Blood vessel/epicardial substance – Bves – was identified in 1999 as a heart-enriched gene product. Since then, although there have been hints that it may be a cell-adhesion molecule, its function in epithelial cells has remained undefined. David Bader and colleagues now remedy this by reporting that Bves modulates epithelial cell integrity by helping to establish and/or maintain tight junctions (see ). In vivo, epithelial cells form contiguous sheets of cells that are held together by tight junctions and other cellular junctions. Bader and colleagues use confocal and electron microscopy to show that Bves localizes with the tight junction markers ZO-1 and occludin in epithelial cell lines and in vivo. They also report that Bves behaves similarly to ZO-1 after physiological stimuli that alter cell adhesion and show that Bves interacts with ZO-1. Finally, by using a knockdown approach, the authors reveal that Bves modulates tight junction integrity. Thus, they propose, Bves is a junctional cell-adhesion molecule that helps to maintain epithelial cell integrity.
