Boivin D, Bilodeau D, Béliveau R
Départment de chimie, Université du Québec a Montréal, Canada.
Can J Physiol Pharmacol. 1996 Jul;74(7):801-10.
The actin cytoskeleton is involved in numerous cellular functions such as cell motility, mitogenesis, morphology, muscle contraction, cytokinesis, and establishment of cell polarity. The members of the Rho subfamily of small GTP-binding proteins emerge as key regulators of cytokeleton organization. Rho, Rac, and CDC42 are implicated in the regulation of actin microfilament organization of different cell structures, such as stress fibers linked to focal adhesions and membrane ruffles induced by extracellular stimuli. Rho proteins also regulate the activity of several enzymes involved in the formation of phospholipid derivatives, which could mediate their effect on the cytoskeleton. The activity of Rho proteins is regulated by many nucleotide exchange factors and GTPase-activating proteins, some of which are oncogene products, and other disease-associated proteins. The potential role of these small GTP-binding proteins in carcinogenesis is suggested by the actin reorganization seen in transforming cells and by the need for functional Rho proteins in Ras mitogenic activation.
肌动蛋白细胞骨架参与众多细胞功能，如细胞运动、有丝分裂、形态形成、肌肉收缩、胞质分裂以及细胞极性的确立。小GTP结合蛋白Rho亚家族成员是细胞骨架组织的关键调节因子。Rho、Rac和CDC42参与不同细胞结构的肌动蛋白微丝组织调节，如与粘着斑相连的应力纤维以及细胞外刺激诱导的膜皱褶。Rho蛋白还调节参与磷脂衍生物形成的几种酶的活性，这可能介导它们对细胞骨架的作用。Rho蛋白的活性受许多核苷酸交换因子和GTP酶激活蛋白调节，其中一些是癌基因产物，还有其他与疾病相关的蛋白。转化细胞中出现的肌动蛋白重组以及Ras有丝分裂激活中功能性Rho蛋白的需求提示了这些小GTP结合蛋白在致癌作用中的潜在作用。
