A novel membrane factor stimulates guanine nucleotide exchange reaction of ras proteins

FEBS Letters

Kung, Hsiang-fu¹  Kamata, Tohru²  West, Michael² 

[1] Laboratory of Biochemical Physiology, Biological Response Modifiers Program, Division of Cancer Treatment, National Cancer Institute, Frederick Cancer Research Facility, P.O. Box B, Frederick, MD 21701, USA;Biological Carcinogenesis and Development Program, Program Resources, Inc., USA

关键词: Ras protein;    GDP/GTP exchange reaction;    GTP-binding protein;    Signal transduction;   

DOI  :  10.1016/0014-5793(90)80019-F

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A factor with a molecular weight of 100 kDa, which markedly enhanced the guanine nucleotide exchange reaction of ras p21 proteins, was partially purified from bovine brain tissues. The factor was predominantly associated with the plasma membrane. When the partially purified factor and excess cold GTP were added to [³H]GDPGly12 p21 or Vall2 p21 in the presence of 2 mM MgCl₂, the nucleotide exchange rate was stimulated up to 25-fold. The stimulation of the p21-nucleotide exchange reaction by the factor was completely blocked by the Y13-259 ras-neutralizing antibody. Taken together, these results suggest that the factor may control the rate limiting GDP/GTP exchange step in recycling of p21 in ras-mediated signal transduction.

【 授权许可】

Unknown