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

Bentley, Peris; Tan, Min; McBride, Alison A.; White, Elizabeth; Howley, Peter M.

doi:10.1128/jvi.00356-18

Cited by 36 publications

(35 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While our findings are in agreement with others describing an antiviral function for SMC5/6 [ 8 , 9 , 10 , 11 ], they contrast with a previous report in which SMC5/6 was not found to repress HPV-31 replication or transcription, but was instead necessary for the maintenance of viral genomes [ 12 ]. This discrepancy has several possible explanations.…”

Section: Discussionsupporting

confidence: 88%

“…The SMC5/6 complex ( Figure 1 A) subunit SMC6 reportedly co-precipitates with several HPV E2 proteins [ 12 , 13 , 14 ], so we began our investigation by attempting to confirm this interaction with HPV-31 E2. HEK293 cells were transfected with FLAG-SMC6, HPV-31 V5-E2, or both plasmids, and FLAG-SMC6 immunoprecipitation (IP) was then performed using the M2 anti-FLAG antibody.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, antiviral roles have been described for SMC5/6, whereby SMC5/6 restricts transcription of hepatitis B [ 8 , 9 , 10 , 11 ] and herpes simplex-1 (HSV-1) viruses [ 11 ]. SMC5/6 has also been found to interact with both high- and low-risk HPV E2 proteins and is purportedly involved in HPV genome maintenance [ 12 ], but the significance of SMC5/6 interactions with E2 and its role during the HPV life cycle is not fully understood.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The SMC5/6 Complex Represses the Replicative Program of High-Risk Human Papillomavirus Type 31

Gibson

Androphy

2020

Pathogens

View full text Add to dashboard Cite

The multi-subunit structural maintenance of chromosomes (SMC) 5/6 complex includes SMC6 and non-SMC element (NSE)3. SMC5/6 is essential for homologous recombination DNA repair and functions as an antiviral factor during hepatitis B (HBV) and herpes simplex-1 (HSV-1) viral infections. Intriguingly, SMC5/6 has been found to associate with high-risk human papillomavirus (HPV) E2 regulatory proteins, but the functions of this interaction and its role during HPV infection remain unclear. Here, we further characterize SMC5/6 interactions with HPV-31 E2 and its role in the HPV life cycle. Co-immunoprecipitation (co-IP) revealed that SMC6 interactions with HPV-31 E2 require the E2 transactivation domain, implying that SMC5/6 interacts with full-length E2. Using chromatin immunoprecipitation, we found that SMC6 is present on HPV-31 episomes at E2 binding sites. Th depletion of SMC6 and NSE3 increased viral replication and transcription in keratinocytes maintaining episomal HPV-31, indicating that SMC5/6 restricts the viral replicative program. SMC6 interactions with E2 were reduced in the presence of HPV-31 E1, suggesting that SMC6 and E1 compete for E2 binding. Our findings demonstrate SMC5/6 functions as a repressor of the viral replicative program and this may involve inhibiting the initiation of viral replication.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The SMC5/6 Complex Represses the Replicative Program of High-Risk Human Papillomavirus Type 31

Gibson

Androphy

2020

Pathogens

View full text Add to dashboard Cite

show abstract

“…Generation of NOKs+HPV16 clones was described previously (31). N/Tert-1+E2 were prepared using the plasmids described in (60) to generate retroviruses for infection of N/Tert-1 as described (61).…”

Section: Methodsmentioning

confidence: 99%

Human papillomavirus 16 E2 regulates keratinocyte gene expression relevant to cancer and the viral life cycle

