Mechanism of TRIM25 Catalytic Activation in the Antiviral RIG-I Pathway

Autor: Jacint G. Sanchez, Jessica J. Chiang, Konstantin M.J. Sparrer, Steven L. Alam, Michael Chi, Marcin D. Roganowicz, Banumathi Sankaran, Michaela U. Gack, Owen Pornillos
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Cell Reports, Vol 16, Iss 5, Pp 1315-1325 (2016)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2016.06.070
Popis: Antiviral response pathways induce interferon by higher-order assembly of signaling complexes called signalosomes. Assembly of the RIG-I signalosome is regulated by K63-linked polyubiquitin chains, which are synthesized by the E3 ubiquitin ligase, TRIM25. We have previously shown that the TRIM25 coiled-coil domain is a stable, antiparallel dimer that positions two catalytic RING domains on opposite ends of an elongated rod. We now show that the RING domain is a separate self-association motif that engages ubiquitin-conjugated E2 enzymes as a dimer. RING dimerization is required for catalysis, TRIM25-mediated RIG-I ubiquitination, interferon induction, and antiviral activity. We also provide evidence that RING dimerization and E3 ligase activity are promoted by binding of the TRIM25 SPRY domain to the RIG-I effector domain. These results indicate that TRIM25 actively participates in higher-order assembly of the RIG-I signalosome and helps to fine-tune the efficiency of the RIG-I-mediated antiviral response.
Databáze: Directory of Open Access Journals