Differential contribution of M r 120 kDa rasGTPase‐activating protein and neurofibromatosis type 1 gene product during the transition from growth phase to arrested state in human fibroblasts accompanied by a unique rasGTPase‐activating active

FEBS Letters

Hoshino, Masato²  Hattori, Seisuke¹  Kobayashi, Manko²  Iwashita, Shintaro²  Hashimoto, Naohiro² 

[1] National Institute of Neuroscience, Kodaira-shi, Tokyo 187, Japan;Mitsubishi Kasei Institute of Life Sciences, Machida-shi, Tokyo 194, Japan

关键词: Ras;    GTPase-activating protein;    Neurofibromatosis type 1 gene product;    Cell growth arrest;    Human fibroblast;    GAP;    GTPase-activating protein;    pl20GAP;    GAP molecule with M r;    120 kDa;    NF1;    neurofibromatosis type 1 gene product;    NF1-GRD;    NF1 GAP-related domain;    DTT;    dithiothreitol;    TBST;    Tris-buffered saline containing Tween 20;   

DOI  :  10.1016/0014-5793(93)80165-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Using octyl glucoside-solubilized cell extracts from human fibroblasts during growth phase to G₀/G₁ arrest state, we found that while the number of M _r, 120 kDa rasGTPase-activating protein (p120GAP) molecules per cell decreases to half its original levels, the amount of neurofibromatosis type 1 gene product (NF1, neurofibromin) remains constant during the transition. The contribution of pl20GAP to the total rasGTPase-activating (rasGA) activity in growing cells was found to be larger than that observed in arrested cells (84% vs 53%). On the other hand, NF1 contributes less than 15% of the total rasGA activity in either extract. These results indicate that the qualitative changes occur in the contributors to rasGA activity during transition. They also suggest that a unique rasGA activity exists in the arrested cells, which was obtained separatedly from both pl20GAP and NF1 by heparin-Sepharose column chromatography.

【 授权许可】

Unknown