Circadian and photic regulation of MAP kinase by Ras‐ and protein phosphatase‐dependent pathways in the chick pineal gland

FEBS Letters

Hayashi, Yuichiro¹  Sanada, Kamon¹  Fukada, Yoshitaka¹ 

[1] Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-Ku, Tokyo 113-0033, Japan

关键词: Circadian rhythm;    Photic entrainment;    Pineal gland;    Mitogen-activated protein kinase;    Protein phosphatase;    Chicken;    SCN;    suprachiasmatic nucleus;    MAPK;    mitogen-activated protein kinase;    MEK;    MAPK/ERK kinase;    PAGE;    polyacrylamide gel electrophoresis;    RBD;    Ras-binding domain;    GST;    glutathione S-transferase;    CT;    circadian time;   

DOI  :  10.1016/S0014-5793(01)02153-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Chick pineal mitogen-activated protein kinase (MAPK) exhibits circadian activation and light-dependent deactivation at nighttime. Here we report that, in the chick pineal gland, levels of active forms of MAPK, MEK, Raf-1 and Ras exhibited synchronous circadian rhythms with peaks during the subjective night, suggesting a sequential activation of components in the classical Ras-MAPK pathway in a circadian manner. In contrast, the light-dependent deactivation of MAPK was not accompanied by any change of MEK activity, but it was attributed to the light-dependent activation of protein phosphatase dephosphorylating MAPK. These results indicate that the photic and clock signals regulate MAPK activity via independent pathways, and suggest a pivotal role of MAPK in photic entrainment and maintenance of the circadian oscillation.

【 授权许可】

Unknown