The ability of epithelial cells to change shape is essential to the patterning of tissues and organs during development of the vertebrate embryo. Epithelial morphogenesis is mediated by the molecular regulation of cytoskeletal dynamics which underlies cellular adhesion, motility, polarity, and proliferation. The Shroom family of proteins regulates epithelial morphogenesis by promoting MyosinII-dependent changes in epithelial morphology through the ability to bind both F-actin and Rho kinase (Rock). Shroom3 is necessary to induce apical constriction of the neural epithelium and is required for proper neural tube closure during development. However, the roles of other family members are unknown. This work seeks to determine the role and mechanism of action for Shroom2 in epithelial cell biology.

Through RNAi, the loss of Shroom2 reduces contractility of endothelial cells. Shroom2 physically interacts with Rock and is necessary for its cortical localization. By impeding Rock localization and reducing contractility, Shroom2 knockdown alters cytoskeletal organization, adhesion, and motility which ultimately affects in vitro angiogenesis. During these studies, it also became clear that Shroom2 localizes to the centrosome where it is required to maintain efficient centrosome duplication in a Rock-dependent manner. The results described here expand a role for the Shroom proteins in the sub-cellular localization of Rock which mediates a subset of Rock functions within epithelial cells.