Luo J Q, Liu X, Hammond S M, Colley W C, Feig L A, Frohman M A, Morris A J, Foster D A
Department of Biological Sciences, Hunter College of The City University of New York, New York 10021, USA.
Biochem Biophys Res Commun. 1997 Jun 27;235(3):854-9. doi: 10.1006/bbrc.1997.6793.
RalA GTPase associates with a phospholipase D (PLD) that is activated in v-Src- and v-Ras-transformed cells. Two mammalian PLDs were recently cloned: PLD1, which is activated by Arf family GTPases and dependent upon phosphatidylinositol-4,5-bisphosphate (PIP2), and PLD2, which is also dependent upon PIP2, but not stimulated by Arf. Another PLD has been described that is stimulated by oleate. Evidence is provided that the RalA-assiciated PLD is PLD1. First, the PLD precipitated by RalA from murine fibroblasts was stimulated by Arf, dependent upon PIP2, and inhibited by oleate. Second, immobilized RalA precipitated PLD1 from sf9 insect cells overexpressing PLD1. Third, a series of RalA mutants precipitated PLD activity from both PLD1-expressing insect cells and murine fibroblasts with the same efficiency. And finally, immobilized RalA precipitated PLD1 from a purified PLD1 preparation. These data argue that RalA associates directly with the Arf-responsive, PIP2-dependent PLD1.
RalA GTP酶与一种磷脂酶D（PLD）相关联，该磷脂酶D在v-Src和v-Ras转化的细胞中被激活。最近克隆出了两种哺乳动物PLD：PLD1，它由Arf家族GTP酶激活并依赖于磷脂酰肌醇-4,5-二磷酸（PIP2）；以及PLD2，它也依赖于PIP2，但不受Arf刺激。还描述了另一种受油酸刺激的PLD。有证据表明与RalA相关的PLD是PLD1。首先，RalA从鼠成纤维细胞中沉淀出的PLD受Arf刺激，依赖于PIP2，并被油酸抑制。其次，固定化的RalA从过表达PLD1的sf9昆虫细胞中沉淀出PLD1。第三，一系列RalA突变体以相同效率从表达PLD1的昆虫细胞和鼠成纤维细胞中沉淀出PLD活性。最后，固定化的RalA从纯化的PLD1制剂中沉淀出PLD1。这些数据表明RalA直接与Arf反应性、PIP2依赖性的PLD1相关联。
Zotero 插件