Characterizing the Role of RhoGAP19D in Drosophila Epithelial Development

The establishment and maintenance of epithelial polarity is dependent on polarity regulators. One such polarity regulatory is Bazooka (Baz). Baz is located around the apical circumference, serving as a cytosplasmic scaffold to assemble adherens junctions. In vitro analyses presented RhoGAP19D as a potential Baz-interacting protein. RhoGAP19D’s homologs have been linked to the actin cytoskeleton and the PAR complex through the RhoGTPase CDC42. To study RhoGAP19D’s functions, a GFP-tagged RhoGAP19D was made. This construct was expressed in the Drosophila embryonic ectoderm and follicular epithelium. It localized to the apical circumference with enrichment at Baz-puncta and actin-rich locations, but its main localization mechanism appears to be independent of Baz. Gain-of-function and loss-of-function analyses for RhoGAP19D revealed phenotypes consistent with it being an inhibitor of the PAR complex and the actin cytoskeleton. Thus, I hypothesize that RhoGAP19D regulates Drosophila epithelial polarity by inhibiting the PAR complex and the actin cytoskeleton by inhibiting CDC42.MAS