Evidence map›Paper›PMID 40838749›Full record

ArticleJournal of virology2025

Identification of Epstein-Barr virus BORF2 sequences required for APOBEC3B relocalization.

Farren Clark, Michael A Carpenter, Reuben S Harris, Lori Frappier

Abstract read
In one paragraph

Article in Journal of virology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Farren ClarkDepartment of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
Michael A CarpenterBiochemistry and Structural Biology Department, Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas, USA.
Reuben S HarrisBiochemistry and Structural Biology Department, Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas, USA.ORCID 0000-0002-9034-9112
Lori FrappierDepartment of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.ORCID 0000-0003-0110-5472

Funding

CIHR 183653
6 · The paper itself

Abstract

Epstein-Barr virus (EBV) is a common herpesvirus that establishes lifetime infections in most people worldwide. To protect the lytically replicating EBV genomes from mutation, the EBV BORF2 protein relocalizes the APOBEC3B cytosine deaminase out of the nucleus, sequestering it in cytoplasmic bodies. This property is conserved in BORF2 homologs in other herpesviruses, including Kaposi's sarcoma-associated herpesvirus ORF61 and herpes simplex virus 1 UL39. Here, we show that a motif conserved in these three proteins (IPAM) is critical for interactions with and relocalization of APOBEC3B. However, the properties of the cytoplasmic bodies formed by BORF2, ORF61, and UL39 differ in that only BORF2 requires APOBEC3B to form cytoplasmic bodies, and only UL39 bodies have properties of aggresomes. We also found that a SUMO-modified site in BORF2 (K741) plays an important role in the formation of bodies with endogenous APOBEC3B, both when expressed on its own and in the context of EBV infection. Additionally, nuclear BORF2-APOBEC3B bodies that formed in early lytic infection contained SUMO, suggesting the importance of SUMOylation in the sequestration of APOBEC3B. Our study provides insights into the mechanisms herpesviruses use to disable APOBEC3B and protect their replicating DNA genomes from undesired editing.IMPORTANCEHerpesviruses must protect their replicating DNA genomes from mutation by APOBEC3B, which they do by relocalizing APOBEC3B from the nucleus into cytoplasmic bodies. This is mediated by Epstein-Barr virus BORF2 and its homologs in Kaposi's sarcoma-associated herpesvirus (ORF61) and herpes simplex virus 1 (UL39). We have shown that a conserved motif in these proteins is critical for this function, and that a SUMO-modified site in BORF2 also plays an important role. This work provides insight into the mechanisms by which BORF2 and its homologs sequester and relocalize APOBEC3B, which is important for maintaining the integrity and infectivity of the respective herpesviruses.

Indexed as

Cytidine DeaminaseHerpesvirus 4, HumanMinor Histocompatibility AntigensViral ProteinsCell NucleusCytoplasmEpstein-Barr Virus InfectionsHEK293 CellsHumansAPOBEC3B protein, humanCytidine DeaminaseMinor Histocompatibility AntigensViral ProteinsAPOBEC3BEBV BORF2HSV1 UL39KSHV ORF61SUMO

Identifiers

PMID40838749
PMCPMC12455968

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.