"Maintenance and remodeling of cell-cell junctions in dynamic epithelia”

The Miller lab investigates questions about cytokinesis, cell-cell junction dynamics, and epithelial tissue mechanics. We are focused on how adhesion and barrier function are maintained and remodeled during cell shape change events such as cytokinesis. We have identified mechanisms that allow cell-cell junctions to be stable enough to promote cell-cell adhesion and barrier function, but plastic enough to remodel when necessary. We have revealed new information about how Rho GTPase activity is regulated in space and time and how RhoA orchestrates the actin cytoskeletal dynamics responsible for cytokinesis and cell-cell junction remodeling. Additionally, we have characterized novel roles for key regulators of these processes including Anillin, MgcRacGAP, and Vinculin. We use Xenopus laevis as a vertebrate model organism because Xenopus embryos form beautifully polarized cell-cell junctions that are well-suited for live imaging of junctions and cytoskeletal dynamics. We have developed a molecular toolkit and techniques for investigating localized dynamics of active Rho GTPases, cell-cell junction proteins, and the cytoskeleton as well as a novel, sensitive live imaging barrier assay. In my talk, I will discuss some of our recent findings about how epithelial cells maintain and remodel their tight junctions and adherens junctions when cell-cell junctions elongate and when cells divide.