scholarly journals Human Papillomavirus E2 Protein: Linking Replication, Transcription, and RNA Processing

2016 ◽  
Vol 90 (19) ◽  
pp. 8384-8388 ◽  
Author(s):  
Sheila V. Graham
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Rna Processing ◽  
Nucleic Acid Binding ◽  
Viral Production ◽  
Interaction Domain ◽  
E2 Protein ◽  
Protein Protein Interaction ◽  
Cellular Environment

The human papillomavirus (HPV) life cycle is tightly linked to differentiation of the infected epithelium. This means that viral proteins must exert control over epithelial gene expression in order to optimize viral production. The HPV E2 protein controls replication, transcription, and viral genome partitioning during the viral infectious life cycle. It consists of a nucleic acid-binding domain and a protein-protein interaction domain separated by a flexible serine and arginine-rich hinge region. Over the last few years, mounting evidence has uncovered an important new role for E2 in viral and cellular RNA processing. This Gem discusses the role of E2 in controlling the epithelial cellular environment and how E2 might act to coordinate late events in the viral replication cycle.

scholarly journals Regulation of clathrin coat assembly by Eps15 homology domain–mediated interactions during endocytosis

2012 ◽  
Vol 23 (4) ◽  
pp. 687-700 ◽  
Author(s):  
Ryohei Suzuki ◽  
Junko Y. Toshima ◽  
Jiro Toshima
Keyword(s):  
Functional Diversity ◽  
Protein Interaction ◽  
Interaction Domain ◽  
Protein Protein Interaction ◽  
Molecular Events ◽  
Biological Studies ◽  
Eh Domain ◽  
Actin Patch ◽  
Lines Of Evidence

Clathrin-mediated endocytosis involves a coordinated series of molecular events regulated by interactions among a variety of proteins and lipids through specific domains. One such domain is the Eps15 homology (EH) domain, a highly conserved protein–protein interaction domain present in a number of proteins distributed from yeast to mammals. Several lines of evidence suggest that the yeast EH domain–containing proteins Pan1p, End3p, and Ede1p play important roles during endocytosis. Although genetic and cell-biological studies of these proteins suggested a role for the EH domains in clathrin-mediated endocytosis, it was unclear how they regulate clathrin coat assembly. To explore the role of the EH domain in yeast endocytosis, we mutated those of Pan1p, End3p, or Ede1p, respectively, and examined the effects of single, double, or triple mutation on clathrin coat assembly. We found that mutations of the EH domain caused a defect of cargo internalization and a delay of clathrin coat assembly but had no effect on assembly of the actin patch. We also demonstrated functional redundancy among the EH domains of Pan1p, End3p, and Ede1p for endocytosis. Of interest, the dynamics of several endocytic proteins were differentially affected by various EH domain mutations, suggesting functional diversity of each EH domain.

scholarly journals The Role of Protein Kinase A Regulation of the E6 PDZ-Binding Domain during the Differentiation-Dependent Life Cycle of Human Papillomavirus Type 18

2013 ◽  
Vol 87 (17) ◽  
pp. 9463-9472 ◽  
Author(s):  
C. P. Delury ◽  
E. K. Marsh ◽  
C. D. James ◽  
S. S. Boon ◽  
L. Banks ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Binding Domain ◽  
Kinase A

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 Proteasomal Degradation of the Papillomavirus E2 Protein Is Inhibited by Overexpression of Bromodomain-Containing Protein 4

2009 ◽  
Vol 83 (9) ◽  
pp. 4127-4139 ◽  
Author(s):  
David Gagnon ◽  
Simon Joubert ◽  
Hélène Sénéchal ◽  
Amélie Fradet-Turcotte ◽  
Sabrina Torre ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Steady State ◽  
Luciferase Assay ◽  
Viral Gene ◽  
Transactivation Domain ◽  
Interaction Domain ◽  
E2 Protein ◽  
Mutant Proteins ◽  
Steady State Levels

ABSTRACT The E2 protein of human papillomavirus (HPV) binds to specific sites in the viral genome to regulate its transcription, replication, and maintenance in infected cells. Like most regulatory proteins, E2 is rapidly turned over. A high-throughput assay was developed to quantify the expression and stability of E2 in vivo, based on its fusion to Renilla luciferase (RLuc). The steady-state levels of Rluc-E2 were quantified by measuring the amounts of associated luciferase activity, and its degradation was measured by monitoring the decrease in enzymatic activity occurring after a block of translation with cycloheximide. Using this assay, the E2 proteins from a low-risk (HPV11) and a high-risk (HPV31) human papillomavirus (HPV) type were found to have short half-lives of 60 min in C33A cervical carcinoma cells and to be ubiquitinated and degraded by the proteasome. Analysis of mutant proteins showed that the instability of E2 is independent of its DNA-binding and transcriptional activities but is encoded within its transactivation domain, the region that binds to the cellular chromatin factor bromodomain-containing protein 4 (Brd4) to regulate viral gene transcription. Overexpression of Brd4, or of its C-terminal E2-interaction domain, was found to increase the steady-state levels and stability of wild-type E2 but not of E2 mutants defective for binding Brd4. These results indicate that the stability of E2 is increased upon complex formation with Brd4 and highlight the value of the luciferase assay for the study of E2 degradation.

scholarly journals A LysM Domain Intervenes in Sequential Protein-Protein and Protein-Peptidoglycan Interactions Important for Spore Coat Assembly inBacillus subtilis

2018 ◽  
Vol 201 (4) ◽  
Author(s):  
Fatima C. Pereira ◽  
Filipa Nunes ◽  
Fernando Cruz ◽  
Catarina Fernandes ◽  
Anabela L. Isidro ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Protein Interaction ◽  
Interaction Domain ◽  
Content Type ◽  
Protein Protein Interaction ◽  
Lysm Domain ◽  
Binding Function ◽  
Morphogenetic Protein ◽  
Tight Connection

