scholarly journals Genetic and Biochemical Analysis of cis Regulatory Elements within the Keratinocyte Enhancer Region of the Human Papillomavirus Type 31 Upstream Regulatory Region during Different Stages of the Viral Life Cycle

2004 ◽  
Vol 78 (2) ◽  
pp. 612-629 ◽  
Author(s):  
Ellora Sen ◽  
Samina Alam ◽  
Craig Meyers
Keyword(s):  
Transcription Factors ◽  
Human Papillomavirus ◽  
Life Cycle ◽  
Mutational Analysis ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Viral Life Cycle ◽  
Keratinocyte Differentiation ◽  
Viral Gene ◽  
Upstream Regulatory Region

ABSTRACT Using linker scanning mutational analysis, we recently identified potential cis regulatory elements contained within the 5′ upstream regulatory region (URR) domain and auxiliary enhancer (AE) region of the human papillomavirus type 31 (HPV31) URR involved in the regulation of E6/E7 promoter activity at different stages of the viral life cycle. For the present study, we extended the linker scanning mutational analysis to identify potential cis elements located in the keratinocyte enhancer (KE) region (nucleotides 7511 to 7762) of the HPV31 URR and to characterize cellular factors that bind to these elements under conditions representing different stages of the viral life cycle. The linker scanning mutational analysis identified viral cis elements located in the KE region that regulate transcription in the presence and absence of any viral gene products or viral DNA replication and determine the role of host tissue differentiation on viral transcriptional regulation. Using electrophoretic mobility shift assays, we illustrated defined reorganization in the composition of cellular transcription factors binding to the same cis regulatory elements at different stages of the HPV differentiation-dependent life cycle. Our studies provide an extensive map of functional elements in the KE region of the HPV31 URR, identify cis regulatory elements that exhibit significant transcription regulatory potential, and illustrate changes in specific protein-DNA interactions at different stages of the viral life cycle. The variable recruitment of transcription factors to the same cis element under different cellular conditions may represent a mechanism underlying the tight link between keratinocyte differentiation and E6/E7 expression.

scholarly journals Genetic Analysis of cis Regulatory Elements within the 5′ Region of the Human Papillomavirus Type 31 Upstream Regulatory Region during Different Stages of the Viral Life Cycle

2002 ◽  
Vol 76 (10) ◽  
pp. 4798-4809 ◽  
Author(s):  
Ellora Sen ◽  
Jennifer L. Bromberg-White ◽  
Craig Meyers
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Mutational Analysis ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Viral Life Cycle ◽  
Viral Gene ◽  
Upstream Regulatory Region ◽  
Kinase C

ABSTRACT The function of the 5′ region of the upstream regulatory region (URR) in regulating E6/E7 expression in cancer-associated papillomaviruses has been largely uncharacterized. In this study we used linker-scanning mutational analysis to identify potential cis regulatory elements contained within a portion of the 5′ region of the URR that are involved in regulating transcription of the E6/E7 promoter at different stages of the viral life cycle. The mutational analysis illustrated differences in the transcriptional utilization of specific regions of the URR depending on the stage of the viral life cycle. This study identified (i) viral cis elements that regulate transcription in the presence and absence of any viral gene products or viral DNA replication, (ii) the role of host tissue differentiation in viral transcriptional regulation, and (iii) cis regulatory regions that are effected by induction of the protein kinase C pathway. Our studies have provided an extensive map of functional elements in the 5′ region (nuncleotides 7259 to 7510) of the human papillomavirus type 31 URR that are involved in the regulation of p99 promoter activity at different stages of the viral life cycle.

scholarly journals Two Novel Promoters in the Upstream Regulatory Region of Human Papillomavirus Type 31b Are Negatively Regulated by Epithelial Differentiation

1999 ◽  
Vol 73 (4) ◽  
pp. 3505-3510 ◽  
Author(s):  
Michelle A. Ozbun ◽  
Craig Meyers
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Regulatory Region ◽  
Viral Life Cycle ◽  
Epithelial Differentiation ◽  
Upstream Regulatory Region ◽  
Organotypic Cultures

ABSTRACT Organotypic cultures support the stratification and differentiation of keratinocytes and the human papillomavirus (HPV) life cycle. We report transcription from four novel promoters in the HPV31b upstream regulatory region during the viral life cycle in organotypic cultures. Promoter initiation was not differentiation dependent; two promoters were down-regulated upon epithelial differentiation.

