Purified protein kinase C phosphorylates microtubule-associated protein 2.
We have investigated actions of purified protein kinase C on microtubule- and microfilament-related proteins. Among the cytoskeletal proteins examined, microtubule-associated protein 2 (MAP2) was found to serve as a good substrate. Other cytoskeletal proteins, tubulin, fodrin, cofilin, tropomyosin, and 53,000-Da protein, were very poorly phosphorylated. The amino acid residues of MAP2 that were phosphorylated by the protein kinase C were almost exclusively serine. The peptide mapping analysis indicated that protein kinase C and cAMP-dependent protein kinase phosphorylate MAP2 differently. The ability of MAP2 to interact with actin was markedly reduced by this protein kinase C-mediated phosphorylation. These data raise the possibility that phosphorylation of MAP2 by activated protein kinase C may be involved in cell-surface signal transduction.
D000199:Actins / Q000378:metabolism; D000818:Animals; D002147:Calmodulin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008840:Microfilament Proteins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000302:isolation & purification / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D011817:Rabbits; D012694:Serine / Q000378:metabolism; D013379:Substrate Specificity; D013552:Swine; D014404:Tubulin / Q000378:metabolism
D000199:Actins; D002147:Calmodulin; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins; D014404:Tubulin; D012694:Serine; D000242:Cyclic AMP; D011494:Protein Kinases; D011493:Protein Kinase C