ROCK activation by RHO

ROCKs are primarily known as downstream effectors of RHO, but they can also be activated by arachidonic acid, which binds to the pleckstrin homology domain, releasing an autoinhibitory loop within ROCK and allowing catalytic activity (Araki et al. 2001). Proteolytic cleavage at the C-terminus by caspase-3 and granzyme B also activates ROCK1 and ROCK2, causing plasma membrane blebbing during apoptosis (Coleman et al. 2001, Sebbagh et al. 2005). Multiple targets of ROCK contribute to the stabilization of actin filaments and the generation of actin-myosin contractile force.

ROCKs（RHO下游效应器）主要为人所熟知，然而，它们亦可通过与花生四烯酸结合并作用于磷脂酰肌醇同源结构域，从而激活ROCK，解除ROCK内部的自抑制环，并允许其催化活性（Araki等，2001年）。由caspase-3和granzyme B在C端进行的蛋白水解切割亦能激活ROCK1和ROCK2，导致细胞膜在凋亡过程中的泡状突起（Coleman等，2001年，Sebbagh等，2005年）。ROCK的多个靶点共同作用于稳定肌动蛋白丝和产生肌动蛋白-肌球蛋白收缩力。