Interaction of maize actin-depolymerising factor with actin and phosphoinositides and its inhibition of plant phospholipase C.
Interaction of maize actin-depolymerising factor with actin and phosphoinositides and its inhibition of plant phospholipase C.
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DOI：
10.1046/j.1365-313x.1998.00339.x
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发表时间：
1998-12-01
期刊：
影响因子：
7.2
通讯作者：
Hussey, PJ
中科院分区：
文献类型：
--
作者：
Gungabissoon, RA;Jiang, CJ;Hussey, PJ
我们以前曾报道分离的三个玉米基因编码肌动蛋白解聚因子/ cofilins，一个家庭的低分子量肌动蛋白调节蛋白。在本研究中，我们已经确定了这些蛋白质之一，ZmADF 3。我们报告说，ZmADF 3结合G-肌动蛋白与1：1的化学计量，并与F-肌动蛋白的相互作用是pH敏感的。ZmADF 3在pH 6.0时主要与F-肌动蛋白共沉淀，在pH 9.0时主要与G-肌动蛋白共沉淀。这种反应与脊椎动物cofilin和ADF的反应比与阿米巴actophorin的反应更相似，尽管阿米巴actophorin在一级序列上与ZmADF 3更相似，但其不是pH敏感性的。然而，ZmADF 3需要一个更基本的环境解聚肌动蛋白相对于脊椎动物ADF或cofilin。在低pH下用ZmADF 3装饰的细丝在升高pH时非常迅速地解聚，这与肌动蛋白细丝破坏的切断机制一致。此外，我们证明，ZmADF 3结合特定的聚磷脂酰肌醇脂质，特别是磷脂酰肌醇4，5-二磷酸（PIP 2），我们表明，这种结合抑制肌动蛋白解聚功能的ZmADF 3。此外，我们表明，ZmADF 3结合PIP 2的后果是抑制聚磷脂酰肌醇特异性植物磷脂酶C的活性，表明这一主要信号通路和肌动蛋白细胞骨架的相互调节的可能性。
We have previously reported the isolation of three Zea mays genes that encode actin-depolymerising factors/ cofilins, a family of low molecular weight actin regulating proteins. In the present study, we have characterised one of these proteins, ZmADF3. We report that ZmADF3 binds G-actin with a 1:1 stoichiometry, and that the interaction with F-actin is pH-sensitive. ZmADF3 co-sediments mainly with F-actin at pH 6.0 and mainly with G-actin at pH 9.0. This response is more similar to that of vertebrate cofilin and ADF than to that of Acanthamoeba actophorin which, although more similar in primary sequence to ZmADF3, is not pH sensitive. However, ZmADF3 requires a more basic environment to depolymerise actin relative to either vertebrate ADF or cofilin. Filaments decorated with ZmADF3 at low pH are very rapidly depolymerised upon raising the pH, which is consistent with a severing mechanism for the disruption of actin filaments. Also, we demonstrate that ZmADF3 binds specific polyphosphatidylinositol lipids, especially phosphatidylinositol 4,5-bisphosphate (PIP2), and we show that this binding inhibits the actin-depolymerising function of ZmADF3. Moreover, we show that a consequence of ZmADF3 binding PIP2 is the inhibition of the activity of polyphosphatidylinositol specific plant phospholipase C, indicating the possibility of reciprocal modulation of this major signalling pathway and the actin cytoskeleton.