Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
FEBS Lett. 2011 Feb 18;585(4):618-22. doi: 10.1016/j.febslet.2011.01.035. Epub 2011 Feb 1.
Arachidonic acid (AA) stimulates cell adhesion through a p38 mitogen activated protein kinase-mediated RhoA signaling pathway. Here we report that a proteomic screen following AA-treatment identified nucleolin, a multifunctional nucleolar protein, in a complex with the GTPase, RhoA, that also included the Rho kinase, ROCK. AA-stimulated cell adhesion was inhibited by expression of nucleolin-targeted shRNA and formation of the multiprotein complex was blocked by expression of dominant-negative RhoA. AA-treatment also induced ROCK-dependent serine phosphorylation of nucleolin and translocation of nucleolin from the nucleus to the cytoplasm, where it appeared to co-localize with RhoA. These data suggest the existence of a new signaling pathway through which the location and post-translational state of nucleolin are modulated.
花生四烯酸（AA）通过 p38 丝裂原活化蛋白激酶介导的 RhoA 信号通路刺激细胞黏附。在这里，我们报告说，AA 处理后的蛋白质组学筛选鉴定出核仁素，一种多功能核仁蛋白，与 GTP 酶 RhoA 形成复合物，该复合物还包括 Rho 激酶 ROCK。核仁素靶向 shRNA 的表达抑制了 AA 刺激的细胞黏附，并且显性负性 RhoA 的表达阻断了多蛋白复合物的形成。AA 处理还诱导了 ROCK 依赖性丝氨酸磷酸化核仁素和核仁素从细胞核到细胞质的易位，在细胞质中它似乎与 RhoA 共定位。这些数据表明存在一种新的信号通路，通过该通路调节核仁素的位置和翻译后状态。