Identification of cis-regulatory elements in the upstream regulatory region of human papillomavirus type 59

1997 ◽  
Vol 47 (2) ◽  
pp. 155-166 ◽  
Author(s):  
Jaerang Rho ◽  
Soyoung Lee ◽  
Ethel-Michele de Villiers ◽  
Joonho Choe
Keyword(s):  
Human Papillomavirus ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Upstream Regulatory Region

scholarly journals Quantitative Role of the Human Papillomavirus Type 16 E5 Gene during the Productive Stage of the Viral Life Cycle

2003 ◽  
Vol 77 (5) ◽  
pp. 2832-2842 ◽  
Author(s):  
Sybil M. Genther ◽  
Stephanie Sterling ◽  
Stefan Duensing ◽  
Karl Münger ◽  
Carol Sattler ◽  
...  
Keyword(s):  
Life Cycle ◽  
Epithelial Cells ◽  
Dna Synthesis ◽  
Viral Gene Expression ◽  
Viral Life Cycle ◽  
Human Papillomaviruses ◽  
Keratinocyte Differentiation ◽  
Viral Gene ◽  
Viral Dna

ABSTRACT Human papillomaviruses (HPVs) are small circular DNA viruses that cause warts. Infection with high-risk anogenital HPVs, such as HPV type 16 (HPV16), is associated with human cancers, specifically cervical cancer. The life cycle of HPVs is intimately tied to the differentiation status of the host epithelium and has two distinct stages: the nonproductive stage and the productive stage. In the nonproductive stage, which arises in the poorly differentiated basal epithelial compartment of a wart, the virus maintains itself as a low-copy-number nuclear plasmid. In the productive stage, which arises as the host cell undergoes terminal differentiation, viral DNA is amplified; the capsid genes, L1 and L2, are expressed; and progeny virions are produced. This stage of the viral life cycle relies on the ability of the virus to reprogram the differentiated cells to support DNA synthesis. Papillomaviruses encode multiple oncoproteins, E5, E6, and E7. In the present study, we analyze the role of one of these viral oncogenes, E5, in the viral life cycle. To assess the role of E5 in the HPV16 life cycle, we introduced wild-type (WT) or E5 mutant HPV16 genomes into NIKS, a keratinocyte cell line that supports the papillomavirus life cycle. By culturing these cells under conditions that allow them to remain undifferentiated, a state similar to that of basal epithelial cells, we determined that E5 does not play an essential role in the nonproductive stage of the HPV16 life cycle. To determine if E5 plays a role in the productive stage of the viral life cycle, we cultured keratinocyte populations in organotypic raft cultures, which promote the differentiation and stratification of epithelial cells. We found that cells harboring E5 mutant genomes displayed a quantitative reduction in the percentage of suprabasal cells undergoing DNA synthesis, compared to cells containing WT HPV16 DNA. This reduction in DNA synthesis, however, did not prevent amplification of viral DNA in the differentiated cellular compartment. Likewise, late viral gene expression and the perturbation of normal keratinocyte differentiation were retained in cells harboring E5 mutant genomes. These data demonstrate that E5 plays a subtle role during the productive stage of the HPV16 life cycle.

scholarly journals The Minor Capsid Protein L2 Contributes to Two Steps in the Human Papillomavirus Type 31 Life Cycle

