Identification of a novel, putative Rho-specific GDP/GTP exchange factor and a RhoA-binding protein: Control of neuronal morphology
Identification of a novel, putative Rho-specific GDP/GTP exchange factor and a RhoA-binding protein: Control of neuronal morphology
复制标题
DOI：
10.1083/jcb.137.7.1603
复制
发表时间：
1997-06-30
影响因子：
7.8
通讯作者：
Moolenaar, WH
中科院分区：
文献类型：
--
作者：
Gebbink, MFBG;Kranenburg, O;Moolenaar, WH
小 GTP 结合蛋白 Rho 与神经元形态的控制有关。在 N1E-115 神经元细胞中，Rho 失活 C3 毒素会刺激神经突生长，并防止溶血磷脂酸 (LPA)、1-磷酸鞘氨醇或凝血酶作用于其同源 G 蛋白偶联受体而诱导的基于肌动球蛋白的神经突收缩和细胞变圆。我们已经确定了一种新的假定 GDP/GTP 交换因子 RhoGEF (190 kD)，它与野生型和活化的 RhoA 相互作用，但不与 Rac 或 Cdc42 相互作用。 RhoGEF 与激活的 RhoA 一样，模仿受体刺激来诱导细胞变圆和防止神经突生长。此外，我们还鉴定了一种 116 kD 蛋白 p116(Rip)，它与 N1E-115 细胞中 RhoA 的 GDP 结合形式和 GTP 结合形式相互作用。 p116(Rip) 的过度表达会刺激细胞扁平化和神经突生长，其方式与显性失活 RhoA 和 C3 毒素类似。正如 Rho 失活后所观察到的那样，过表达 p116(Rip) 的细胞无法响应 LPA 改变其形状。我们的结果表明 (a) RhoGEF 可能将 G 蛋白偶联受体与 RhoA 激活以及随后的神经突收缩和细胞变圆联系起来； (b) p116(Rip) 抑制 RhoA 刺激的收缩性并促进神经突生长。
The small GTP-binding protein Rho has been implicated in the control of neuronal morphology. In N1E-115 neuronal cells, the Rho-inactivating C3 toxin stimulates neurite outgrowth and prevents actomyosin-based neurite retraction and cell rounding induced by lysophosphatidic acid (LPA), sphingosine-1-phosphate, or thrombin acting on their cognate G protein-coupled receptors. We have identified a novel putative GDP/GTP exchange factor, RhoGEF (190 kD), that interacts with both wild-type and activated RhoA, but not with Rac or Cdc42. RhoGEF, like activated RhoA, mimics receptor stimulation in inducing cell rounding and in preventing neurite outgrowth. Furthermore, we have identified a 116-kD protein, p116(Rip), that interacts with both the GDP- and GTP-bound forms of RhoA in N1E-115 cells. Overexpression of p116(Rip) stimulates cell flattening and neurite outgrowth in a similar way to dominant-negative RhoA and C3 toxin. Cells overexpressing p116(Rip) fail to change their shape in response to LPA, as is observed after Rho inactivation. Our results indicate that (a) RhoGEF may link G protein-coupled receptors to RhoA activation and ensuing neurite retraction and cell rounding; and (b) p116(Rip) inhibits RhoA-stimulated contractility and promotes neurite outgrowth.