Brain Protein Kinase C Phosphorylating poly(Arginine,Serine) or Lamin B is Stimulated by Anions and by an Activator Purified from Bovine Serum Albumin Preparations

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 86; no. 6; pp. 1761 - 1765
• Main Authors: Abdel-Ghany, M., El-Gendy, K., Zhang, S., Raden, D., Racker, E.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.03.1989; National Acad Sciences
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Anions; Antibodies; Biological and medical sciences; bovine serum albumin; brain; Brain - enzymology; Cell membranes; Cytosol; Enzyme Activation - drug effects; Fundamental and applied biological sciences. Psychology; Histones; Histones - metabolism; Humans; Isoenzymes - metabolism; Lamin Type B; Lamins; Lipids; Nuclear Proteins - metabolism; Peptides - metabolism; Phosphates - pharmacology; Phosphorylation; Placenta - analysis; Protein Kinase C - antagonists & inhibitors; Protein Kinase C - metabolism; Proteins; Rats; Serum Albumin, Bovine - analysis; Serum Albumin, Bovine - pharmacology; Serum albumins; Sheep; Substrate Specificity; Sulfates - pharmacology; Swine; Ungulates; Brain; Phosphorylation; Protein kinase C; Purification; Calcium; Radiolabelling; Rat; Gel electrophoresis; Serine; Rodentia; Lipids; Stimulation; Activation; Proteins; Vertebrata; Anions; Mammalia; Enzymatic activity; Arginine; Affinity chromatography; Inhibition; Histone
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.86.6.1761

The phosphorylation of histone by purified protein kinase C (PK-C) from rat brain is dependent on the presence of Ca2+ and lipids. Phosphorylation of a synthetic random polymer of arginine and serine (3:1) is only moderately enhanced by Ca2+ and lipids, but it is greatly enhanced in the absence of Ca2+ and lipids by a contaminant in crystalline bovine serum albumin or by heated cellular fractions. The phosphorylation ration of histone to poly(arginine,serine) varies between different PK-C fractions from brains of rat, pig, or lamb. These variations are partly caused by a PK-C isozyme that prefers poly(arginine,serine) over histone as substrate. The kinase activator (KA) was partly purified from bovine serum albumin and from extracts of plasma membranes of human placenta. KA is also present in mitochondria, nuclei, and the cytosol. Sulfates and phosphates at 10 mM substitute for KA with poly(arginine,serine) as substrate. The phosphorylation of histone III in the presence of Ca2+ and lipids is moderately stimulated by KA, but the phosphorylation of lamin B and some other endogenous proteins is greatly enhanced by KA. With histones as substrates, inorganic anions do not stimulate phosphorylation. The phosphorylation of poly(arginine,serine) is very sensitive to low concentrations of staurosporin and is inhibited by PK-C antibody, but, in contrast to histone phosphorylation, it is resistant to sphingosine and polymyxin B. The poly(arginine,serine) phosphorylating activity is more stable at 4 degrees C than the histone phosphorylating activity, but the latter is stabilized by 0.05% Triton X-100.