Actomyosin-based contractility in smooth muscle and nonmuscle cells is regulated by signaling through the small GTPase Rho and by calcium-activated pathways. We use the myoepithelial cells of the Caenorhabditis elegans spermatheca to study the mechanisms of coordinated myosin activation in vivo. Here, we show that redox signaling modulates RHO-1/Rho activity in this contractile tissue. Exogenously added as well as endogenously generated hydrogen peroxide decreases spermathecal contractility by inhibition of RHO-1, which depends on a conserved cysteine in its nucleotide binding site (C20). Further, we identify an endogenous gradient of H 2 O 2 across the spermathecal tissue, which depends on the activity of cytosolic superoxide dismutase, SOD-1. Collectively, we show that SOD-1-mediated H 2 O 2 production regulates the redox environment and fine tunes Rho activity across the spermatheca through oxidation of RHO-1 C20.
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机译:通过通过小GTPA酶rhO和钙激活的途径来调节平滑肌和非气球细胞中的基于肌动素的合成性。我们使用Caenorhabditisegans Spermatheca的肌肌肌肌上细胞来研究体内协调肌蛋白激活的机制。在这里,我们表明氧化还原信号传导调节该收缩组织中的ROO-1 / RHO活性。外源添加以及内源产生的过氧化氢通过抑制RHO-1来降低精子收缩性,这取决于其核苷酸结合位点(C20)中的保守半胱氨酸。此外,我们将H 2 O 2的内源性梯度识别在精子组织上,这取决于细胞溶质超氧化物歧化酶的活性,SOD-1。总的来说,我们表明SOD-1介导的H 2 O 2生产通过rhO-1 C20的氧化来调节氧化还原环境和微调rho活性。
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