Bves modulates tight junction associated signaling

PLoS One. 2011 Jan 20;6(1):e14563. doi: 10.1371/journal.pone.0014563.

Abstract

Blood vessel epicardial substance (Bves) is a transmembrane adhesion protein that regulates tight junction (TJ) formation in a variety of epithelia. The role of TJs within epithelium extends beyond the mechanical properties. They have been shown to play a direct role in regulation of RhoA and ZONAB/DbpA, a y-box transcription factor. We hypothesize that Bves can modulate RhoA activation and ZONAB/DbpA activity through its regulatory effect on TJ formation. Immortalized human corneal epithelial (HCE) cells were stably transfected with Flag-tagged full length chicken Bves (w-Bves) or C-terminus truncated Bves (t-Bves). We found that stably transfected w-Bves and t-Bves were interacting with endogenous human Bves. However, interaction with t-Bves appeared to disrupt cell membrane localization of endogenous Bves and interaction with ZO-1. w-Bves cells exhibited increased TJ function reflected by increased trans-epithelial electrical resistance, while t-Bves cells lost TJ protein immunolocalization at cell-cell contacts and exhibited decreased trans-epithelial electrical resistance. In parental HCE and w-Bves cells ZONAB/DbpA and GEF-H1 were seen at cell borders in the same pattern as ZO-1. However, expression of t-Bves led to decreased membrane localization of both ZONAB/DbpA and GEF-H1. t-Bves cells had increased RhoA activity, as indicated by a significant 30% increase in FRET activity compared to parental HCE cells. ZONAB/DbpA transcriptional activity, assessed using a luciferase reporter probe, was increased in t-Bves cells. These studies demonstrate that Bves expression and localization can regulate RhoA and ZONAB/DbpA activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • CCAAT-Enhancer-Binding Proteins / metabolism
  • Cell Adhesion Molecules
  • Cell Line
  • Epithelial Cells
  • Epithelium, Corneal / cytology
  • Heat-Shock Proteins / metabolism
  • Humans
  • Membrane Proteins / physiology*
  • Muscle Proteins
  • Signal Transduction*
  • Tight Junctions / metabolism*
  • rhoA GTP-Binding Protein / metabolism

Substances

  • BVES protein, human
  • CCAAT-Enhancer-Binding Proteins
  • Cell Adhesion Molecules
  • Heat-Shock Proteins
  • Membrane Proteins
  • Muscle Proteins
  • YBX3 protein, human
  • rhoA GTP-Binding Protein