Interaction of Rho-kinase with myosin II at stress fibres
Interaction of Rho-kinase with myosin II at stress fibres
复制标题
DOI：
10.1111/j.1356-9597.2004.00749.x
复制
发表时间：
2004-07-01
期刊：
影响因子：
2.1
通讯作者：
Amano, M
中科院分区：
文献类型：
--
作者：
Kawabata, S;Usukura, J;Amano, M
Rho激酶和肌球蛋白磷酸酶协同调节肌球蛋白轻链的磷酸化水平，并参与应力纤维的形成和平滑肌收缩。已知Rho激酶定位于应力纤维，但对其定位机制知之甚少。在这里，我们确定了非肌肉肌球蛋白重链IIA和IIB的pleckstrin同源结构域相互作用分子的亲和柱层析。Rho-激酶的pleckstrin同源结构域在体外共沉降试验中直接与肌球蛋白II结合。普列克底物蛋白同源结构域的C-末端区域对于这种相互作用是重要的，并且普列克底物蛋白同源结构域突变体（W1170 A，W1340 L）中的点突变导致结合的降低。我们还发现，pleckstrin同源结构域，但不是pleckstrin同源结构域突变体（W1170 A，W1340 L），是本地化的应力纤维成纤维细胞。这些结果表明，Rho-激酶是本地化的应力纤维通过结合的普列克底物蛋白同源结构域的肌球蛋白II。
Rho-kinase and myosin phosphatase cooperatively regulate the phosphorylation level of myosin light chain and are involved in the formation of stress fibres and smooth muscle contraction. Rho-kinase has been known to be localized at stress fibres, but little is known about the mechanism of its localization. Here we identified non-muscle myosin heavy chain IIA and IIB as the pleckstrin homology domain-interacting molecules by affinity column chromatography. The pleckstrin homology domain of Rho-kinase binds to myosin II directly in in vitro cosedimentation assay. The C-terminal region of the pleckstrin homology domain was important for this interaction, and the point mutations in the pleckstrin homology domain mutant (W1170A, W1340L) resulted in a decrease in the binding. We also found that the pleckstrin homology domain, but not the pleckstrin homology domain mutant (W1170A, W1340L), was localized at stress fibres in fibroblasts. These results indicate that Rho-kinase is localized at stress fibres through binding of the pleckstrin homology domain to myosin II.