Protein kinase C of a human megakaryoblastic leukemic cell line (MEG‐01) Analysis of subspecies and activation by diacylglycerol and free fatty acids

FEBS Letters

Kitagawa, Yasuo¹  Matsuo, Yoshinobu²  Minowada, Jun²  Nishizuka, Yasutomi¹ 

[1] Department of Biochemistry, Kobe University School of Medicine, Kobe 650, Biosignal Research Center, Kobe University, Kobe 657, Japan;Fujisaki Cell Center, Hayashibara Biochemical Laboratories, Inc., Okayama 702, Japan

关键词: Protein kinase C;    Arachidonic acid;    Megakaryocyte;    MEG-01 cell;    PKC;    protein kinase C;    PS;    phosphatidylserine;    DAG;    diacylglycerol;    FFA;    free fatty acid;    EGTA;    ethyleneglycol bis(2-aminoethylether) tetraacetic acid;    EDTA;    ethylenediaminetetraacetic acid;   

DOI  :  10.1016/0014-5793(91)80998-I

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protein kinase C (PKC) from a human megakaryoblastic leukemic cell line (MEG-01) was resolved into two fractions by hydroxyapatite column chromatography, which are indistinguishable from the brain type II (βI/βII) and type III (α) subspecies, by biochemical and immunoblot analysis. In the presence of both phosphatidylserine and diacylglycerol, several free unsaturated fatty acids (FFA's), such as arachidonic, oleic, linoleic and linolenic acids, further enhanced the enzyme activation, and allowed the enzyme to exhibit almost full activity at nearly basal levels of Ca²⁺ concentration. The concentration of unsaturated FFA's giving rise to the maximum enzyme activation was around 2 × 10⁻⁵ M. Palmitic and stearic acids were inactive. The result implies that, in addition to diacylglycerol, the receptor-mediated release of unsaturated FFA's from membrane phospholipids may also take part in the activation of PKC.

【 授权许可】

Unknown