Dynamic myosin phosphorylation regulates contractile pulses and tissue integrity during epithelial morphogenesis
Author(s)Vasquez, Claudia G.; Tworoger, Michael B.; Martin, Adam C.
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Apical constriction is a cell shape change that promotes epithelial bending. Activation of nonmuscle myosin II (Myo-II) by kinases such as Rho-associated kinase (Rok) is important to generate contractile force during apical constriction. Cycles of Myo-II assembly and disassembly, or pulses, are associated with apical constriction during Drosophila melanogaster gastrulation. It is not understood whether Myo-II phosphoregulation organizes contractile pulses or whether pulses are important for tissue morphogenesis. Here, we show that Myo-II pulses are associated with pulses of apical Rok. Mutants that mimic Myo-II light chain phosphorylation or depletion of myosin phosphatase inhibit Myo-II contractile pulses, disrupting both actomyosin coalescence into apical foci and cycles of Myo-II assembly/disassembly. Thus, coupling dynamic Myo-II phosphorylation to upstream signals organizes contractile Myo-II pulses in both space and time. Mutants that mimic Myo-II phosphorylation undergo continuous, rather than incremental, apical constriction. These mutants fail to maintain intercellular actomyosin network connections during tissue invagination, suggesting that Myo-II pulses are required for tissue integrity during morphogenesis.
DepartmentMassachusetts Institute of Technology. Department of Biology
Journal of Cell Biology
Rockefeller University Press
Vasquez, C. G., M. Tworoger, and A. C. Martin. “Dynamic Myosin Phosphorylation Regulates Contractile Pulses and Tissue Integrity During Epithelial Morphogenesis.” The Journal of Cell Biology 206, no. 3 (August 4, 2014): 435–450.
Final published version