9.B.455. The Drosophila Diamond functioning with Dynactin/Dynein (DDDD) Family
Epithelial polarity is critical for proper functions of epithelial tissues, tumorigenesis, and metastasis. The evolutionarily conserved transmembrane protein Crumbs (Crb; TC# 9.B.87.1.11) is a key regulator of epithelial polarity. Both Crb protein and its transcripts are apically localized in epithelial cells. Using Drosophila ovarian follicular epithelia as a model, Zhao et al. 2023 showed that epithelial polarity is lost and the Crb protein is absent in the apical domain in follicular cells (FCs) in the absence of Diamond (Dind). Dind is found to associate with different components of the dynactin-dynein complex through co-IP-MS analysis. Dind stabilizes dynactin and depletion of dynactin results in almost identical defects as those observed in Dind-defective FCs. Both Dind and dynactin are also required for the apical localization of crb transcripts in FCs. Thus, Dind functions through dynactin/dynein-mediated transport of both the Crb protein and its transcripts to the apical domain to control epithelial apico-basal (A/B) polarity (Zhao et al. 2023).