Lin Yiyan, Parajón Eleana, Yuan Qinling, Ye Siyu, Qin Guanghui, Deng Yu, Borleis Jane, Koyfman Ariel, Iglesias Pablo A, Konstantopoulos Konstantinos, Robinson Douglas N, Devreotes Peter N
Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD 21205.
Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD 21205.
Proc Natl Acad Sci U S A. 2025 Jul 29;122(30):e2503847122. doi: 10.1073/pnas.2503847122. Epub 2025 Jul 22.
Ras has traditionally been regarded as a positive regulator and therapeutic target due to its role in cell proliferation, but recent findings indicate a more nuanced role in cell migration, where suppressed Ras activity can unexpectedly promote migration. To clarify this complexity, we systematically modulate Ras activity using various RasGEF and RasGAP proteins and assess their effects on migration dynamics. Leveraging optogenetics, we assess the immediate, nontranscriptional effects of Ras signaling on migration. Local RasGEF recruitment to the plasma membrane induces protrusions and new fronts to effectively guide migration, even in the absence of GPCR/G-protein signaling, whereas global recruitment causes immediate cell spreading halting cell migration. Local RasGAP recruitment suppresses protrusions, generates new backs, and repels cells, whereas global relocation either eliminates all protrusions to inhibit migration or preserves a single protrusion to maintain polarity. Consistent local and global increases or decreases in signal transduction and cytoskeletal activities accompany these morphological changes. Additionally, we performed cortical tension measurements and found that Ras activity is regulated by guanine nucleotide exchange factors generally increase cortical tension while Ras activity is regulated by GTPase-activating proteins decrease it. Our results reveal a biphasic relationship between Ras activity and cellular dynamics, reinforcing our previous findings that optimal Ras activity and cortical tension are critical for efficient migration.
传统上，Ras因其在细胞增殖中的作用而被视为一种正向调节因子和治疗靶点，但最近的研究结果表明，它在细胞迁移中发挥着更为微妙的作用，其中Ras活性受到抑制时可能会意外地促进迁移。为了阐明这种复杂性，我们使用各种Ras鸟嘌呤核苷酸交换因子（RasGEF）和Ras GTP酶激活蛋白（RasGAP）系统地调节Ras活性，并评估它们对迁移动力学的影响。利用光遗传学，我们评估了Ras信号传导对迁移的即时、非转录效应。即使在没有G蛋白偶联受体（GPCR）/G蛋白信号传导的情况下，将局部RasGEF募集到质膜也会诱导突起和新的前沿，从而有效地引导迁移，而全局募集则会导致细胞立即铺展，从而阻止细胞迁移。局部募集RasGAP会抑制突起，产生新的后部，并排斥细胞，而全局重新定位要么消除所有突起以抑制迁移，要么保留单个突起以维持极性。这些形态变化伴随着信号转导和细胞骨架活性在局部和全局的一致增加或减少。此外，我们进行了皮质张力测量，发现一般来说，由鸟嘌呤核苷酸交换因子调节的Ras活性会增加皮质张力，而由GTP酶激活蛋白调节的Ras活性会降低皮质张力。我们的结果揭示了Ras活性与细胞动力学之间的双相关系，强化了我们之前的发现，即最佳的Ras活性和皮质张力对于有效迁移至关重要。
