Mentor
Kris DeMali
Participation year
2019
Abstract

Epithelial cells, which line the surfaces of the body, are exposed to a variety of forces. One main function of epithelial cells is to rapidly sense and respond to these forces. Failure to do so can result in illnesses such as cancer, cardiovascular disease, and diabetes. In epithelial cells, one mechanism in place to respond to these forces is through the cell surface adhesion receptor, epithelial cadherin (E-cadherin). E-Cadherin is located at intracellular junctions and acts as the primary adhesion molecule. In addition to the adhesive role of E-cadherin, it also mediates cells’ ability to withstand force by triggering a signaling cascade culminating in actin reinforcement and growth of the adhesion complex, known as cell stiffening. These processes are energetically costly. Recently, we have shown that force on cadherin stimulates glucose uptake and ATP production allowing cells to effectively stiffen. Preliminary data suggests that glucose transporter-1 (GLUT1) is the force-sensitive glucose transporter responsible for the force-induced glucose uptake. Interestingly, force on E-cadherin stimulates an enrichment of GLUT1 at  cell-cell junctions. However, how GLUT1 is retained at the membrane in response to the force on E-cadherin is  unknown. We propose that the application of force on E-cadherin stimulates retention of GLUT1 via a novel linkage between GLUT1 and E-cadherin mediated by the spectrin adaptor protein, Ankyrin G. The main function of Ankyrin G is to coordinate localization of many proteins to the plasma membrane. Previous studies have shown that E-cadherin directly binds to Ankyrin G but in this study we demonstrate that force stimulates an increase in Ankyrin G and E-cadherin binding as well as GLUT1 and ankyrin G association. In addition, we have begun to uncover a mechanism by which this occurs. Our data suggests that force triggers the release of p120 catenin from the cytoplasmic domain of E-cadherin, revealing the Ankyrin G binding site, allowing for an increase in Ankyrin G binding. 

Amanda Hernandez
Education
University of Puerto Rico-Rio Piedras