Activation of protein kinase C by the 14‐3‐3 proteins homologous with Exol protein that stimulates calcium‐dependent exocytosis

FEBS Letters

Ichimura, Tohru²  Okuyama, Tsuneo²  Nakajo, Shigeo¹  Takahashi, Nobuhiro³  Nakaya, Kazuyasu¹  Hiyane, Yuriko²  Isobe, Toshiaki² 

[1] Laboratory of Biochemistry, Pharmaceutical Sciences, Showa University, Shinagawa-ku, Tokyo 142, Japan;Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Hachloji-shi, Tokyo 192-03, Japan;Corporate Research and Development Laboratory, Tonen, K.K., Irumagun, Saitama 354, Japan

关键词: Signal transduction;    Ca2+-dependent exocytosis;    Protein kinase C;    PKII;    Ca2+/calmodulin-dependent protein kinase type 11;    TH;    tyrosine hydroxylase;    TRH;    tryptophan hydroxylase;    MPLC;    high performance liquid chromatography;   

DOI  :  10.1016/0014-5793(92)81257-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The 14-3-3 proteins are a family of acidic proteins found mainly in the brain and are suggested to have a role in monoamine synthesis based on their ability to activate tyrosine and tryptophan hydroxylases in the presence of type II Ca²⁺/calmodulin-dependent protein kinase. Recently, however, it has been demonstrated that a member of the 14-3-3 family, termed Exol, stimulates Ca²⁺-dependent exocytosis in permeabilized adrenal chromaffin cells, suggesting that this protein family may influence the protein kinase C-mediated control of Ca²⁺-dependent exocytosis. Here we show that the 14-3-3 proteins activate protein kinase C at about 2-fold more than the known level of the activated protein kinase, i.e. the activity of protein kinase C in the presence of Ca²⁺ and phospholipids. This raises the possibility that the cellular activity of protein kinase C is regulated by diverse members of the 14-3-3 family and that the reported ability of Exol to reactivate Ca²⁺-dependent exocytosis is based on its stimulatory effect on protein kinase C activity. The 14-3-3 family, therefore, appears to be a multifunctional regulator of cell signalling processes mediated by two types of Ca²⁺-dependent protein kinase, protein kinase C and type II calmodulin-dependent protein kinase.

【 授权许可】

Unknown