scholarly journals Identification of heterogenous nuclear ribonucleoproteins (hnRNPs) and serine- and arginine-rich (SR) proteins that induce human papillomavirus type 16 late gene expression and alter L1 mRNA splicing

2021 ◽  
Author(s):  
Chengyu Hao ◽  
Lijing Gong ◽  
Xiaoxu Cui ◽  
Johanna Jönsson ◽  
Yunji Zheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Sr Proteins ◽  
Mrna Splicing ◽  
Late Gene ◽  
Mrna Levels ◽  
Late Gene Expression ◽  
Human Papillomavirus Type 16 ◽  
Hnrnp Proteins ◽  
L1 And L2

AbstractWe have determined the effect of seven serine- and arginine-rich (SR) proteins and 15 heterogenous nuclear ribonucleoproteins (hnRNPs) on human papillomavirus type 16 (HPV16) late gene expression. Of the seven SR proteins analyzed here, SRSF1, SRSF3, and SRSF9 induced HPV16 late gene expression, and five of the SR proteins affected HPV16 L1 mRNA splicing. Of the 15 hnRNP proteins analyzed here, hnRNP A2, hnRNP F, and hnRNP H efficiently induced HPV16 late gene expression, and all of the hnRNPs affected HPV16 L1 mRNA levels or mRNA splicing. Thus, the majority of SR proteins and hnRNPs have the potential to regulate HPV16 L1 mRNA splicing. Strict control of the expression of the immunogenic L1 and L2 capsid proteins may contribute to the ability of HPV16 to cause persistence.

scholarly journals A Downstream Polyadenylation Element in Human Papillomavirus Type 16 L2 Encodes Multiple GGG Motifs and Interacts with hnRNP H

2005 ◽  
Vol 79 (14) ◽  
pp. 9254-9269 ◽  
Author(s):  
Daniel Öberg ◽  
Joanna Fay ◽  
Helen Lambkin ◽  
Stefan Schwartz
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Polyadenylation Signal ◽  
Late Gene ◽  
Coding Region ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Virus Particles ◽  
Human Papillomavirus Type 16 ◽  
L1 And L2

ABSTRACT Production of human papillomavirus type 16 (HPV-16) virus particles is totally dependent on the differentiation-dependent induction of viral L1 and L2 late gene expression. The early polyadenylation signal in HPV-16 plays a major role in the switch from the early to the late, productive stage of the viral life cycle. Here, we show that the L2 coding region of HPV-16 contains RNA elements that are necessary for polyadenylation at the early polyadenylation signal. Consecutive mutations in six GGG motifs located 174 nucleotides downstream of the polyadenylation signal resulted in a gradual decrease in polyadenylation at the early polyadenylation signal. This caused read-through into the late region, followed by production of the late mRNAs encoding L1 and L2. Binding of hnRNP H to the various triple-G mutants correlated with functional activity of the HPV-16 early polyadenylation signal. In addition, the polyadenylation factor CStF-64 was also found to interact specifically with the region in L2 located 174 nucleotides downstream of the early polyadenylation signal. Staining of cervix epithelium with anti-hnRNP H-specific antiserum revealed high expression levels of hnRNP H in the lower layers of cervical epithelium and a loss of hnRNP H production in the superficial layers, supporting a model in which a differentiation-dependent down regulation of hnRNP H causes a decrease in HPV-16 early polyadenylation and an induction of late gene expression.

scholarly journals Human papillomavirus type 16 late gene expression is regulated by cellular RNA processing factors in response to epithelial differentiation

2008 ◽  
Vol 36 (3) ◽  
pp. 522-524 ◽  
Author(s):  
Sarah A. Cumming ◽  
Thanaporn Cheun-Im ◽  
Stephen G. Milligan ◽  
Sheila V. Graham
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Current Knowledge ◽  
Regulatory Element ◽  
Epithelial Differentiation ◽  
Late Gene ◽  
Coding Region ◽  
Late Gene Expression ◽  
Human Papillomavirus Type 16 ◽  
L1 And L2

