H]QNB). The loss in [3H]QNB binding was time-dependent with a half-life of 2.9 h. Examination of membrane protein phosphorylation indicated that exposure to carabachol resulted in an increase in the level of phosphorylation of 6 polypeptides. The increased phosphorylation of 3 of these polypeptides, of molecular weights, 75,000, 67,000 and 62,000, followed a similar time-course to that of carbachol-induced loss of receptor binding. These results are consistent with the idea that the muscarinic receptor regulation involves a protein phosphorylation mechanism.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002531:Cerebellum / Q000187:drug effects* / Q000378:metabolism; D046508:Culture Techniques; D008565:Membrane Proteins / Q000378:metabolism*; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000378:metabolism
D008565:Membrane Proteins; D010455:Peptides; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate; D002217:Carbachol; D000109:Acetylcholine