Analysis of guanine nucleotide bound to ras protein in PC12 cells

FEBS Letters

Kaziro, Yoshito¹  Satoh, Takaya¹  Endo, Masami¹  Nakamura, Shun¹ 

[1]Institute of Medical Science, University of Tokyo, 4-6-1, Shirokanedai, Minatoku, Tokyo 108, Japan

关键词: ras protein;    Nucleotide exchange;    (PC12 cell);    GTPγS;    guanosine 5′-O-(3-thiotriphosphate);    GDPβS;    guanosine 5′-O-(2-thiodiphosphate);   

DOI  :  10.1016/0014-5793(88)80311-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The ras gene product (p21) specifically binds GDP or GTP. In analogy with the reaction mechanism of other GTP-binding proteins, only the GTP-bound conformation is believed to be the biologically active one. Previously, we reported that not only oncogenic p21 (Val-12) but also proto-oncogenic p21(Gly-12) could induce morphological differentiation in rat pheochromocytoma PC12 cells when microinjected in the complexed form with GTPγS [(1987) Mol. Cell. Biol. 7, 4553–4556]. In the present report we transformed PC12 cells with the oncogenic ras gene placed under the metallothionein I promoter. It was found that the transformed cells, when induced with Cd²⁺, differentiated in the absence of NGF. Then we analyzed the guanine nucleotide bound to p21 in the intact PC12 cells. It was found that conditionally induced p21(Val-12) was mostly present in the GTP-bound form, whereas the endogenous p21(Gly-12) was in the GDP-bound form. These results indicate again that p21·GTP induces the morphological differentiation of PC12 cells.

【 授权许可】

Unknown