TRIM65 regulates microRNA activity by ubiquitination of TNRC6

Proc Natl Acad Sci U S A. 2014 May 13;111(19):6970-5. doi: 10.1073/pnas.1322545111. Epub 2014 Apr 28.

Abstract

MicroRNAs (miRNAs) are small evolutionarily conserved regulatory RNAs that modulate mRNA stability and translation in a wide range of cell types. MiRNAs are involved in a broad array of biological processes, including cellular proliferation, differentiation, and apoptosis. To identify previously unidentified regulators of miRNA, we initiated a systematic discovery-type proteomic analysis of the miRNA pathway interactome in human cells. Six of 66 genes identified in our proteomic screen were capable of regulating lethal-7a (let-7a) miRNA reporter activity. Tripartite motif 65 (TRIM65) was identified as a repressor of miRNA activity. Detailed analysis indicates that TRIM65 interacts and colocalizes with trinucleotide repeat containing six (TNRC6) proteins in processing body-like structures. Ubiquitination assays demonstrate that TRIM65 is an ubiquitin E3 ligase for TNRC6 proteins. The combination of overexpression and knockdown studies establishes that TRIM65 relieves miRNA-driven suppression of mRNA expression through ubiquitination and subsequent degradation of TNRC6.

Keywords: GW proteins; RNA-induced silencing complex; protein interaction networks.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins / metabolism
  • Autoantigens / genetics*
  • Autoantigens / metabolism*
  • Glioblastoma
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Intramolecular Transferases / metabolism
  • Lung Neoplasms
  • MicroRNAs / metabolism*
  • Proteomics
  • RNA Stability / physiology
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / metabolism*
  • RNA-Induced Silencing Complex / physiology
  • Tripartite Motif Proteins
  • Ubiquitin-Protein Ligases / genetics*
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination / physiology

Substances

  • Arabidopsis Proteins
  • Autoantigens
  • MicroRNAs
  • RNA-Binding Proteins
  • RNA-Induced Silencing Complex
  • TNRC6A protein, human
  • Tripartite Motif Proteins
  • Ubiquitin-Protein Ligases
  • Intramolecular Transferases
  • marneral synthase, Arabidopsis
  • TRIM65 protein, human