Murphy A M, Montell D J
Department of Biological Chemistry, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205-2185, USA.
J Cell Biol. 1996 May;133(3):617-30. doi: 10.1083/jcb.133.3.617.
The Rho subfamily of GTPases has been shown to regulate cellular morphology. We report the discovery of a new member of the Rho family, named RhoL, which is equally similar to Rac, Rho, and Cdc42. Expression of a dominant-negative RhoL transgene in the Drosophila ovary caused nurse cells to collapse and fuse together. Mutant forms of Cdc42 mimicked this effect. Expression of constitutively active RhoL led to nurse cell subcortical actin breakdown and disruption of nurse cell-follicle cell contacts, followed by germ cell apoptosis. In contrast, Rac activity was specifically required for migration of a subset of follicle cells called border cells. All three activities were necessary for normal transfer of nurse cell cytoplasm to the oocyte. These results suggest that Rho protein activities have cell type-specific effects on morphogenesis.
GTP 酶的 Rho 亚家族已被证明可调节细胞形态。我们报告发现了 Rho 家族的一个新成员，命名为 RhoL，它与 Rac、Rho 和 Cdc42 的相似性相同。在果蝇卵巢中表达显性负性 RhoL 转基因会导致滋养细胞塌陷并融合在一起。Cdc42 的突变形式模拟了这种效应。组成型活性 RhoL 的表达导致滋养细胞皮质下肌动蛋白分解以及滋养细胞与卵泡细胞接触的破坏，随后生殖细胞发生凋亡。相比之下，Rac 活性是一类称为边缘细胞的卵泡细胞亚群迁移所特需的。这三种活性对于滋养细胞细胞质正常转移到卵母细胞都是必需的。这些结果表明，Rho 蛋白活性对形态发生具有细胞类型特异性影响。
