FANCD2 Binds Human Papillomavirus Genomes and Associates with a Distinct Set of DNA Repair Proteins to Regulate Viral Replication

Spriggs, Chelsey C.; Laimins, Laimonis A.

doi:10.1128/mbio.02340-16

Cited by 37 publications

(47 citation statements)

References 55 publications

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“…Papillomavirus replication occurs near fragile sites in host DNA, where integration is believed to be facilitated by double-stranded DNA breaks in host DNA (54)(55)(56)(57)(58)(59)(60)(61). Here we show that SMC5/6 was observed to localize at papillomavirus replication foci in differentiated keratinocytes, similar to several other HR and DDR factors (31,34,35,(48)(49)(50). Disruption of the cellular HR process by depletion of SMC5/6 may affect the resolution of replicated forms of the DNA from multimers to monomers or disrupt a recombination-mediated mechanism of maintenance replication, oligomerization, and/or integration.…”

Section: Discussionsupporting

confidence: 59%

“…Another possibility is that SMC5/6 has some other role in PV replication in the maintenance phase. The DDR and HR machinery has been suggested to facilitate the initial and differentiation-dependent amplification of PV episomes, as well as maintenance of episome stability (31,34,(48)(49)(50). Whether and how PVs switch between mechanisms of DNA replication during different phases of the replication cycle and the role of the DDR/HR machinery during these stages are not yet well understood, but it is unlikely that viral DNA replication adheres to conventional rules of chromosomal DNA replication.…”

Section: Discussionmentioning

confidence: 99%

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The SMC5/6 Complex Interacts with the Papillomavirus E2 Protein and Influences Maintenance of Viral Episomal DNA

Bentley

Tan

McBride

et al. 2018

J Virol

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The papillomavirus E2 protein executes numerous essential functions related to viral transcription, replication of viral DNA, and viral genome maintenance. Because E2 lacks enzymatic activity, many of these functions are mediated by interactions with host cellular proteins. Unbiased proteomics approaches have successfully identified a number of E2-host protein interactions. We have extended such studies and have identified and validated the cellular proteins SMC5 and SMC6 as interactors of the viral E2 protein. These two proteins make up the core components of the SMC5/6 complex. The SMC5/6 complex is a member of the conserved Structural Maintenance of Chromosomes (SMC) family of proteins, which are essential for genome maintenance. We have examined the role of SMC5/6 in various E2 functions. Our data suggest that SMC6 is not required for E2-mediated transcriptional activation, E1/E2-mediated transient replication, or differentiation-dependent amplification of viral DNA. Our data however suggest a role for SMC5/6 in viral genome maintenance. The high-risk human papillomaviruses are the etiological cause of cervical cancer and the most common sexually transmitted infection. While the majority of infections may be asymptomatic or only cause benign lesions, persistent infection with the oncogenic high-risk HPV types may lead to serious diseases, such as cervical cancer, anogenital carcinoma, or head and neck oropharyngeal squamous cell carcinoma. The identification of virus-host protein interactions provides insights into the mechanisms of viral DNA persistence, viral genome replication, and cellular transformation. Elucidating the mechanism of early events in the virus replication cycle as well as of integration of viral DNA into host chromatin may present novel antiviral strategies and targets for counteracting persistent infection. The E2 protein is an important viral regulatory protein whose functions are mediated through interactions with host cell proteins. Here we explore the interaction of E2 with SMC5/6 and the functional consequences.

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Section: Discussionsupporting

confidence: 59%

Section: Discussionmentioning

confidence: 99%

The SMC5/6 Complex Interacts with the Papillomavirus E2 Protein and Influences Maintenance of Viral Episomal DNA

Bentley

Tan

McBride

et al. 2018

J Virol

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“…The epistatic analysis confirmed that ICL sensitivity in E6/E7 cells was due to a defect in FancD2 or downstream of FancD2 (Fig 1). However, FancD2 monoubiquitination and foci formation were increased in E6 or E7 cells (Fig 3-4), which is consistent with the previous work conducted in HPV+ and HPV oncogene expressing cells (27, 31). Strikingly, Ub-FancD2 was seen without cisplatin treatment in E6 expressing cells, which might be due to the presence of activated ATR which increases FancD2 monoubiquitination (9).…”

Section: Discussionsupporting

confidence: 91%

High-Risk Human Papillomavirus Oncogenes Disrupt the Fanconi Anemia DNA repair Pathway by Impairing Localization and Deubiquitination of FancD2

