Related Experiment Video
Updated: Oct 1, 2025

Isolation and Quantification of Epstein-Barr Virus from the P3HR1 Cell Line
Published on: September 28, 2022
Epstein-Barr virus BNRF1 destabilizes SMC5/6 cohesin complexes to evade its restriction of replication compartments
Stephanie Pei Tung Yiu1, Rui Guo2, Cassie Zerbe3
1Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115, USA; Harvard Graduate Program in Virology, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
Epstein-Barr virus (EBV) persistently infects people worldwide. Delivery of ∼170-kb EBV genomes to nuclei and use of nuclear membrane-less replication compartments (RCs) for their lytic cycle amplification necessitate evasion of intrinsic antiviral responses. Proteomics analysis indicates that, upon B cell infection or lytic reactivation, EBV depletes the cohesin SMC5/6, which has major roles in chromosome maintenance and DNA damage repair. The major tegument protein BNRF1 targets SMC5/6 complexes by a ubiquitin proteasome pathway dependent on calpain proteolysis and Cullin-7. In the absence of BNRF1, SMC5/6 associates with R-loop structures, including at the viral lytic origin of replication, and interferes with RC formation and encapsidation. CRISPR analysis identifies RC restriction roles of SMC5/6 components involved in DNA entrapment and SUMOylation. Our study highlights SMC5/6 as an intrinsic immune sensor and restriction factor for a human herpesvirus RC and has implications for the pathogenesis of EBV-associated cancers.
Related Concept Videos
Restarting Stalled Replication Forks
Negative Regulator Molecules
Single-Strand DNA Binding Proteins
Long-patch Base Excision Repair
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of...
Viruses with RNA Genomes

