Selective suppression of stress‐activated protein kinase pathway by protein phosphatase 2C in mammalian cells

FEBS Letters

Hiraga, Akira¹  Katsura, Koji¹  Yanagawa, Yuchio¹  Tamura, Shinri¹  Wang, Hong¹  Kobayashi, Takayasu¹  Hanada, Masahito¹  Ohnishi, Motoko¹  Kanamaru, Ryunosuke²  Ikeda, Shoko¹ 

[1] Department of Biochemistry, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryomachi, Aoba-ku, Sendai 980-8575, Japan;Department of Clinical Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980, Japan

关键词: Protein phosphatase 2C;    Stress-activated protein kinase signal pathway;   

DOI  :  10.1016/S0014-5793(98)01229-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protein phosphatase 2Cα (PP2Cα) or PP2Cβ-1 expressed in COS7 cells suppressed anisomycin- and NaCl-enhanced phosphorylations of p38 co-expressed in the cells. PP2Cα or PP2Cβ-1 expression also suppressed both basal and stress-enhanced phosphorylations of MKK3b and MKK6b, which are upstream protein kinases of p38, and of MKK4, which is one of the major upstream protein kinases of JNK. Basal activity of MKK7, another upstream protein kinase of JNK, was also suppressed by PP2Cα or PP2Cβ-1 expression. However, basal as well as serum-activated phosphorylation of MKK1a, an upstream protein kinase of ERKs, was not affected by PP2Cβ or PP2Cβ-1. A catalytically inactive mutant of PP2Cβ-1 further enhanced the NaCl-stimulated phosphorylations of MMK3b, MKK4 and MKK6b, suggesting that this mutant PP2Cβ-1 works as a dominant negative form. These results suggest that PP2C selectively inhibits the SAPK pathways through suppression of MKK3b, MKK4, MKK6b and MKK7 activities in mammalian cells.

【 授权许可】

Unknown