Premium
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
Author(s) -
Kobayashi Manko,
Hashimoto Naohiro,
Hoshino Masato,
Hattori Seisuke,
Iwashita Shintaro
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)80165-q
Subject(s) - gene product , neurofibromin 1 , transition (genetics) , neurofibromatosis , microbiology and biotechnology , gene , biology , differential effects , chemistry , biochemistry , gene expression , genetics , endocrinology
Using octyl glucoside‐solubilized cell extracts from human fibroblasts during growth phase to G 0 /G 1 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.