Download MendeleyStructural mechanism of CRL4-instructed STAT2 degradation via a novel cytomegaloviral DCAF receptor.
Le-Trilling, V.T.K., Banchenko, S., Paydar, D., Leipe, P.M., Binting, L., Lauer, S., Graziadei, A., Klingen, R., Gotthold, C., Burger, J., Bracht, T., Sitek, B., Jan Lebbink, R., Malyshkina, A., Mielke, T., Rappsilber, J., Spahn, C.M., Voigt, S., Trilling, M., Schwefel, D.(2023) EMBO J 42: e112351-e112351
- PubMed: 36762436
- DOI: https://doi.org/10.15252/embj.2022112351
- Primary Citation of Related Structures:
7ZN7, 7ZNN - PubMed Abstract:
Human cytomegalovirus (CMV) is a ubiquitously distributed pathogen whose rodent counterparts such as mouse and rat CMV serve as common infection models. Here, we conducted global proteome profiling of rat CMV-infected cells and uncovered a pronounced loss of the transcription factor STAT2, which is crucial for antiviral interferon signalling. Via deletion mutagenesis, we found that the viral protein E27 is required for CMV-induced STAT2 depletion. Cellular and in vitro analyses showed that E27 exploits host-cell Cullin4-RING ubiquitin ligase (CRL4) complexes to induce poly-ubiquitylation and proteasomal degradation of STAT2. Cryo-electron microscopy revealed how E27 mimics molecular surface properties of cellular CRL4 substrate receptors called DCAFs (DDB1- and Cullin4-associated factors), thereby displacing them from the catalytic core of CRL4. Moreover, structural analyses showed that E27 recruits STAT2 through a bipartite binding interface, which partially overlaps with the IRF9 binding site. Structure-based mutations in M27, the murine CMV homologue of E27, impair the interferon-suppressing capacity and virus replication in mouse models, supporting the conserved importance of DCAF mimicry for CMV immune evasion.
Organizational Affiliation:
Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
