The late promoter of the human papovavirus BK is contained within the early promoter enhancer region

ABSTRACT The expression of the proteins encoded by human papillomaviruses (HPVs) is tightly linked to the differentiation program of the infected keratinocytes. The late promoter, expressing the structural proteins, becomes activated in the differentiated keratinocytes, while the early promoter is also active in the basal layers. We have shown previously that the viral transcriptional regulator E2 and the cellular coactivator p300 cooperate in activation of gene expression of HPV8, which infects the skin and is associated with epidermodysplasia verruciformis. Here we demonstrate that this activation is further stimulated after overexpression of the E6 oncoprotein of HPV8 (8E6). RNase protection experiments revealed that 8E6 efficiently cooperates with 8E2 and p300 in activation of the late promoter. In addition, the early promoter, which did not respond to 8E2 and/or p300, was stimulated more than fourfold by 8E6. Our data suggest that both promoters are activated via distinct mechanisms, since the activation of the early promoter was achieved by the N-terminal moiety of 8E6; in contrast, its C-terminal half was sufficient for late promoter activation. This was markedly reduced by the deletion of amino acids 132 to 136 of 8E6, which also abolished the binding to p300, indicating that a direct interaction between 8E6 and p300 is involved. Moreover, a 45-amino-acid segment within the C/H3 region of p300 is required for 8E6 to stimulate the coactivator function of p300. Our results demonstrate for the first time that an E6 oncoprotein of HPV directly contributes to the regulation of HPV gene expression.

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Alteration of Human Papillomavirus Type 16 Genetic and Epigenetic Profiles in Cervical Cancer Patients Is Indicative of Poor Disease Prognosis: A Cohort Analysis

International Journal of Gynecological Cancer ◽

10.1097/igc.0000000000000679 ◽

2016 ◽

Vol 26 (4) ◽

pp. 750-757 ◽

Cited By ~ 1

Author(s):

Sankhadeep Dutta ◽

Ratnesh Kumar Singh ◽

Ranajit Kumar Mandal ◽

Susanta Roychoudhury ◽

Partha Basu ◽

...

Keyword(s):

Cervical Cancer ◽

Human Papillomavirus ◽

Viral Load ◽

Cohort Analysis ◽

Late Promoter ◽

Primary Tumor Site ◽

Primary Tumors ◽

Human Papillomavirus Type 16 ◽

Early Promoter ◽

Disease Prognosis

ObjectiveAim of this study was to assess the changes in genetic and epigenetic profiles of human papillomavirus type 16 (HPV16), if any, in primary cervical cancer (CaCx) and corresponding plasma before and after therapy for possible prognostic evaluation.MethodsThe genetic (integration status) and epigenetic (methylation of enhancer, early promoter, and late promoter sequences) profiles of HPV16 were analyzed in pretherapy CaCx (n = 46), corresponding plasma, posttherapy cervical swabs (n = 39), and corresponding plasma from a single patient cohort. Quantitative viral load was also measured in these HPV16-positive primary CaCx and posttherapy cervical swabs.ResultsPresence of HPV16 in the patients’ plasma before/after therapy was significantly (P= 0.03) associated with higher viral load in the primary tumor site. Human papillomavirus type 16 integration and hypomethylation of the early (14 of 29,Z= 4.47,P< 0.01) and late promoters (20 of 29,Z= 3.74,P< 0.01) were more prevalent in the plasma than the corresponding pretherapy CaCx samples. However, the dissimilarity in integration status (5 of 24) was less evident between posttherapy cervical swabs and corresponding plasma, although hypomethylation of the early promoter and hypermethylation of the late promoter (8 of 24,Z= 2.6,P< 0.01) was seen in posttherapy plasma samples. Whereas in the posttherapy swabs, integrated (22 of 29) or mixed (7 of 29) form of HPV16 prevailed with hypomethylation of the enhancer (6 of 29,Z= 2.0,P< 0.05) and late promoter (18 of 29,Z= 4.4,P< 0.01) compared with the corresponding primary tumors. The patients having high HPV16 copy number in pretherapy and posttherapy cervical lesions and hypomethylation of early promoter/late promoter in the corresponding plasma showed increased disease recurrence with distant metastases.ConclusionsThe genetic-epigenetic profile of HPV16 in pretherapy/posttherapy CaCx samples showed significant association with disease prognosis.

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Transcriptional mapping of two genes encoding baculovirus envelope-associated proteins

Journal of General Virology ◽

10.1099/0022-1317-83-4-937 ◽

2002 ◽

Vol 83 (4) ◽

pp. 937-943 ◽

Cited By ~ 6

Author(s):

Margot N. Pearson ◽

Rebecca L. Q. Russell ◽

George F. Rohrmann

Keyword(s):

Post Infection ◽

Promoter Sequence ◽

Start Codon ◽

Late Promoter ◽

Early Promoter ◽

Orgyia Pseudotsugata ◽

Genes Encoding ◽

Associated Proteins ◽

Infected Cells ◽

Rapid Amplification

Genes encoding two representatives of the LD130 family of baculovirus envelope-associated proteins were transcriptionally mapped. These included ld130, which encodes a low pH-induced envelope fusion protein of the Lymantria dispar multinucleocapsid nucleopolyhedrovirus, and op21, which is related to ld130 but is encoded by Orgyia pseudotsugata MNPV and appears to lack an envelope fusion activity. The size and temporal expression of mRNA of both genes were examined by Northern blot analysis of RNA extracted from infected cells at selected timepoints. In addition, 5′ rapid amplification of cDNA ends (RACE) in combination with DNA sequence analysis was used to map the start sites of mRNA. Ld130 predominately utilized its early promoter at 24 h post-infection but by 72 h post-infection ld130 expression was almost exclusively from its late promoter. In contrast, op21 was expressed predominantly from its early promoter throughout the timecourse, even though a consensus late promoter sequence was present within 100 bp of the translation start codon. A significant fraction of late transcripts that mapped to op21 were spliced transcripts originating in the op18 gene region. The 3′ termini of the transcripts were also mapped using 3′ RACE.

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