Rap1 Negatively Regulates the Hippo Pathway to Polarize Directional Protrusions in Collective Cell Migration.
In collective cell migration, directional protrusions orient cells in response to external cues, which requires coordinated polarity among the migrating cohort. However, the molecular mechanism has not been well defined. Drosophila border cells (BCs) migrate collectively and invade via the confined space between nurse cells, offering an in vivo model to examine how group polarity is organized. Here, we show that the front/back polarity of BCs requires Rap1, hyperactivation of which disrupts cluster polarity and induces misoriented protrusions and loss of asymmetry in the actin network. Conversely, hypoactive Rap1 causes fewer protrusions and cluster spinning during migration. A forward genetic screen revealed that downregulation of the Hippo (Hpo) pathway core components hpo or mats enhances the Rap1V12-induced migration defect and misdirected protrusions. Mechanistically, association of Rap1V12 with the kinase domain of Hpo suppresses its activity, which releases Hpo signaling-mediated suppression of F-actin elongation, promoting cellular protrusions in collective cell migration.
['Chang|Yu-Chiuan|YC|', 'Wu|Jhen-Wei|JW|', 'Hsieh|Yi-Chi|YC|', 'Huang|Tzu-Han|TH|', 'Liao|Zih-Min|ZM|', 'Huang|Yi-Shan|YS|', 'Mondo|James A|JA|', 'Montell|Denise|D|', 'Jang|Anna C-C|AC|']
D000205:Actomyosin D000818:Animals D002465:Cell Movement D016764:Cell Polarity D022081:Cell Surface Extensions D029721:Drosophila Proteins D004331:Drosophila melanogaster D004843:Epistasis, Genetic D047908:Intracellular Signaling Peptides and Proteins D008954:Models, Biological D017346:Protein Serine-Threonine Kinases D000089804:Shelterin Complex D015398:Signal Transduction D034501:Telomere-Binding Proteins
Rap1 Border cells group polarity Hippo signaling