Aurora-A interacts with AP-2α and down regulates its transcription activity

PLoS One. 2011;6(8):e23110. doi: 10.1371/journal.pone.0023110. Epub 2011 Aug 1.

Abstract

Aurora-A is a serine/threonine protein kinase and plays an important role in the control of mitotic progression. Dysregulated expression of Aurora-A impairs centrosome separation and maturation, which lead to disrupted cell cycle progression and tumorigenesis. However, the molecular mechanism by which Aurora-A causes cell malignant transformation remains to be further defined. In this report, using transcription factors array and mRNA expression profiling array, we found that overexpression of Aurora-A suppressed transcription activity of AP-2α, a tumor suppressor that is often downregulated in variety of tumors, and inhibited expression of AP-2α-regulated downstream genes. These array-based observations were further confirmed by microwell colorimetric TF assay and luciferase reporter assay. Downregulated transcription activity of AP-2α by Aurora-A was found to be associated with reduced AP-2α protein stability, which appeared to be mediated by Aurora-A enhanced ubiquitin-dependent proteasomal degradation of AP-2α protein. Interestingly, Aurora-A-mediated AP-2α degradation was likely dependent Aurora-A kinase activity since inhibition of Aurora-A kinase activity was able to rescue Aurora-A-induced degradation of AP-2α. Moreover, we defined a physical interaction between Aurora-A and AP-2α, and such interaction might bridge the suppressive effect of Aurora-A on AP-2α protein stability. These findings provide new insights into molecular mechanism by which Aurora-A acts as an oncogenic molecule in tumor occurrence and malignant development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aurora Kinases
  • Blotting, Western
  • Cell Cycle
  • Cell Line
  • Down-Regulation / physiology*
  • Enzyme-Linked Immunosorbent Assay
  • Gene Expression Profiling
  • Humans
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Serine-Threonine Kinases / metabolism*
  • Transcription Factor AP-2 / metabolism*
  • Transcription Factor AP-2 / physiology
  • Transcription, Genetic / physiology*

Substances

  • Transcription Factor AP-2
  • Aurora Kinases
  • Protein Serine-Threonine Kinases
  • Proteasome Endopeptidase Complex