TRIM32 Protein Modulates Type I Interferon Induction and Cellular Antiviral Response by Targeting MITA/STING Protein for K63-linked Ubiquitination

• Published in: The Journal of biological chemistry Vol. 287; no. 34; pp. 28646 - 28655
• Main Authors: Zhang, Jing, Hu, Ming-Ming, Wang, Yan-Yi, Shu, Hong-Bing
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 17.08.2012; American Society for Biochemistry and Molecular Biology
• Subjects: Cell Line; DNA Viruses - genetics; DNA Viruses - metabolism; Endoplasmic Reticulum - genetics; Endoplasmic Reticulum - metabolism; Gene Knockdown Techniques; Humans; Immunology; Innate Immunity; Interferon; Interferon-beta - genetics; Interferon-beta - metabolism; Membrane Proteins - genetics; Membrane Proteins - metabolism; Mitochondria - genetics; Mitochondria - metabolism; Mitochondrial Proteins - genetics; Mitochondrial Proteins - metabolism; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; RNA Viruses - genetics; RNA Viruses - metabolism; Signal Transduction; Transcription Factors - genetics; Transcription Factors - metabolism; Tripartite Motif Proteins; Ubiquitin Ligase; Ubiquitin-Protein Ligases; Ubiquitination; Virus; Virus; Interferon; Ubiquitin Ligase; Signal Transduction; Innate Immunity
• ISSN: 0021-9258; 1083-351X; 1083-351X
• DOI: 10.1074/jbc.M112.362608

Viral infection activates several transcription factors including NF-κB and IRF3, which collaborate to induce type I interferons (IFNs) and innate antiviral response. MITA (also called STING) is a critical adaptor protein that links virus-sensing receptors to IRF3 activation upon infection by both RNA and DNA pathogens. Here we show that the E3 ubiquitin ligase tripartite motif protein 32 (TRIM32) ubiquitinated MITA and dramatically enhanced MITA-mediated induction of IFN-β. Overexpression of TRIM32 potentiated virus-triggered IFNB1 expression and cellular antiviral response. Consistently, knockdown of TRIM32 had opposite effects. TRIM32 interacted with MITA, and was located at the mitochondria and endoplasmic reticulum. TRIM32 targeted MITA for K63-linked ubiquitination at K20/150/224/236 through its E3 ubiquitin ligase activity, which promoted the interaction of MITA with TBK1. These findings suggest that TRIM32 is an important regulatory protein for innate immunity against both RNA and DNA viruses by targeting MITA for K63-linked ubiquitination and downstream activation. Background: MITA is an adapter protein critically involved in virus-triggered type I IFN induction and cellular antiviral response. Results: The E3 ligase TRIM32 targets MITA for K63-linked ubiquitination and knockdown of TRIM32 inhibits virus-triggered type I IFN induction. Conclusion: TRIM32-mediated K63-linked ubiquitination of MITA is important for cellular antiviral response. Significance: These findings provide insights on the mechanisms of regulation of cellular antiviral response.