Adherens junctions (AJs) are key regulators of intercellular adhesion and thus play an important role in the self-assembly of cells into complex tissues. The balance between AJ assembly and disassembly is likely to be regulated during mophogenesis. Studies in mammalian cells suggest that the intracellular trafficking of AJs modulates adhesion; however, the regulation of this process during normal development and tissue homeostasis is largely unknown. We hypothesize that AJ remodeling is tightly coupled to morphogenesis and tissue maintenance via the directed trafficking of AJ components. Furthermore, I hypothesize that AJs are modified and reassembled during mitosis by regulated interactions with the cytoskeleton. I will investigate the mechanism of the intracellular transport of AJ proteins in Drosophila embryos. I will mutagenize the DE-cadherin cytoplasmic domain to determine regions that affect AJ cell surface stability. I will define potential regulators of AJ endocytosis, and I will examine the putative role of microtubules and motor proteins in AJ transport. Finally, I will use the information gained from these studies to formulate and test models of coordinated AJ remodeling during mitosis and embryonic development. ? ? ?
