The DEAD Box Protein Ddx42p Modulates the Function of ASPP2, a Stimulator of Apoptosis

Oncogene. 2009 May 21;28(20):2065-73. doi: 10.1038/onc.2009.75. Epub 2009 Apr 20.

Abstract

Ddx42p is a recently characterized mammalian DEAD box protein with unknown cellular function. We found that in human cells Ddx42p physically interacts with ASPP2, a major apoptosis inducer known to enhance p53 transactivation of proapoptotic genes. The proteins interact via a domain within the carboxy-terminal part of Ddx42p and a mid-amino-terminal sequence as well as the ankyrin-SH3 region of ASPP2. Overexpression of Ddx42p interferes with apoptosis induction by ASPP2, whereas Ddx42p knockdown reduces the survival rate of cultured human cells. In addition, ASPP2 is found in cytoplasm and nucleus at low Ddx42p level, and predominantly in cytoplasm at high concentration of Ddx42p, respectively. Our results show that Ddx42p is capable of modulating ASPP2 function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ankyrins / metabolism
  • Apoptosis / physiology*
  • Apoptosis Regulatory Proteins
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Nucleus / metabolism
  • Cytoplasm / metabolism
  • DEAD-box RNA Helicases / antagonists & inhibitors
  • DEAD-box RNA Helicases / genetics
  • DEAD-box RNA Helicases / metabolism*
  • Fluorescent Antibody Technique
  • Gene Library
  • HeLa Cells
  • Humans
  • Immunoprecipitation
  • Protein Transport
  • RNA, Small Interfering / pharmacology
  • Ribonucleoprotein, U2 Small Nuclear / antagonists & inhibitors
  • Ribonucleoprotein, U2 Small Nuclear / genetics
  • Ribonucleoprotein, U2 Small Nuclear / metabolism*
  • Transcriptional Activation
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism
  • Two-Hybrid System Techniques
  • src Homology Domains

Substances

  • Ankyrins
  • Apoptosis Regulatory Proteins
  • Carrier Proteins
  • RNA, Small Interfering
  • Ribonucleoprotein, U2 Small Nuclear
  • TP53 protein, human
  • TP53BP2 protein, human
  • Tumor Suppressor Protein p53
  • DDX42 protein, human
  • DEAD-box RNA Helicases