抄録
The point-mutated active form of ras p21 is known to activate mitogen-activated protein (MAP) kinase/ extracellular signal-regulated kinase (ERK) in intact mammalian cells and Xenopus oocytes, although the direct target molecule of ras p21 remains to be identified. To elucidate the role of the post-translational processing of ras p21 for the MAP kinase activation, we established the cell-free system in which ras p21 activated MAP kinase. The guanosine 5′-(3-O-thio)triphosphate (GTPγS) bound form of post-translationally processed Ki-ras 4B p21 activated MAP kinase in the cytosol fraction of Xenopus oocytes, but the GTPγS bound form of post-translationally unprocessed Ki-ras 4B p21 or the GDP bound form of processed or unprocessed Ki-ras 4B p21 was far less effective. The GTPγS bound form of processed Ki-ros 4B p21 activated recombinant ERK2 in the presence of the cytosol fraction of Xenopus oocytes, but the unprocessed protein was far less effective. These results provide a complete biochemical assay for ras p21 to activate MAP kinase in a cell-free system and indicate that all the elements downstream of ras p21 necessary for the MAP kinase activation are cytosolic and that the post-translational processing of ras p21 is important for the MAP kinase activation.
本文言語 | 英語 |
---|---|
ページ(範囲) | 3025-3028 |
ページ数 | 4 |
ジャーナル | Journal of Biological Chemistry |
巻 | 268 |
号 | 5 |
出版ステータス | 出版済み - 15-02-1993 |
外部発表 | はい |
All Science Journal Classification (ASJC) codes
- 生化学
- 分子生物学
- 細胞生物学