HPV16 (human papillomavirus type 16) is a 7.9 kb double-stranded DNA virus that infects anogenital mucosal epithelia. In some rare cases, in women, infection can progress to cervical cancer. HPV16 gene expression is regulated through use of multiple promoters and alternative splicing and polyadenylation. The virus genome can be divided into an early and a late coding region. The late coding region contains the L1 and L2 genes. These encode the virus capsid proteins L1 and L2; protein expression is confined to the upper epithelial layers and is regulated post-transcriptionally in response to epithelial differentiation. A 79 nt RNA regulatory element, the LRE (late regulatory element), involved in this regulation is sited at the 3′-end of the L1 gene and extends into the late 3′-UTR (3′-untranslated region). This element represses late gene expression in differentiated epithelial cells and may activate it in differentiated cells. The present paper describes our current knowledge of LRE RNA–protein interaction and their possible functions.

scholarly journals Polypyrimidine Tract Binding Protein Induces Human Papillomavirus Type 16 Late Gene Expression by Interfering with Splicing Inhibitory Elements at the Major Late 5′ Splice Site, SD3632

2008 ◽  
Vol 82 (7) ◽  
pp. 3665-3678 ◽  
Author(s):  
Monika Somberg ◽  
Xiaomin Zhao ◽  
Monika Fröhlich ◽  
Magnus Evander ◽  
Stefan Schwartz
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Splice Site ◽  
Late Gene ◽  
Polypyrimidine Tract ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
Polypyrimidine Tract Binding Protein ◽  
Cellular Factors

ABSTRACT We have initiated a screen for cellular factors that can induce human papillomavirus type 16 (HPV-16) late gene expression in human cancer cells. We report that the overexpression of polypyrimidine tract binding protein (PTB), also known as heterologous nuclear ribonucleoprotein I (hnRNP I), induces HPV-16 late gene expression in cells transfected with subgenomic HPV-16 plasmids or with full-length HPV-16 genomes and in persistently HPV-16-infected cells. In contrast, other hnRNPs such as hnRNP B1/A2, hnRNP F, and hnRNP Q do not induce HPV-16 late gene expression. PTB activates SD3632, the only 5′ splice site on the HPV-16 genome that is used exclusively by late mRNAs. PTB interferes with splicing inhibitory sequences located immediately upstream and downstream of SD3632, thereby activating late gene expression. One AU-rich PTB-responsive element was mapped to a 198-nucleotide sequence located downstream of SD3632. The deletion of this element induced HPV-16 late gene expression in the absence of PTB. Our results suggest that the overexpression of PTB interferes with cellular factors that interact with the inhibitory sequences. One may speculate that an increase in PTB levels or a reduction in the concentration of a PTB antagonist is required for the activation of HPV-16 late gene expression during the viral life cycle.

scholarly journals A Splicing Enhancer in the E4 Coding Region of Human Papillomavirus Type 16 Is Required for Early mRNA Splicing and Polyadenylation as Well as Inhibition of Premature Late Gene Expression

2005 ◽  
Vol 79 (18) ◽  
pp. 12002-12015 ◽  
Author(s):  
Margaret Rush ◽  
Xiaomin Zhao ◽  
Stefan Schwartz
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Splice Site ◽  
Late Gene ◽  
Coding Region ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
Early Region ◽  
Splicing Enhancer