Khanal

Galloway

2018

Preprint

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10Persistent expression of high-risk HPV oncogenes is necessary for the development of anogenital and 11 oropharyngeal cancers. Here, we show that E6/E7 expressing cells are hypersensitive to DNA 12 crosslinking agent cisplatin and have defects in repairing DNA interstrand crosslinks (ICL). Importantly, 13 we elucidate how E6/E7 attenuate the Fanconi anemia (FA) DNA crosslink repair pathway. Though 14 E6/E7 activated the pathway by increasing FancD2 monoubiquitination and foci formation, they inhibited 15 the completion of the repair by multiple mechanisms. E6/E7 impaired FancD2 colocalization with double-16 strand breaks (DSB), which subsequently hindered the recruitment of downstream protein Rad51 to DSB 17 in E6 cells. Further, E6 expression caused delayed FancD2 de-ubiquitination, an important process for 18 effective ICL repair. Delayed FancD2 de-ubiquitination was attributed to the increased chromatin 19 retention of FancD2 hindering USP1 de-ubiquitinating activity, and persistently activated ATR/CHK-20 1/pS565 FancI signaling. E6 mediated p53 degradation did not hamper the cell cycle specific process of 21 FancD2 modifications but abrogated repair by disrupting FancD2 de-ubiquitination. Further, E6 reduced 22 the expression and foci formation of Palb2, which is a repair protein downstream of FancD2. These 23 findings uncover unique mechanisms by which HPV oncogenes contribute to genomic instability and the 24 response to cisplatin therapies. 25 42 High-risk human papillomavirus (HR-HPV) E6/E7 oncoproteins are essential for the development of 43 malignancies of the anogenital tract and oropharynx, with HPV16 being the predominant type (1). 44 Cervical and oropharyngeal cancers are the most common HPV-associated malignancies among females 45 and males, respectively (2). Persistent HPV infection destabilizes the cellular genome which can lead to 46 cancer. Genomic instability is likely the result of the numerous interactions of HPV oncoproteins with 47 host tumor suppressors and DNA damage repair (DDR) proteins. Recently, we demonstrated that high-48 risk HPV oncogenes attenuate double-strand break (DSB) repair by impairing the homologous 49 recombination pathway (3). To further elucidate the mechanisms by which HPV oncogenes impair DDR, 50 the present study focuses on the impact of HPV16 oncogenes on the Fanconi anemia-BRCA (FA or FA-51 BRCA) pathway. 52The FA-BRCA pathway is involved in the repair of intra or interstrand crosslinks (ICL), thereby 53 maintaining genomic stability (4, 5) ( Fig S1). ICLs block DNA replication and transcription and, thus, 54 are highly cytotoxic to cells if not repaired. The FA pathway is composed of 22 FA proteins (identified to 55 date) (6). When any one of the FA genes of the FA-BRCA pathway is mutated, individuals have a 56 spectrum of disorders, called Fanconi Anemia, characterized by bone marrow failure, congenital 57 malformations, cancer predisposition, and cellular sensitivity to ICL-inducing agents (7). Upon exposure 58 to DNA crosslinking agents, and during S-phase o...

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“…RPA phosphorylated on Ser33, a target of ATR, localizes to HPV31 replication foci, suggesting that RS occurs on viral DNA (55). Indeed, several factors involved in HR repair as well as in replication fork protection and restart (e.g., FANCD2, BRCA1, and Rad51) are bound to HPV genomes and are necessary for viral replication (56)(57)(58)(59)(60)(61). ATR effectors are also recruited to HPV18 replication foci during transient replication in U20S cells, which mimics establishment replication, suggesting that RS occurs on viral DNA during the initial amplification (62).…”

Section: Hpv Harnesses the Replication Stress Response For Replicationmentioning

confidence: 99%

Impact of Replication Stress in Human Papillomavirus Pathogenesis

Moody

2019

J Virol

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The inactivation of critical cell cycle checkpoints by the human papillomavirus (HPV) oncoprotein E7 results in replication stress (RS) that leads to genomic instability in premalignant lesions. Intriguingly, RS tolerance is achieved through several mechanisms, enabling HPV to exploit the cellular RS response for viral replication and to facilitate viral persistence in the presence of DNA damage. As such, inhibitors of the RS response pathway may provide a novel approach to target HPV-associated lesions and cancers.

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FANCD2 Binds Human Papillomavirus Genomes and Associates with a Distinct Set of DNA Repair Proteins to Regulate Viral Replication

Cited by 37 publications

References 55 publications

The SMC5/6 Complex Interacts with the Papillomavirus E2 Protein and Influences Maintenance of Viral Episomal DNA

The SMC5/6 Complex Interacts with the Papillomavirus E2 Protein and Influences Maintenance of Viral Episomal DNA

High-Risk Human Papillomavirus Oncogenes Disrupt the Fanconi Anemia DNA repair Pathway by Impairing Localization and Deubiquitination of FancD2

Impact of Replication Stress in Human Papillomavirus Pathogenesis

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