Investigation of the novel activation mechanism of MRTF, a master transcriptional regulator of the actin cytoskeleton.

在这项研究中，我研究了myocardin家族蛋白、myocardin和MRTF的新的激活机制。肌动蛋白的相互作用抑制了MRTF的活性。我发现Tb4蛋白是MRTF/肌动蛋白相互作用的抑制因子。Myocardin也与肌动蛋白相互作用，但其对肌动蛋白的亲和力相当低。我证明了肌动蛋白相关蛋白5(Arp5)，而不是肌动蛋白，与肌钙蛋白紧密结合并抑制其活性。在平滑肌细胞中，Arp5的表达水平很低，导致了Myocardin的高活性。

In this study, I investigated the novel activation mechanism of myocardin family proteins, myocardin and MRTF. The activity of MRTF is suppressed by interaction with actin. I identified Tb4 protein as an inhibitory factor of MRTF/actin interaction. myocardin also interacts with actin, but its affinity for actin is rather low. I demonstrated that actin-related protein 5 (Arp5), instead of actin, tightly bound to myocardin and suppressed its activity. In smooth muscle cells, Arp5 expression level is very low, resulting in high activity of myocardin.