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Basic Protein in Brain Myelin Is Phosphorylated by Endogenous Phospholipid‐Sensitive Ca 2+ ‐Dependent Protein Kinase
Author(s) -
Turner R. Scott,
Chou C.H. Jen,
Kibler Robert F.,
Kuo J. F.
Publication year - 1982
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1982.tb12583.x
Subject(s) - phosphatidylserine , myelin basic protein , protein kinase a , calmodulin , biochemistry , protein kinase c , phosphorylation , melittin , protein phosphorylation , myelin , biology , kinase , phospholipid , egta , chemistry , microbiology and biotechnology , calcium , enzyme , peptide , organic chemistry , membrane , central nervous system , neuroscience
Phosphorylation of myelin basic protein (MBP) in rat or rabbit brain myelin was markedly stimulated by Ca 2+ , and this reaction was not essentially augmented by exogenous phosphatidylserine or calmodulin or both. Solubilization of myelin with 0.4% Triton X‐100 plus 4 m M EGTA, with or without further fractionation, showed that Ca 2+ ‐dependent phosphorylation of MBP required phosphatidylserine, but not calmodulin. DEAE‐cellulose chromatography of solubilized myelin revealed a pronounced peak of protein kinase activity stimulated by a combination of Ca 2+ and phosphatidylserine; a protein kinase stimulated by Ca 2+ plus calmodulin was not detected. These findings clearly indicate an involvement of phospholipid‐sensitive Ca 2+ ‐dependent protein kinase in phosphorylation of brain MBP, although a possible role for the calmodulin‐sensitive species of Ca 2+ ‐dependent protein kinase in this reaction could not be excluded or established. Phosphorylation of MBP in solubilized rat myelin catalyzed by the phospholipid‐sensitive enzyme was inhibited by adriamycin, palmitoylcarnitine, trifluoperazine, melittin, polymyxin B, and N ‐(6‐aminohexyl)‐5‐chloro‐l‐naphthalenesulfonamide (W–7).