Open AccessWidespread occurrence of "87 kDa," a major specific substrate for protein kinase C.
Author(s) -
Katherine A. Albert,
S. Ivar Walaas,
J K Wang,
Paul Greengard
Publication year - 1986
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.83.9.2822
Subject(s) - phosphoprotein , biology , biochemistry , protein kinase a , molecular mass , microbiology and biotechnology , protein kinase c , isoelectric point , protein a/g , cytosol , kinase , phosphorylation , enzyme , fusion protein , gene , recombinant dna
An 87-kDa phosphoprotein, identified previously as a major, specific substrate for Ca2+/phospholipid/diacylglycerol-dependent protein kinase (protein kinase C) in broken cell preparations from rat brain, has been characterized with respect to its species, tissue, and subcellular distribution. A similar protein was present in monkey, human, mouse, and bovine brain and in Torpedo californica electric organ. The protein was also identified in a variety of nonneuronal rat and bovine tissues. The rat protein had an apparent molecular mass 4-7 kDa lower, and was slightly more acidic, than the protein in bovine tissues. The 87-kDa proteins from various bovine tissues were identical by the following criteria: each was phosphorylated by exogenous protein kinase C, was of comparable molecular mass, generated multiple spots within the pH range of 4.4-4.9 upon isoelectric focusing, yielded identical patterns upon digestion with Staphylococcus aureus V8 protease, and was recognized by a specific 87-kDa antiserum. The relative concentrations of the 87-kDa protein in bovine tissues were highest in brain, spleen, and lung, moderate in testis, pancreas, adrenal, kidney, and liver, and lowest in heart and skeletal muscle. In the brain, the 87-kDa protein was concentrated in the synaptosomal membrane and in the cytosol. The membrane-bound protein was extractable with nonionic detergents but not with NaCl. This species, tissue, and subcellular distribution of the 87-kDa protein is similar to that of protein kinase C.