P120 catenin represses transcriptional activity through Kaiso in endothelial cells

Jihang Zhang, James J. O'Donnell, Oksana Holian, Peter A. Vincent, Kwang S. Kim, Hazel Lum

Research output: Contribution to journalArticle

Abstract

P120 catenin (p120ctn) belongs to the family of Armadillo repeat-containing proteins, which are believed to have dual functions of cell-cell adhesion and transcriptional regulation. In vascular endothelium, p120ctn is mostly recognized for its cell-cell adhesion function through its ability to regulate VE-cadherin. The current study investigated whether p120ctn in endothelial cells also has the capability to signal transcription events. Examination of several endothelial cell types indicated that Kaiso, a p120ctn-binding transcription factor, was abundantly expressed, with a predominant localization to the perinuclear region. Immunoprecipitation of endothelial cell lysates with a p120ctn antibody resulted in p120ctn-Kaiso complex formation, confirming the interactions of the two proteins. Transfection of the KBS (Kaiso-binding sequence) luciferase reporter plasmid into endothelial cells resulted in a 40% lower reporter activity compared to the mutant Kaiso-insensitive construct or empty vector pGL3, indicating that the suppressed reporter activity was attributed to endogenous Kaiso. The knock-down of p120ctn increased the KBS reporter activity 2-fold over control, but had no effects on the mutant KBS reporter activity. Furthermore, p120ctn knock-down also reduced Kaiso expression, suggesting that p120ctn functioned to stabilize Kaiso. Overall, the findings provide evidence that in endothelial cells, p120ctn has a transcription repression function through regulation of Kaiso, possibly as a cofactor with the transcription factor.

Original languageEnglish (US)
Pages (from-to)233-239
Number of pages7
JournalMicrovascular Research
Volume80
Issue number2
DOIs
StatePublished - Sep 1 2010

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Keywords

  • Armadillo repeat-containing proteins
  • Endothelial cells
  • Kaiso
  • P120 catenin
  • Transcription repression
  • VE-cadherin

ASJC Scopus subject areas

  • Biochemistry
  • Cardiology and Cardiovascular Medicine
  • Cell Biology

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