TRIM25 Enhances the Antiviral Action of Zinc-Finger Antiviral Protein (ZAP)

PLoS Pathogens

Akinori Takaoka¹  Pamela Cheung²  Zerlina Lau²  Dan P. Felsenfeld²  William M. Schneider³  Charles M. Rice³  Leonia Bozzacco³  Margaret R. MacDonald³  Eduardo G. Aguilar³  Melody M. H. Li³  Henrik Molina⁴  Eugen Buehler⁵ 

[1] Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan;Integrated Screening Core, Experimental Therapeutics Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America;Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, New York, United States of America;Proteomics Resource Center, The Rockefeller University, New York, New York, United States of America;Trans-NIH RNAi Screening Facility, Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, United States of America

关键词: Small interfering RNAs;    293T cells;    Ubiquitination;    Cloning;    Immunoprecipitation;    Genetic screens;    Luciferase;    Viral replication;   

DOI  :  10.1371/journal.ppat.1006145

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The host factor and interferon (IFN)-stimulated gene (ISG) product, zinc-finger antiviral protein (ZAP), inhibits a number of diverse viruses by usurping and intersecting with multiple cellular pathways. To elucidate its antiviral mechanism, we perform a loss-of-function genome-wide RNAi screen to identify cellular cofactors required for ZAP antiviral activity against the prototype alphavirus, Sindbis virus (SINV). In order to exclude off-target effects, we carry out stringent confirmatory assays to verify the top hits. Important ZAP-liaising partners identified include proteins involved in membrane ion permeability, type I IFN signaling, and post-translational protein modification. The factor contributing most to the antiviral function of ZAP is TRIM25, an E3 ubiquitin and ISG15 ligase. We demonstrate here that TRIM25 interacts with ZAP through the SPRY domain, and TRIM25 mutants lacking the RING or coiled coil domain fail to stimulate ZAP’s antiviral activity, suggesting that both TRIM25 ligase activity and its ability to form oligomers are critical for its cofactor function. TRIM25 increases the modification of both the short and long ZAP isoforms by K48- and K63-linked polyubiquitin, although ubiquitination of ZAP does not directly affect its antiviral activity. However, TRIM25 is critical for ZAP’s ability to inhibit translation of the incoming SINV genome. Taken together, these data uncover TRIM25 as a bona fide ZAP cofactor that leads to increased ZAP modification enhancing its translational inhibition activity.

【 授权许可】

CC BY