1. Rap1 Negatively Regulates the Hippo Pathway to Polarize Directional Protrusions in Collective Cell Migration
- Author
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Zih Min Liao, Yu Chiuan Chang, Denise J. Montell, Jhen Wei Wu, Anna C.C. Jang, James A. Mondo, Yi Shan Huang, Tzu Han Huang, and Yi Chi Hsieh
- Subjects
0301 basic medicine ,endocrine system ,Polarity (physics) ,Telomere-Binding Proteins ,Protein Serine-Threonine Kinases ,Models, Biological ,General Biochemistry, Genetics and Molecular Biology ,Shelterin Complex ,Article ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,Cell Movement ,Border cells ,Animals ,Drosophila Proteins ,lcsh:QH301-705.5 ,Actin ,Hippo signaling pathway ,Rap1 ,Chemistry ,Hippo signaling ,Intracellular Signaling Peptides and Proteins ,Cell Polarity ,Epistasis, Genetic ,Actomyosin ,group polarity ,Cell biology ,030104 developmental biology ,Drosophila melanogaster ,Protein kinase domain ,lcsh:Biology (General) ,Cell Surface Extensions ,030217 neurology & neurosurgery ,Genetic screen ,Signal Transduction - Abstract
Summary 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 Rap1 V12 -induced migration defect and misdirected protrusions. Mechanistically, association of Rap1 V12 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.
- Published
- 2017