2005 ◽  
Vol 79 (7) ◽  
pp. 3938-3948 ◽  
Author(s):  
Sigrid C. Holmgren ◽  
Nicole A. Patterson ◽  
Michelle A. Ozbun ◽  
Paul F. Lambert
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Capsid Protein ◽  
Human Keratinocytes ◽  
Viral Life Cycle ◽  
Viral Gene ◽  
Raft Culture ◽  
Minor Capsid Protein ◽  
Virus Particles ◽  
Fold Reduction

ABSTRACT Prior studies, which have relied upon the use of pseudovirions generated in heterologous cell types, have led to sometimes conflicting conclusions regarding the role of the minor capsid protein of papillomaviruses, L2, in the viral life cycle. In this study we carry out analyses with true virus particles assembled in the natural host cell to assess L2's role in the viral infectious life cycle. For these studies we used the organotypic (raft) culture system to recapitulate the full viral life cycle of the high-risk human papillomavirus HPV31, which was either wild type or mutant for L2. After transfection, the L2 mutant HPV31 genome was able to establish itself as a nuclear plasmid in proliferating populations of poorly differentiated (basal-like) human keratinocytes and to amplify its genome to high copy number, support late viral gene expression, and cause formation of virus particles in human keratinocytes that had been induced to undergo terminal differentiation. These results indicate that aspects of both the nonproductive and productive phases of the viral life cycle occur normally in the absence of functional L2. However, upon the analysis of the virus particles generated, we found an approximate 10-fold reduction in the amount of viral DNA encapsidated into L2-deficient virions. Furthermore, there was an over-100-fold reduction in the infectivity of L2-deficient virus. Because the latter deficiency cannot be accounted for solely by the 10-fold decrease in encapsidation, we conclude that L2 contributes to at least two steps in the production of infectious virus.

scholarly journals Differential Requirements for Conserved E2 Binding Sites in the Life Cycle of Oncogenic Human Papillomavirus Type 31

1998 ◽  
Vol 72 (2) ◽  
pp. 1071-1077 ◽  
Author(s):  
Frank Stubenrauch ◽  
Hock B. Lim ◽  
Laimonis A. Laimins
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Viral Replication ◽  
Binding Sites ◽  
Regulatory Region ◽  
Viral Life Cycle ◽  
Expression Vectors ◽  
Late Gene Expression ◽  
Fourfold Increase ◽  
Proximal Site

ABSTRACT Human papillomavirus (HPV) E2 proteins regulate viral replication by binding to sites in the upstream regulatory region (URR) and by complex formation with the E1 origin recognition protein. In the genital HPV types, the distribution and location of four E2 binding sites (BS1 to BS4) which flank a single E1 binding site are highly conserved. We have examined the roles of these four E2 sites in the viral life cycle of HPV type 31 (HPV31) by using recently developed methods for the biosynthesis of papillomaviruses from transfected DNA templates (M. G. Frattini et al., Proc. Natl. Acad. Sci. USA 93:3062–3067, 1996). In transient assays, no single site was found to be necessary for replication, and mutation of the early promoter-proximal site (BS4) led to a fourfold increase in replication. Cotransfection of the HPV31 wild-type (HPV-wt) and mutant genomes with expression vectors revealed that E1 stimulated replication of HPV31-wt as well as the HPV31-BS1, -BS2, and -BS3 mutants. In contrast, increased expression of E2 decreased replication of these genomes. Replication of the HPV31-BS4 mutant genome was not further increased by cotransfection of E1 expression vectors but was stimulated by E2 coexpression. In stably transfected normal human keratinocytes, mutation of either BS1, BS3, or BS4 resulted in integration of viral genomes into host chromosomes. In contrast, mutation of BS2 had no effect on stable maintenance of episomes or copy number. Following growth of stably transfected lines in organotypic raft cultures, the differentiation-dependent induction of late gene expression and amplification of viral DNA of the BS2 mutant was found to be similar to that of HPV31-wt. We were unable to find a role for BS2 in our assays for viral functions. We conclude that at least three of the four E2 binding sites in the URRs of HPVs are essential for the productive viral life cycle. The specific arrangement of E2 binding sites within the URR appears to be more important for viral replication than merely the number of sites.

