HPV31 utilizes the ATR-Chk1 pathway to maintain elevated RRM2 levels and a replication-competent environment in differentiating Keratinocytes

• Type of Material: Article
• Authors: Daniel C. Anacker, University of North Carolina; Heather L. Aloor, University of North Carolina; Caitlin N. Shepard, Emory University; Gina M. Lenzi, Emory University; Bryan A. Johnson, University of North Carolina; Baek Kim, Emory University; Cary A. Moody, University of North Carolina
• Language: English
• Date: 2016-12-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016 Elsevier Inc.
• Final Published Version (URL): http://dx.doi.org/10.1016/j.virol.2016.09.028
• Title of Journal or Parent Work: Virology
• ISSN: 0042-6822
• Volume: 499
• Start Page: 383
• End Page: 396
• Grant/Funding Information: This project was supported by NIH grant 1R01CA181581 and American Cancer Society grant A14-0113 (to C.A.M.), and NIH grants R01 GM104198 and R01 AI049781 (to B.K.).
• Keywords: RIBONUCLEOTIDE REDUCTASE R2; HUMAN-PAPILLOMAVIRUS TYPE-31; DNA-DAMAGE RESPONSE; Pathogenesis; S-PHASE; LIFE-CYCLE; DNA damage response; LATE VIRAL FUNCTIONS; ONCOGENE-INDUCED SENESCENCE; Science & Technology; NUCLEOTIDE-METABOLISM; DEPENDENT UP-REGULATION; EPITHELIAL DIFFERENTIATION; Virology; Replication; Human papillomavirus; Life Sciences & Biomedicine
• Research Categories: Biology, Microbiology; Health Sciences, Immunology

Abstract

Productive replication of human papillomaviruses (HPV) is restricted to the uppermost layers of the differentiating epithelia. How HPV ensures an adequate supply of cellular substrates for viral DNA synthesis in a differentiating environment is unclear. Here, we demonstrate that HPV31 positive cells exhibit increased dNTP pools and levels of RRM2, a component of the ribonucleotide reductase (RNR) complex, which is required for de novo synthesis of dNTPs. RRM2 depletion blocks productive replication, suggesting RRM2 provides dNTPs for viral DNA synthesis in differentiating cells. We demonstrate that HPV31 regulates RRM2 levels through expression of E7 and activation of the ATR-Chk1-E2F1 DNA damage response, which is essential to combat replication stress upon entry into S-phase, as well as for productive replication. Our findings suggest a novel way in which viral DNA synthesis is regulated through activation of ATR and Chk1 and highlight an intriguing new virus/host interaction utilized for viral replication.