Zaritsky Assaf, Tseng Yun-Yu, Rabadán M Angeles, Krishna Shefali, Overholtzer Michael, Danuser Gaudenz, Hall Alan
Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.
Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390.
J Cell Biol. 2017 Jun 5;216(6):1543-1556. doi: 10.1083/jcb.201609095. Epub 2017 May 16.
Efficient collective migration depends on a balance between contractility and cytoskeletal rearrangements, adhesion, and mechanical cell-cell communication, all controlled by GTPases of the RHO family. By comprehensive screening of guanine nucleotide exchange factors (GEFs) in human bronchial epithelial cell monolayers, we identified GEFs that are required for collective migration at large, such as SOS1 and β-PIX, and RHOA GEFs that are implicated in intercellular communication. Down-regulation of the latter GEFs differentially enhanced front-to-back propagation of guidance cues through the monolayer and was mirrored by down-regulation of RHOA expression and myosin II activity. Phenotype-based clustering of knockdown behaviors identified RHOA-ARHGEF18 and ARHGEF3-ARHGEF28-ARHGEF11 clusters, indicating that the latter may signal through other RHO-family GTPases. Indeed, knockdown of RHOC produced an intermediate between the two phenotypes. We conclude that for effective collective migration, the RHOA-GEFs → RHOA/C → actomyosin pathways must be optimally tuned to compromise between generation of motility forces and restriction of intercellular communication.
高效的集体迁移依赖于收缩性与细胞骨架重排、黏附以及机械性细胞间通讯之间的平衡，所有这些均受RHO家族的GTP酶调控。通过对人支气管上皮细胞单层中的鸟嘌呤核苷酸交换因子（GEF）进行全面筛选，我们鉴定出了集体迁移总体所需的GEF，如SOS1和β-PIX，以及与细胞间通讯有关的RHOA GEF。下调后者的GEF会不同程度地增强引导信号在单层细胞中从前向后的传播，这与RHOA表达下调和肌球蛋白II活性降低相对应。基于表型的敲低行为聚类鉴定出RHOA-ARHGEF18和ARHGEF3-ARHGEF28-ARHGEF11聚类，表明后者可能通过其他RHO家族GTP酶发出信号。事实上，敲低RHOC产生了介于两种表型之间的中间表型。我们得出结论，为实现有效的集体迁移，RHOA-GEFs→RHOA/C→肌动球蛋白途径必须进行最佳调节，以在产生运动力和限制细胞间通讯之间达成妥协。
