CK2 phosphorylation of human papillomavirus 16 E2 on serine 23 promotes interaction with TopBP1 and is critical for E2 interaction with mitotic chromatin and the viral life cycle

Prabhakar, A. T. et al. (2021) CK2 phosphorylation of human papillomavirus 16 E2 on serine 23 promotes interaction with TopBP1 and is critical for E2 interaction with mitotic chromatin and the viral life cycle. mBio, 12, e01163-21. (doi: 10.1128/mbio.01163-21) (PMID:34544280) (PMCID:PMC8546539)

[img] Text
250008.pdf - Published Version
Available under License Creative Commons Attribution.

3MB

Abstract

During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 in vitro and in vivo and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A (E2 with serine 23 mutated to alanine) activates and represses transcription identically to E2-WT (wild-type E2), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Remarkably, S23A cells had a disrupted viral life cycle in organotypic raft cultures, with a loss of E2 expression and a failure of viral replication. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and that this interaction is critical for the viral life cycle.

Item Type:Articles
Additional Information:This work was supported by VCU Philips Institute for Oral Health Research and the National Cancer Institute Designated Massey Cancer Center grant P30 CA016059 (IMM), Cancer Research UK C6992/A12695 (IMM and BOS), Cancer Research UK C302/A14532 (MD, AWO and LHP) and Cancer Research UK C302/A24386 (MD, AWO and LHP).
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Donaldson, Dr Mary and Smith, Dr Brian
Authors: Prabhakar, A. T., James, C. D., Das, D., Otoa, R., Day, M., Burgner, J., Fontan, C. T., Wang, X., Wieland, A., Donaldson, M. M., Bristol, M. L., Li, R., Oliver, A. W., Pearl, L. H., Smith, B. O., Glass, S., and Morgan, I. M.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
University Services > Library and Collection Services > Library
Journal Name:mBio
Publisher:American Society for Microbiology
ISSN:2161-2129
ISSN (Online):2150-7511
Published Online:21 September 2021
Copyright Holders:Copyright © 2021 Prabhakar et al.
First Published:First published in mBio 12:e01163-21
Publisher Policy:Reproduced under a Creative Commons licence
Related URLs:

University Staff: Request a correction | Enlighten Editors: Update this record