Osada S, Izawa M, Koyama T, Hirai S, Ohno S
Department of Molecular Biology, Yokohama City University School of Medicine, Kanazawa-ku, Japan.
FEBS Lett. 1997 Mar 10;404(2-3):227-33. doi: 10.1016/s0014-5793(97)00139-7.
The molecular bases of the versatile functions of Rho-like GTPases are still unknown. Using luciferase assays with rat 3Y1 cells, we found that Rac1 is integrated downstream of Ras in the TRE (TPA response element) activation pathway. Coexpression of a mutant of p65PAK, PAK/RD, lacking the kinase domain but containing the Cdc42/Rac interactive binding (CRIB) region, suppressed the TRE activation and cell transformation caused by constitutively activated forms of Ras (RasV12) and Rac1 (Rac1V12). PAK/RD is a good tool to investigate the signaling pathways in which Rac and Cdc42 are involved.
Rho样GTP酶多种功能的分子基础仍然未知。通过对大鼠3Y1细胞进行荧光素酶检测，我们发现Rac1在TRE（佛波酯反应元件）激活途径中整合于Ras下游。缺乏激酶结构域但含有Cdc42/Rac相互作用结合（CRIB）区域的p65PAK突变体PAK/RD的共表达，抑制了由组成型激活形式的Ras（RasV12）和Rac1（Rac1V12）引起的TRE激活和细胞转化。PAK/RD是研究Rac和Cdc42所涉及的信号通路的良好工具。