Evans

James

Bristol

et al. 2018

Preprint

View full text Add to dashboard Cite

14Human papillomaviruses (HPV) are causative agents in ano-genital and oropharyngeal cancers. 15 The virus must reprogram host gene expression to promote infection, and E6 and E7 contribute 16 to this via targeting of cellular transcription factors including p53 and pRb, respectively. The 17 HPV16 E2 protein regulates host gene expression in U2OS cells and in this study we extend 18 these observations into TERT immortalized oral keratinocytes (NOKs) that are capable of 19 supporting late stages of the HPV16 life cycle. We observed repression of innate immune genes 20 by E2 that are also repressed by the intact HPV16 genome in NOKs. RNA-seq data identified 21 167 up and 395 downregulated genes by E2; there was a highly significant overlap of the E2 22 regulated genes with those regulated by the intact HPV16 genome in the same cell type. siRNA 23 targeting of E2 reversed repression of E2 targeted genes. The ability of E2 to repress innate 24 immune genes was confirmed in an ano-genital immortalized keratinocyte cell line, N/Tert-1. 25 We present analysis of data from The Cancer Genome Atlas (TCGA) for HPV16 positive and 26 negative head and neck cancers (HNC) suggesting that E2 plays a role in regulation of the host 27 genome in cancers. Patients with HPV16 positive HNC with a loss of E2 expression exhibit a 28 worse clinical outcome and we discuss how this could, at least partially, be related to the loss of 29 E2 host gene regulation. 30 31 Importance 32 HPV16 positive tumors that retain expression of E2 have a better clinical outcome than those 33 that have lost E2 expression. It has been suggested that this is due to a loss of E2 repression of 34 E6 and E7 expression but this is not supported by data from tumors where there is not more E6 35 3 and E7 expression in the absence of E2. Here we report that E2 regulates host gene expression 36 and place this regulation in context of the HPV16 life cycle and HPV16 positive head and neck 37 cancers (the majority of which retain E2 expression). We propose that this E2 function may play 38 an important part in the increased response of HPV16 positive cancers to radiation therapy. 39 Therefore, host gene regulation by E2 may be important for promotion of the HPV16 life cycle, 40 and also for the response of HPV16 positive tumors to radiation therapy. 41 42 43 44 High risk human papillomaviruses (HR-HPV) are etiological agents in ano-genital and 45 oropharyngeal cancers (1). HPV16 is causative in around 50% of HPV positive cervical cancers 46 (HPV+CC) and 90% of HPV positive oropharyngeal cancers (HPV+OPC), the latter of which 47 has reached epidemic proportions over the past generation (2-5). 48 Following infection, HPV DNA ultimately reaches the nucleus where cellular factors induce 49 transcription from the viral genome. The viral oncogenes E6 and E7 create an environment that 50 promotes cellular proliferation and one aspect of this manipulation is the alteration of host gene 51 transcription. E7 binds to pocket proteins pRb, p130 and p107 and blo...

show abstract

“…For example, the Hepatitis B X protein hijacks the DNA damage binding protein 1 (DDD1)-containing E3 ligases to target the Smc5/6 complex for degradation [ 106 ]. The papillomavirus E2 protein is another example of a viral protein to target Smc5/6 complex, which was reported to play a role in the maintenance of the viral genome [ 107 ].…”

Section: Resultsmentioning

confidence: 99%

A Comprehensive Proteomics Analysis of the JC Virus (JCV) Large and Small Tumor Antigen Interacting Proteins: Large T Primarily Targets the Host Protein Complexes with V-ATPase and Ubiquitin Ligase Activities While Small t Mostly Associates with Those Having Phosphatase and Chromatin-Remodeling Functions

Saribas

Safak

2020

Viruses

View full text Add to dashboard Cite

The oncogenic potential of both the polyomavirus large (LT-Ag) and small (Sm t-Ag) tumor antigens has been previously demonstrated in both tissue culture and animal models. Even the contribution of the MCPyV tumor antigens to the development of an aggressive human skin cancer, Merkel cell carcinoma, has been recently established. To date, the known primary targets of these tumor antigens include several tumor suppressors such as pRb, p53, and PP2A. However, a comprehensive list of the host proteins targeted by these proteins remains largely unknown. Here, we report the first interactome of JCV LT-Ag and Sm t-Ag by employing two independent “affinity purification/mass spectroscopy” (AP/MS) assays. The proteomics data identified novel targets for both tumor antigens while confirming some of the previously reported interactions. LT-Ag was found to primarily target the protein complexes with ATPase (v-ATPase and Smc5/6 complex), phosphatase (PP4 and PP1), and ligase (E3-ubiquitin) activities. In contrast, the major targets of Sm t-Ag were identified as Smarca1/6, AIFM1, SdhA/B, PP2A, and p53. The interactions between “LT-Ag and SdhB”, “Sm t-Ag and Smarca5”, and “Sm t-Ag and SDH” were further validated by biochemical assays. Interestingly, perturbations in some of the LT-Ag and Sm t-Ag targets identified in this study were previously shown to be associated with oncogenesis, suggesting new roles for both tumor antigens in novel oncogenic pathways. This comprehensive data establishes new foundations to further unravel the new roles for JCV tumor antigens in oncogenesis and the viral life cycle.

show abstract

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

Cited by 36 publications

References 71 publications

The SMC5/6 Complex Represses the Replicative Program of High-Risk Human Papillomavirus Type 31

The SMC5/6 Complex Represses the Replicative Program of High-Risk Human Papillomavirus Type 31

Human papillomavirus 16 E2 regulates keratinocyte gene expression relevant to cancer and the viral life cycle

Contact Info

Product

Resources

About