Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
Sci Rep. 2021 Jan 27;11(1):2348. doi: 10.1038/s41598-021-82027-4.
Actin-dependent mechanisms drive the nuclear translocation of Yap1 to enable its co-activation of transcription factors that induce pro-growth and survival programs. While Rho GTPases are necessary for the nuclear import of YAP1, the relevant Guanine Exchange Factors (GEFs) and GTPase Activating Proteins (GAPs) that connect this process to upstream signaling are not well defined. To this end, we measured the impact of expressing sixty-seven RhoGEFs and RhoGAPs on the YAP1 dependent activity of a TEAD element transcriptional reporter. Robust effects by all three members of the regulator of G-protein signaling (RGS) domain containing RhoGEFs (ArhGEF1, ArhGEF11 and ArhGEF12) prompted studies relating their known roles in serum signaling onto the regulation of Yap1. Under all conditions examined, ArhGEF12 preferentially mediated the activation of YAP1/TEAD by serum versus ArhGEF1 or ArhGEF11. Conversely, ArhGEF1 in multiple contexts inhibited both basal and serum elevated YAP1 activity through its GAP activity for Gα. The sensitivity of such inhibition to cellular density and to low states of serum signaling supports that ArhGEF1 is a context dependent regulator of YAP1. Taken together, the relative activities of the RGS-RhoGEFs were found to dictate the degree to which serum signaling promotes YAP1 activity.
依赖肌动蛋白的机制驱动 Yap1 的核易位，使其能够共同激活诱导促生长和存活程序的转录因子。虽然 Rho GTPases 是 YAP1 核输入所必需的，但将此过程与上游信号连接起来的相关鸟嘌呤核苷酸交换因子 (GEFs) 和 GTPase 激活蛋白 (GAPs) 尚未得到很好的定义。为此，我们测量了表达六十七种 RhoGEFs 和 RhoGAPs 对 YAP1 依赖性 TEAD 元件转录报告基因活性的影响。调节 G 蛋白信号的三个 RGS 结构域蛋白 (ArhGEF1、ArhGEF11 和 ArhGEF12) 均对该过程产生了显著影响，促使人们将其已知的在血清信号中的作用与 Yap1 的调节联系起来。在所有检查的条件下，ArhGEF12 优先介导血清而非 ArhGEF1 或 ArhGEF11 对 YAP1/TEAD 的激活。相反，在多种情况下，ArhGEF1 通过其 Gα 的 GAP 活性抑制基础和血清升高的 YAP1 活性。这种抑制对细胞密度和低血清信号状态的敏感性支持了 ArhGEF1 是 YAP1 的一种依赖于上下文的调节剂。总之，RGS-RhoGEFs 的相对活性决定了血清信号促进 YAP1 活性的程度。