scholarly journals Variant Upstream Regulatory Region Sequences Differentially Regulate Human Papillomavirus Type 16 DNA Replication throughout the Viral Life Cycle

2005 ◽  
Vol 79 (10) ◽  
pp. 5914-5922 ◽  
Author(s):  
Walter G. Hubert
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Viral Replication ◽  
Regulatory Region ◽  
Dna Amplification ◽  
Plasmid Replication ◽  
Upstream Regulatory Region ◽  
Viral Genomes ◽  
Human Papillomavirus Type 16 ◽  
Replication Factors

ABSTRACT While the central role of the viral upstream regulatory region (URR) in the human papillomavirus (HPV) life cycle has been well established, its effects on viral replication factor expression and plasmid replication of HPV type 16 (HPV16) remain unclear. Some nonprototypic variants of HPV16 contain altered URR sequences and are considered to increase the oncogenic risk of infections. To determine the relationship between viral replication and variant URRs, hybrid viral genomes were constructed with the replication-competent HPV16 prototype W12 and analyzed in assays which recapitulate the different phases of normal viral replication. The establishment efficiencies of hybrid HPV16 genomes differed about 20-fold among European prototypes and variants from Africa and America. Generally, European and African genomes exhibited the lowest replication efficiencies. The high replication levels observed with American variants were primarily attributable to their efficient expression of the replication factors E1 and E2. The maintenance levels of these viral genomes varied about fivefold, which correlated with their respective establishment phenotypes and published P97 activities. Vegetative DNA amplification could also be observed with replicating HPV16 genomes. These results indicate that efficient E1/E2 expression and elevated plasmid replication levels during the persistent stage of infection may comprise a risk factor in HPV16-mediated oncogenesis.

scholarly journals Transcription of the Human 5-Hydroxytryptamine Receptor 2B (HTR2B) Gene Is under the Regulatory Influence of the Transcription Factors NFI and RUNX1 in Human Uveal Melanoma

2018 ◽  
Vol 19 (10) ◽  
pp. 3272 ◽  
Author(s):  
Manel Benhassine ◽  
Sylvain Guérin
Keyword(s):  
Transcription Factors ◽  
Uveal Melanoma ◽  
Serotonin Receptor ◽  
Molecular Mechanisms ◽  
Regulatory Region ◽  
Gene Signature ◽  
Regulatory Elements ◽  
Gene Encoding ◽  
Aberrant Expression ◽  
Factor I

Because it accounts for 70% of all eye cancers, uveal melanoma (UM) is therefore the most common primary ocular malignancy. In this study, we investigated the molecular mechanisms leading to the aberrant expression of the gene encoding the serotonin receptor 2B (HTR2B), one of the most discriminating among the candidates from the class II gene signature, in metastatic and non-metastatic UM cell lines. Transfection analyses revealed that the upstream regulatory region of the HTR2B gene contains a combination of alternative positive and negative regulatory elements functional in HTR2B− but not in HTR23B+ UM cells. We demonstrated that both the transcription factors nuclear factor I (NFI) and Runt-related transcription factor I (RUNX1) interact with regulatory elements from the HTR2B gene to either activate (NFI) or repress (RUNX1) HTR2B expression in UM cells. The results of this study will help understand better the molecular mechanisms accounting for the abnormal expression of the HTR2B gene in uveal melanoma.

