"Dialogue between Cell Adhesion and the Cytoskeleton in Morphogenesis"

Dr. Nick Brown
The Gurdon Institute and Dept of Physiology, Development & Neuroscience, University of Cambridge, UK
Friday, April 11, 2014 - 2:00pm
Ramsay Wright Building, Room 432
Departmental Seminar
A key part of cell adhesion is the link between the transmembrane adhesion receptors and the cytoskeleton. Adhesion receptors nucleate and organise the cytoskeleton to mediate changes in cell shape and provide sufficient resistance to mechanical force. In turn, the cytoskeleton regulates the local accumulation and function of adhesion receptors. We use the model organism Drosophila to study the adhesion/cytoskeleton dialogue within intact developing animals, using a combination of genetics and imaging. Our recent work on three aspects of this problem will be discussed. We found that the E-cadherin within adherens junctions is in two distinct pools; a stable pool and a novel dynamic pool associated with Par-3. The E-cad/Par-3 complex is regulated by dynamic microtubules and functions to control cell mobility within epithelial sheets. Turning to integrin adhesions, we found that the key linker protein talin functions differently in alternative developmental contexts, forming unique interactions and adopting perpendicular or parallel orientations relative to the membrane, revealed by a combination of genetics and advanced imaging. Finally, we show by activating the linker protein vinculin, we can bypass the need for integrin to initiate the aggregation of talin and other linker proteins into focal adhesion-like structures.
Prof. Ulrich Tepass <u.tepass@utoronto.ca>
Dept of Cell and Systems Biology