The junctional proteins cingulin and paracingulin modulate the expression of tight junction protein genes through GATA-4

PLoS One. 2013;8(2):e55873. doi: 10.1371/journal.pone.0055873. Epub 2013 Feb 7.

Abstract

The cytoplamic junctional proteins cingulin and paracingulin have been implicated in the regulation of gene expression in different cultured cell models. In renal epithelial MDCK cells, depletion of either protein results in a Rho-dependent increase in the expression of claudin-2. Here we examined MDCK cell clones depleted of both cingulin and paracingulin (double-KD cells), and we found that unexpectedly the expression of claudin-2, and also the expression of ZO-3 and claudin-3, were decreased, while RhoA activity was still higher than in control cells. The decreased expression of claudin-2 and other TJ proteins in double-KD cells correlated with reduced levels of the transcription factor GATA-4, and was rescued by overexpression of GATA-4, but not by inhibiting RhoA activity. These results indicate that in MDCK cells GATA-4 is required for the expression of claudin-2 and other TJ proteins, and that maintenance of GATA-4 expression requires either cingulin or paracingulin. These results and previous studies suggest a model whereby cingulin and paracingulin redundantly control the expression of specific TJ proteins through distinct GATA-4- and RhoA-dependent mechanisms, and that in the absence of sufficient levels of GATA-4 the RhoA-mediated upregulation of claudin-2 is inhibited.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Claudin-2 / genetics
  • Claudin-2 / metabolism
  • Claudin-3 / genetics
  • Claudin-3 / metabolism
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • GATA4 Transcription Factor / metabolism*
  • Gene Expression Regulation*
  • Gene Knockdown Techniques
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Phenotype
  • Tight Junction Proteins / genetics*
  • Zonula Occludens Proteins / genetics
  • Zonula Occludens Proteins / metabolism
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Claudin-2
  • Claudin-3
  • Cytoskeletal Proteins
  • GATA4 Transcription Factor
  • Membrane Proteins
  • Tight Junction Proteins
  • Zonula Occludens Proteins
  • rhoA GTP-Binding Protein

Grant support

This study was funded by the Swiss National Science Foundation (grants n. 31003A103637, 31003A116763), the State of Geneva, and the Section of Biology of the University of Geneva. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.