Involvement of B‐Raf in Ras‐induced Raf‐1 activation

FEBS Letters

Kaziro, Yoshito¹  Inouye, Kaoru¹  Koide, Hiroshi¹  Mizutani, Shin¹ 

[1] Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan

关键词: Ras;    Raf-1;    B-Raf;    ERK;    extracellular signal-regulated kinase;    GST;    glutathione-S-transferase;    HEK;    human embryonic kidney;    MEK;    mitogen-activated protein kinase/ERK kinase;    RafFH;    Raf-1 with FLAG tag and six histidine residues in its carboxy terminus;    REKS;    Ras-dependent ERK/MEK stimulator;   

DOI  :  10.1016/S0014-5793(01)02992-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The mechanism of Ras-induced Raf-1 activation is not fully understood. Previously, we identified a 400-kDa protein complex as a Ras-dependent Raf-1 activator. In this study, we identified B-Raf as a component of this complex. B-Raf was concentrated during the purification of the activator. Immunodepletion of B-Raf abolished the effect of the activator on Raf-1. Furthermore, B-Raf and Ras-activated Raf-1 co-operatively, when co-transfected into human embryonic kidney 293 cells. On the other hand, Ras-dependent extracellular signal-regulated kinase/mitogen-activated protein kinase kinase stimulator (a complex of B-Raf and 14-3-3) failed to activate Raf-1 in our cell-free system. These results suggest that B-Raf is an essential component of the Ras-dependent Raf-1 activator.

【 授权许可】

Unknown