Mertens Alexander E E, Pegtel D Michiel, Collard John G
Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
Trends Cell Biol. 2006 Jun;16(6):308-16. doi: 10.1016/j.tcb.2006.04.001. Epub 2006 May 2.
Cell polarity is an essential requirement for the proper tissue development of complex organisms. This is underscored by in vivo studies showing that loss of cell polarity contributes to the formation and progression of tumours. Evolutionary conserved multiprotein complexes, such as the Par3-Par6-aPKC or, in short, the Par polarity complex, regulate the establishment of cell polarity. The small Rho GTPases CDC42 and Rac control the activation of the Par polarity complex. Evidence now implicates the Rac activator Tiam1 as a crucial component of the Par complex in regulating neuronal (axonal) and epithelial (apical-basal) polarity. Our current knowledge places Tiam1 at the centre of a pivotal biological process, the establishment and maintenance of cell polarity, and suggests that deregulation of the Tiam1-Par complex contributes to tumourigenicity.
细胞极性是复杂生物体正常组织发育的基本要求。体内研究强调了这一点，这些研究表明细胞极性的丧失会促进肿瘤的形成和发展。进化保守的多蛋白复合物，如Par3-Par6-aPKC，或简称为Par极性复合物，调节细胞极性的建立。小Rho GTP酶CDC42和Rac控制Par极性复合物的激活。现在有证据表明，Rac激活剂Tiam1作为Par复合物的关键成分，参与调节神经元（轴突）和上皮（顶-基）极性。我们目前的知识表明，Tiam1处于关键生物学过程——细胞极性的建立和维持的核心位置，并表明Tiam1-Par复合物的失调会导致肿瘤发生。
