Possible involvement of calpain in down-regulation of protein kinase C.
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.
Adachi
Y
Y
Department of Clinical Science and Laboratory Medicine, Faculty of Medicine, Kyoto University, Japan.
Maki
M
M
Ishii
K
K
Hatanaka
M
M
Murachi
T
T
D000595:Amino Acid Sequence; D002154:Calpain / Q000037:antagonists & inhibitors / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000378:metabolism; D009447:Neuroblastoma / Q000473:pathology; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D009363:Neoplasm Proteins; D011493:Protein Kinase C; D002154:Calpain; D013755:Tetradecanoylphorbol Acetate