Qi Maosong, Liu Yuzhen, Freeman Michael R, Solomon Keith R
Department of Orthopaedic Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts 02115, USA.
J Cell Biochem. 2009 Apr 15;106(6):1031-40. doi: 10.1002/jcb.22081.
Dynamic interactions between cellular membranes and the cytoskeleton are known to play major roles in many cellular responses to environmental cues. External signals resulting in proliferation, differentiation, polarization, and motility must be translated from chemical signals into changes of state, often involving the cytoskeleton-dependent altering of cell shape and redistribution of molecules. Cholesterol, a critical component of eukaryotic cell membranes, performs vital roles in regulating membrane dynamics and function. Here we demonstrate, using mesenchymal and epithelial cell lines, that depletion of membrane cholesterol results in Src kinase-mediated Rho activation and caveolin phosphorylation, which together collaborate to form stress fibers. These results demonstrate that cholesterol is a critical regulator of membrane-cytoskeletal dynamics and suggest that altered cholesterol concentrations may result in dramatic changes in cellular responses mediated by the cytoskeleton.
细胞膜与细胞骨架之间的动态相互作用在许多细胞对环境信号的反应中起着重要作用。导致细胞增殖、分化、极化和运动的外部信号必须从化学信号转化为状态变化，这通常涉及依赖细胞骨架改变细胞形状和分子重新分布。胆固醇是真核细胞膜的关键成分，在调节膜动力学和功能方面发挥着重要作用。在这里，我们使用间充质和上皮细胞系证明，膜胆固醇的消耗会导致Src激酶介导的Rho激活和小窝蛋白磷酸化，它们共同协作形成应力纤维。这些结果表明，胆固醇是膜-细胞骨架动力学的关键调节因子，并表明胆固醇浓度的改变可能导致由细胞骨架介导的细胞反应发生显著变化。