ABSTRACT Successful inhibition of human papillomavirus type 16 (HPV-16) late gene expression early in the life cycle is essential for persistence of infection, the highest risk factor for cervical cancer. Our study aimed to locate regulatory RNA elements in the early region of HPV-16 that influence late gene expression. For this purpose, subgenomic HPV-16 expression plasmids under control of the strong human cytomegalovirus immediate early promoter were used. An exonic splicing enhancer that firmly supported the use of the E4 3′ splice site at position 3358 in the early region of the HPV-16 genome was identified. The enhancer was mapped to a 65-nucleotide AC-rich sequence located approximately 100 nucleotides downstream of the position 3358 3′ splice site. Deletion of the enhancer caused loss of both splicing at the upstream position 3358 3′ splice site and polyadenylation at the early polyadenylation signal, pAE. Direct splicing occurred at the competing L1 3′ splice site at position 5639 in the late region. Optimization of the position 3358 3′ splice site restored splicing to that site and polyadenylation at pAE. Additionally, a sequence of 40 nucleotides with a negative effect on late mRNA production was located immediately downstream of the enhancer. As the E4 3′ splice site is employed by both early and late mRNAs, the enhancer constitutes a key regulator of temporal HPV-16 gene expression, which is required for early mRNA production as well as for the inhibition of premature late gene expression.

Human Papillomavirus Type 16 Infection: A Morphological Spectrum with Evidence for Late Gene Expression

1987 ◽  
Vol 42 (8) ◽  
pp. 527-528
Author(s):  
MASARU MITAO ◽  
NOBUTAKA NAGAI ◽  
RICHARD U. LEVINE ◽  
SAUL J. SILVERSTEIN ◽  
CHRISTOPHER P. CRUM
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Late Gene ◽  
Late Gene Expression ◽  
Human Papillomavirus Type 16

scholarly journals SF2/ASF Binds the Human Papillomavirus Type 16 Late RNA Control Element and Is Regulated during Differentiation of Virus-Infected Epithelial Cells

2004 ◽  
Vol 78 (19) ◽  
pp. 10598-10605 ◽  
Author(s):  
Maria G. McPhillips ◽  
Thanaporn Veerapraditsin ◽  
Sarah A. Cumming ◽  
Dimitra Karali ◽  
Steven G. Milligan ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Epithelial Cells ◽  
Posttranscriptional Regulation ◽  
Regulatory Element ◽  
Sr Proteins ◽  
Control Element ◽  
Splice Sites ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16

ABSTRACT Pre-mRNA splicing occurs in the spliceosome, which is composed of small ribonucleoprotein particles (snRNPs) and many non-snRNP components. SR proteins, so called because of their C-terminal arginine- and serine-rich domains (RS domains), are essential members of this class. Recruitment of snRNPs to 5′ and 3′ splice sites is mediated and promoted by SR proteins. SR proteins also bridge splicing factors across exons to help to define these units and have a central role in alternative and enhancer-dependent splicing. Here, we show that the SR protein SF2/ASF is part of a complex that forms upon the 79-nucleotide negative regulatory element (NRE) that is thought to be pivotal in posttranscriptional regulation of late gene expression in human papillomavirus type 16 (HPV-16). However, the NRE does not contain any active splice sites, is located in the viral late 3′ untranslated region, and regulates RNA-processing events other than splicing. The level of expression and extent of phosphorylation of SF2/ASF are upregulated with epithelial differentiation, as is subcellular distribution, specifically in HPV-16-infected epithelial cells, and expression levels are controlled, at least in part, by the virus transcription regulator E2.

scholarly journals Suppression of Stromal Interferon Signaling by Human Papillomavirus 16

2019 ◽  
Vol 93 (19) ◽  
Author(s):  
Gaurav Raikhy ◽  
Brittany L. Woodby ◽  
Matthew L. Scott ◽  
Grace Shin ◽  
Julia E. Myers ◽  
...  
Keyword(s):  
Gene Expression ◽  
Innate Immunity ◽  
Human Papillomavirus ◽  
Life Cycle ◽  
Immune Evasion ◽  
Human Papillomaviruses ◽  
Keratinocyte Differentiation ◽  
Late Gene ◽  
Late Gene Expression ◽  
Viral Oncogene

