The molecular mechanism of p160ROCK-mediated signaling pathway

我们发现rho相关的卷曲卷曲形成蛋白激酶（p160ROCK）是丝氨酸/苏氨酸激酶。p160ROCK是小GTPase Rho的效应蛋白成员，特异地与Rho的活化形式结合，从而在这种结合中被激活。在成纤维细胞和上皮细胞的转染实验中，该激酶参与了肌动蛋白应激纤维的形成和Rho介导的局灶粘连。此外，在成神经细胞N1E-115细胞中，该激酶通过调节细胞皮层的收缩力诱导细胞成圆。因此，人们认为p160ROCK定位于细胞中的几个特定位点，并使几种底物磷酸化。最近，我们开发了一种特异性的ROCK抑制剂，我们将其命名为Y-27632。这种化合物在激酶结构域与ATP竞争。利用该化合物，我们报道了Rho/ROCK通路调节高血压模型大鼠的血压，表明该通路参与了高血压的病理生理。然而，Rho/ROCK途径的分子机制尚不清楚。在本研究中，我们试图通过分离p160ROCK磷酸化底物来了解p160ROCK介导的信号通路的分子机制。因此，我们的主要发现如下：1。p160ROCK通过磷酸化和激活lim -kinase调控Confilin/ADF磷酸化。p160ROCK与Rho的另一效应分子media共同作用于Rho介导的肌动蛋白应力纤维形成和局灶粘连形成。

We found Rho-associated coiled coil forming protein kinase (p160ROCK) is serine/threonine kinase. p160ROCK is a member of effector protein of small GTPase Rho and specisically binds to activated form of Rho thereby becomes activated upon this binding. During transfction experiments in fibroblast and eptherial cells, this kinase is involved in formation of actin stress fibers and focal adhesions mediated by Rho. In addition to this, in nuroblastama N1E-115 cell this kinase induces cell rounding by regulating contractile force at cell cortex.Thus, it is thought that p160ROCK is localized to several specific sites in the cell and phosphorylates several substrates.Recently, we developed a specific inhibitor of ROCK, we named it Y-27632. This compound competes with ATP at the kinase domain. Using this compound, we reported that Rho/ROCK pathway regulates blood pressure in hypertension model rats, indicating that this pathway is involved in the pathophysiology of hypertension. However, the molecular mechanism of Rho/ROCK pathway is not clearly known.In this study, we try to understand the molecular mechanism (s) of p160ROCK-mediated signaling pathway (s) through the isolation of phosphorylated substrates for p160ROCK.As a result, our major findings are as follows,1. p160ROCK regulates Confilin/ADF phosphorylaytion through phosphorylation and activation of LIM-kinase.2. p160ROCK cooperates with mDia, another effector molecule of Rho, on Rho-mediated actin stress fiber formation and focal adhesion formation.