Targeted modification of promoters

2021 ◽  
pp. 247-278
Author(s):  
Andika Gunadi ◽  
◽  
Ning Zhang ◽  
John J. Finer ◽  
◽  
...  
Keyword(s):  
Gene Expression ◽  
Genome Editing ◽  
Promoter Region ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Upstream Regulatory Region ◽  
Precise Control ◽  
Coding Regions ◽  
Gene Coding ◽  
Altered Regulation

Although most genome editing efforts focus on modifications to gene coding regions, this chapter emphasizes genome editing of the upstream regulatory regions. Thoughtful editing of the promoter region will ultimately lead to improved plants, modified for more precise control of the intensity and specificity of native gene expression. In this chapter, we present an overview of the promoter or upstream regulatory region of a gene, and describe how this sequence is defined and studied. We then describe how the composition and arrangements of cis-regulatory elements within the promoter and the leading intron associated with the promoter region have been studied using classical transgenic approaches to reveal what regulatory components might be suitable for genome editing approaches. Finally, we offer some suggestions for pursuit of promoter editing and gene expression modulation, which will eventually lead to modified plants with an altered regulation of native gene expression.

scholarly journals SAMHD1 Regulates Human Papillomavirus 16-Induced Cell Proliferation and Viral Replication during Differentiation of Keratinocytes

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Claire D. James ◽  
Apurva T. Prabhakar ◽  
Raymonde Otoa ◽  
Michael R. Evans ◽  
Xu Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Human Papillomavirus ◽  
Life Cycle ◽  
Viral Replication ◽  
Cellular Proliferation ◽  
Specific Interaction ◽  
Viral Life Cycle ◽  
Human Papillomaviruses ◽  
Cellular Growth ◽  
Human Papillomavirus 16

ABSTRACT Human papillomaviruses induce a host of anogenital cancers, as well as oropharyngeal cancer (HPV+OPC); human papillomavirus 16 (HPV16) is causative in around 90% of HPV+OPC cases. Using telomerase reverse transcriptase (TERT) immortalized foreskin keratinocytes (N/Tert-1), we have identified significant host gene reprogramming by HPV16 (N/Tert-1+HPV16) and demonstrated that N/Tert-1+HPV16 support late stages of the viral life cycle. Expression of the cellular dNTPase and homologous recombination factor sterile alpha motif and histidine-aspartic domain HD-containing protein 1 (SAMHD1) is transcriptionally regulated by HPV16 in N/Tert-1. CRISPR/Cas9 removal of SAMHD1 from N/Tert-1 and N/Tert-1+HPV16 demonstrates that SAMHD1 controls cell proliferation of N/Tert-1 only in the presence of HPV16; the deletion of SAMHD1 promotes hyperproliferation of N/Tert-1+HPV16 cells in organotypic raft cultures but has no effect on N/Tert-1. Viral replication is also elevated in the absence of SAMHD1. This new system has allowed us to identify a specific interaction between SAMHD1 and HPV16 that regulates host cell proliferation and viral replication; such studies are problematic in nonimmortalized primary keratinocytes due to their limited life span. To confirm the relevance of our results, we repeated the analysis with human tonsil keratinocytes (HTK) immortalized by HPV16 (HTK+HPV16) and observed the same hyperproliferative phenotype following CRISPR/Cas9 editing of SAMHD1. Identical results were obtained with three independent CRISPR/Cas9 guide RNAs. The isogenic pairing of N/Tert-1 with N/Tert-1+HPV16, combined with HTK+HPV16, presents a unique system to identify host genes whose products functionally interact with HPV16 to regulate host cellular growth in keratinocytes. IMPORTANCE HPVs are causative agents in human cancers and are responsible for around of 5% of all cancers. A better understanding of the viral life cycle in keratinocytes will facilitate the development of novel therapeutics to combat HPV-positive cancers. Here, we present a unique keratinocyte model to identify host proteins that specifically interact with HPV16. Using this system, we report that a cellular gene, SAMHD1, is regulated by HPV16 at the RNA and protein levels in keratinocytes. Elimination of SAMHD1 from these cells using CRISPR/Cas9 editing promotes enhanced cellular proliferation by HPV16 in keratinocytes and elevated viral replication but not in keratinocytes that do not have HPV16. Our study demonstrates a specific intricate interplay between HPV16 and SAMHD1 during the viral life cycle and establishes a unique model system to assist exploring host factors critical for HPV pathogenesis.

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