Biology

Dr. Anup Padmanabhan
Mechanobiology Institute, National University of Singapore

E-cadherin, by far the most well studied cell-cell adhesion receptor, is essential for epithelial tissue integrity, morphogenesis and development in all-multicellular organisms. Its functional disruption is associated with cancer metastasis. Our current understanding of the E-cadherin function is limited to its role as an adhesion receptor within cell-cell junctions despite the fact that clusters of E- cadherin have been observed at cell surfaces outside of junctions. What cellular roles, if any, may these non-junctional clusters have?

During the course of my analysis of the E-cadherin ortholog HMR-1 in early C. elegans development, I discovered that these non-junctional clusters slowed down cytokinetic furrow ingression. Intriguingly this inhibitory effect was independent of E-cadherin’s cell adhesion function and instead mediated by its cytoplasmic domain via two mechanisms – (1) E-cadherin/HMR-1 diminishes type-II myosin levels at the cell cortex by inhibiting RHO activity, and (2) by physically associating with the cortical F-actin, E-cadherin/HMR-1 resists cortical shape changes such as during cytokinesis.

I will discuss these recent findings that led to the discovery of adhesion- independent role of E-cadherin in regulating the actomyosin cortex.