TRIM65 regulates microRNA activity by ubiquitination of TNRC6.
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.
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115 shitao_li@hms.harvard.edu dorf@hms.harvard.edu.
Shitao
S
Li
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115.
Lingyan
L
Wang
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115.
Bishi
B
Fu
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115.
Michael A
MA
Berman
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115.
Alos
A
Diallo
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115 shitao_li@hms.harvard.edu dorf@hms.harvard.edu.
Martin E
ME
Dorf
D029681:Arabidopsis Proteins / Q000378:metabolism; D001324:Autoantigens / Q000235:genetics* / Q000378:metabolism*; D005909:Glioblastoma; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D019751:Intramolecular Transferases / Q000378:metabolism; D008175:Lung Neoplasms; D035683:MicroRNAs / Q000378:metabolism*; D040901:Proteomics; D020871:RNA Stability / Q000502:physiology; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D034743:RNA-Induced Silencing Complex / Q000502:physiology; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism*; D054875:Ubiquitination / Q000502:physiology
D029681:Arabidopsis Proteins; D001324:Autoantigens; D035683:MicroRNAs; D016601:RNA-Binding Proteins; D034743:RNA-Induced Silencing Complex; C465663:TNRC6A protein, human; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases; D019751:Intramolecular Transferases; C568454:marneral synthase, Arabidopsis; C000589384:TRIM65 protein, human
GW proteins; RNA-induced silencing complex; protein interaction networks