ABSTRACT Human papillomaviruses (HPVs) infect squamous epithelia and cause several important cancers. Immune evasion is critical for viral persistence. Fibroblasts in the stromal microenvironment provide growth signals and cytokines that are required for proper epithelial differentiation, maintenance, and immune responses and are critical in the development of many cancers. In this study, we examined the role of epithelial-stromal interactions in the HPV16 life cycle using organotypic (raft) cultures as a model. Rafts were created using uninfected human foreskin keratinocytes (HFKs) and HFKs containing either wild-type HPV16 or HPV16 with a stop mutation to prevent the expression of the viral oncogene E5. Microarray analysis revealed significant changes in gene expression patterns in the stroma in response to HPV16, some of which were E5 dependent. Interferon (IFN)-stimulated genes (ISGs) and extracellular matrix remodeling genes were suppressed, the most prominent pathways affected. STAT1, IFNAR1, IRF3, and IRF7 were knocked down in stromal fibroblasts using lentiviral short hairpin RNA (shRNA) transduction. HPV late gene expression and viral copy number in the epithelium were increased when the stromal IFN pathway was disrupted, indicating that the stroma helps control the late phase of the HPV life cycle in the epithelium. Increased late gene expression correlated with increased late keratinocyte differentiation but not decreased IFN signaling in the epithelium. These studies show HPV16 has a paracrine effect on stromal innate immunity, reveal a new role for E5 as a stromal innate immune suppressor, and suggest that stromal IFN signaling may influence keratinocyte differentiation. IMPORTANCE The persistence of high-risk human papillomavirus (HPV) infections is the key risk factor for developing HPV-associated cancers. The ability of HPV to evade host immunity is a critical component of its ability to persist. The environment surrounding a tumor is increasingly understood to be critical in cancer development, including immune evasion. Our studies show that HPV can suppress the expression of immune-related genes in neighboring fibroblasts in a three-dimensional (3D) model of human epithelium. This finding is significant, because it indicates that HPV can control innate immunity not only in the infected cell but also in the microenvironment. In addition, the ability of HPV to regulate stromal gene expression depends in part on the viral oncogene E5, revealing a new function for this protein as an immune evasion factor.

scholarly journals Induction of the Human Papillomavirus Type 31 Late Promoter Requires Differentiation but Not DNA Amplification

2005 ◽  
Vol 79 (8) ◽  
pp. 4918-4926 ◽  
Author(s):  
Kathryn M. Spink ◽  
Laimonis A. Laimins
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Viral Genome ◽  
Copy Number ◽  
Dna Amplification ◽  
Regulatory Elements ◽  
Late Gene ◽  
Late Promoter ◽  
Late Gene Expression ◽  
Viral Copy Number

ABSTRACT The human papillomavirus (HPV) life cycle is linked to the differentiation state of the host cell. In virus-infected undifferentiated basal epithelial cells, HPV genomes are maintained as episomes at low copy number. Upon differentiation, a concomitant increase in viral copy number and an induction of late gene expression from a differentiation-specific promoter is seen. To investigate whether late gene expression was dependent on the amplification of the viral genome, inhibitors of DNA replication and in vitro systems for epithelial differentiation were used in conjunction with cells that stably maintain HPV31 episomes. Treatment of cells induced to differentiate in methylcellulose with the DNA synthesis inhibitor cytosine β-arabinofuranoside (AraC) blocked viral DNA amplification but did not prevent induction of late transcription. This suggests that late gene expression does not strictly require amplification of the viral genome and that differentiation signals alone are sufficient to activate transcription from the late promoter. However, DNA amplification does appear to be necessary for maximal induction of the late promoter. In order to examine the cis-acting elements that contribute to the activation of the late promoter, a transient reporter assay was developed. In these assays, an induction of late gene expression was seen upon differentiation that was specific to the late promoter. Mapping studies localized important regulatory elements to the E6/E7 region and identified short sequences that could serve as binding sites for transcription factors. Elements within the upstream regulatory region were also found to positively and negatively influence transcription from the late promoter. These results identify mechanisms important for the differentiation-dependent activation of late gene expression of high-risk papillomaviruses.

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