@article {Zaritsky076125, author = {Assaf Zaritsky and Yun-Yu Tseng and M. Angeles Rabadan and Shefali Krishna and Michael Overholtzer and Gaudenz Danuser and Alan Hall}, title = {Diverse roles of guanine nucleotide exchange factors in regulating collective cell migration}, elocation-id = {076125}, year = {2017}, doi = {10.1101/076125}, publisher = {Cold Spring Harbor Laboratory}, abstract = {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. Downregulation of the latter GEFs differentially enhanced front-to-back propagation of guidance cues through the monolayer, and was mirrored by downregulation of RHOA expression and myosin-II activity. Phenotype-based clustering of knock-down behaviors identified RHOA-ARHGEF18 and ARHGEF3-ARHGEF28-ARHGEF11 clusters, indicating that the latter may signal through other RHO-family GTPases. Indeed, knock-down of RHOC produced an intermediate between the two phenotypes. We conclude that for effective collective migration the RHOA-GEFs-{\textrightarrow}ARHOA/C{\textrightarrow} actomyosin pathways must be optimally tuned to compromise between generation of motility forces and restriction of intercellular communication.GEFguanine nucleotide exchange factorsGDIguanine dissociation inhibitors16HBEhuman bronchial epithelial cells from the 16HBE14o linePCAprincipal component analysisPCprincipal componentsshRNAsmall hairpin RNAKDknockdownFBSfetal bovine serumPCRpolymerase chain reactionqRT-PCRquantitative real time PCRROIregion of interest}, URL = {https://www.biorxiv.org/content/early/2017/03/14/076125}, eprint = {https://www.biorxiv.org/content/early/2017/03/14/076125.full.pdf}, journal = {bioRxiv} }