Adachi Y, Maki M, Ishii K, Hatanaka M, Murachi T
Department of Clinical Science and Laboratory Medicine, Faculty of Medicine, Kyoto University, Japan.
Adv Second Messenger Phosphoprotein Res. 1990;24:478-84.
Calpain is known to play a variety of cellular functions in various cells by Ca2(+)-dependent limited proteolysis. Protein kinase C (PK-C) is a key enzyme in signal transduction. It is known that treatment of a cell with 12-0-tetradecanoylphorbol 13-acetate (TPA) causes down-regulation of PK-C, and that calpain can cleave PK-C into catalytic and regulatory fragments in vitro. In vivo involvement of calpain in down-regulation of PK-C was studied with neuroblastoma cells using various drugs, a synthetic peptide fragment of calpastatin and inhibitors against calpain. TPA-dependent down-regulation of PK-C was partially inhibited by pre-treatment with calpastatin peptide and inhibitors, suggesting in vivo involvement of calpain in down-regulation of PK-C during signal transduction.
已知钙蛋白酶通过Ca2(+)依赖性有限蛋白水解在各种细胞中发挥多种细胞功能。蛋白激酶C（PK-C）是信号转导中的关键酶。已知用12-0-十四烷酰佛波醇13-乙酸酯（TPA）处理细胞会导致PK-C下调，并且钙蛋白酶可在体外将PK-C切割成催化片段和调节片段。利用各种药物、钙蛋白酶抑制蛋白的合成肽片段和钙蛋白酶抑制剂，在神经母细胞瘤细胞中研究了钙蛋白酶在PK-C下调中的体内作用。用钙蛋白酶抑制蛋白肽和抑制剂预处理可部分抑制TPA依赖性的PK-C下调，这表明在信号转导过程中钙蛋白酶在体内参与了PK-C的下调。
