Reciprocal and dynamic polarization of planar cell polarity core components and myosin
Erin Newman-Smith,
Matthew J Kourakis,
Wendy Reeves,
Michael Veeman,
William C Smith
Affiliations
Erin Newman-Smith
Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
Matthew J Kourakis
Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
Wendy Reeves
Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States; Division of Biology, Kansas State University, Manhattan, United States
Michael Veeman
Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States; Division of Biology, Kansas State University, Manhattan, United States
William C Smith
Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
The Ciona notochord displays planar cell polarity (PCP), with anterior localization of Prickle (Pk) and Strabismus (Stbm). We report that a myosin is polarized anteriorly in these cells and strongly colocalizes with Stbm. Disruption of the actin/myosin machinery with cytochalasin or blebbistatin disrupts polarization of Pk and Stbm, but not of myosin complexes, suggesting a PCP-independent aspect of myosin localization. Wash out of cytochalasin restored Pk polarization, but not if done in the presence of blebbistatin, suggesting an active role for myosin in core PCP protein localization. On the other hand, in the pk mutant line, aimless, myosin polarization is disrupted in approximately one third of the cells, indicating a reciprocal action of core PCP signaling on myosin localization. Our results indicate a complex relationship between the actomyosin cytoskeleton and core PCP components in which myosin is not simply a downstream target of PCP signaling, but also required for PCP protein localization.
