B cell lymphoma (Bcl)-2 protein is the major determinant in bcl-2 adenine-uridine-rich element turnover overcoming HuR activity

J Biol Chem. 2009 Jul 31;284(31):20946-55. doi: 10.1074/jbc.M109.023721. Epub 2009 Jun 11.

Abstract

In the 3'-untranslated region, the destabilizing adenine-uridine (AU)-rich elements (AREs) control the expression of several transcripts through interactions with ARE-binding proteins (AUBPs) and RNA degradation machinery. Although the fundamental role for AUBPs and associated factors in eliciting ARE-dependent degradation of cognate mRNAs has been recently highlighted, the molecular mechanisms underlying the specific regulation of individual mRNA turnover have not yet been fully elucidated. Here we focused on the post-transcriptional regulation of bcl-2 mRNA in human cell lines under different conditions and genetic backgrounds. In the context of an AUBPs silencing approach, HuR knockdown reduced the expression of endogenous bcl-2, whereas unexpectedly, a bcl-2 ARE-reporter transcript increased significantly, suggesting that HuR expression has opposite effects on endogenous and ectopic bcl-2 ARE. Moreover, evidence was provided for the essential, specific and dose-dependent role of the Bcl-2 protein in regulating the decay kinetics of its own mRNA, as ascertained by a luciferase reporter system. Altogether, the data support a model whereby the Bcl-2 protein is the major determinant of its own ARE-dependent transcript half-life in living cells and its effect overcomes the activity of ARE-binding proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Surface / metabolism*
  • Cell Line
  • Clone Cells
  • ELAV Proteins
  • ELAV-Like Protein 1
  • Gene Silencing
  • Genes, Reporter
  • Heterogeneous Nuclear Ribonucleoprotein D0
  • Heterogeneous-Nuclear Ribonucleoprotein D / metabolism
  • Humans
  • Immunoprecipitation
  • Luciferases / metabolism
  • Poly(A)-Binding Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / genetics*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • RNA Stability
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / metabolism*
  • Regulatory Sequences, Ribonucleic Acid / genetics*
  • Reproducibility of Results
  • T-Cell Intracellular Antigen-1
  • Transfection

Substances

  • Antigens, Surface
  • ELAV Proteins
  • ELAV-Like Protein 1
  • ELAVL1 protein, human
  • HNRNPD protein, human
  • Heterogeneous Nuclear Ribonucleoprotein D0
  • Heterogeneous-Nuclear Ribonucleoprotein D
  • Poly(A)-Binding Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Messenger
  • RNA-Binding Proteins
  • Regulatory Sequences, Ribonucleic Acid
  • T-Cell Intracellular Antigen-1
  • TIA1 protein, human
  • Luciferases