Bves modulates epithelial integrity through an interaction at the tight junction.
We first identified Bves (blood vessel/epicardial substance) as a transmembrane protein that localized to the lateral compartment of the epithelial epicardium. Bves traffics to sites of cell-cell contact in cultured epicardial cells and promotes adhesion following transfection into non-adherent fibroblastic L-cells, reminiscent of a cell adhesion molecule. Currently, no function for Bves in relation to epithelial cell adhesion has been identified. We hypothesize that Bves plays a role at cell junctions to establish and/or modulate cell adhesion or cell-cell interactions in epithelial cell types. In this study, we demonstrate that Bves regulates epithelial integrity and that this function may be associated with a role at the tight junction (TJ). We report that Bves localizes with ZO-1 and occludin, markers of the TJ, in polarized epithelial cell lines and in vivo. We find that the behavior of Bves following low Ca2+ challenge or TPA treatment mimics that observed for ZO-1 and is distinct from adherens junction proteins such as E-cadherin. Furthermore, GST pull-down experiments show an interaction between ZO-1 and the intracellular C-terminal tail of Bves. Finally, we demonstrate that Bves modulates tight junction integrity, as indicated by the loss of transepithelial resistance and junction protein localization at the membrane following Bves knock-down in cultured cells. This study is the first to identify a function for Bves in epithelia and supports the hypothesis that Bves contributes to establishment and/or maintenance of epithelial cell integrity.
Osler
Megan E
ME
Stahlman Cardiovascular Laboratories, Program for Developmental Biology, Division of Cardiovascular Medicine, Vanderbilt University, 222 Pierce Avenue, Nashville, TN 37232-6300, USA.
Chang
Min S
MS
Bader
David M
DM
D000818:Animals; D030161:Avian Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D009124:Muscle Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D016296:Mutagenesis; D062793:Occludin; D010703:Phorbol Esters / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding; D019108:Tight Junctions / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein
D030161:Avian Proteins; C498788:Bves protein, Gallus gallus; D015820:Cadherins; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D009124:Muscle Proteins; C568985:OCLN protein, human; D062793:Occludin; D010703:Phorbol Esters; D010750:Phosphoproteins; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; D002118:Calcium