ABSTRACTAt a late stage in spore development inBacillus subtilis, the mother cell directs synthesis of a layer of peptidoglycan known as the cortex between the two forespore membranes, as well as the assembly of a protective protein coat at the surface of the forespore outer membrane. SafA, the key determinant of inner coat assembly, is first recruited to the surface of the developing spore and then encases the spore under the control of the morphogenetic protein SpoVID. SafA has a LysM peptidoglycan-binding domain, SafALysM, and localizes to the cortex-coat interface in mature spores. SafALysMis followed by a region, A, required for an interaction with SpoVID and encasement. We now show that residues D10 and N30 in SafALysM, while involved in the interaction with peptidoglycan, are also required for the interaction with SpoVID and encasement. We further show that single alanine substitutions on residues S11, L12, and I39 of SafALysMthat strongly impair binding to purified cortex peptidoglycan affect a later stage in the localization of SafA that is also dependent on the activity of SpoVE, a transglycosylase required for cortex formation. The assembly of SafA thus involves sequential protein-protein and protein-peptidoglycan interactions, mediated by the LysM domain, which are required first for encasement then for the final localization of the protein in mature spores.IMPORTANCEBacillus subtilisspores are encased in a multiprotein coat that surrounds an underlying peptidoglycan layer, the cortex. How the connection between the two layers is enforced is not well established. Here, we elucidate the role of the peptidoglycan-binding LysM domain, present in two proteins, SafA and SpoVID, that govern the localization of additional proteins to the coat. We found that SafALysMis a protein-protein interaction module during the early stages of coat assembly and a cortex-binding module at late stages in morphogenesis, with the cortex-binding function promoting a tight connection between the cortex and the coat. In contrast, SpoVIDLysMfunctions only as a protein-protein interaction domain that targets SpoVID to the spore surface at the onset of coat assembly.

scholarly journals Cooperative Activation of Human Papillomavirus Type 8 Gene Expression by the E2 Protein and the Cellular Coactivator p300

2002 ◽  
Vol 76 (21) ◽  
pp. 11042-11053 ◽  
Author(s):  
Andreas Müller ◽  
Andreas Ritzkowsky ◽  
Gertrud Steger
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Specific Binding ◽  
Regulatory Region ◽  
Keratinocyte Differentiation ◽  
E2 Protein ◽  
Protein Protein Interaction ◽  
Cooperative Activation

ABSTRACT The E2 proteins of papillomaviruses (PV) bind to the coactivator CBP/p300 as do many other transcription factors, but the precise role of CBP/p300 in E2-specific functions is not yet understood. We show that the E2 protein of human PV type 8 (HPV8) directly binds to p300. Activation of HPV8 gene expression by low amounts of HPV8 E2 was stimulated up to sevenfold by coexpression of p300. The interaction between E2 and p300 may play a role in differentiation-dependent activation of PV gene expression, since we can show that the expression level of p300 increases during keratinocyte differentiation. Surprisingly, sequence-specific binding of E2 to its recognition sites within the regulatory region of HPV8 is not necessary for this cooperation, indicating that E2 can be recruited to the promoter via protein-protein interaction. HPV8 E2 binds via its N-terminal activation domain (AD), its C-terminal DNA binding domain (DBD), and its internal hinge region to p300 in vitro. Transient-transfection assays revealed that the AD is necessary and sufficient for cooperative activation with p300. However, we provide evidence that the interaction of the hinge and the DBD of HPV8 E2 with p300 may contribute. Our data suggest an important role of p300 in regulation of HPV8 gene expression and reveal a new mechanism by which E2 may be recruited to a promoter to activate transcription without sequence specific DNA binding.

scholarly journals The role of the human papillomavirus type 18 E7 oncoprotein during the complete viral life cycle

Virology ◽  
2005 ◽  
Vol 338 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Margaret E. McLaughlin-Drubin ◽  
Jennifer L. Bromberg-White ◽  
Craig Meyers
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Viral Life Cycle ◽  
E7 Oncoprotein

scholarly journals RNA processing machineries in Archaea: the 5’-3’ exoribonuclease aRNase J of the β-CASP family is engaged specifically with the helicase ASH-Ski2 and the 3’-5’ exoribonucleolytic RNA exosome machinery

2019 ◽  
Author(s):  
Duy Khanh Phung ◽  
Clarisse Etienne ◽  
Manon Batista ◽  
Petra Langendijk-Genevaux ◽  
Yann Moalic ◽  
...  
Keyword(s):  
Rna Processing ◽  
Cell Extract ◽  
Rna Helicases ◽  
Rna Surveillance ◽  
Protein Protein Interaction ◽  
Rna Exosome ◽  
First Time

ABSTRACTA network of RNA helicases, endoribonucleases, and exoribonucleases regulates the quantity and quality of cellular RNAs. To date, mechanistic studies focused on bacterial and eukaryal systems due to the challenge of identifying the main drivers of RNA decay and processing in Archaea. Here, our data support that aRNase J, a 5’-3’ exoribonuclease of the β-CASP family conserved in Euryarchaea, engages specifically with a Ski2-like helicase and the RNA exosome to potentially exert control over RNA surveillance, and that this occurs in the vicinity of the ribosome. Proteomic landscapes and direct protein-protein interaction analyses demonstrated that aRNase J interplay with ASH-Ski2 and the Csl4 cap exosome subunit. These in vitro data are strengthened by our phylogenomic studies showing a taxonomic co-distribution of aRNase J and ASH-Ski2 among the archaeal phylogeny. Finally, our T. barophilus whole-cell extract fractionation experiments provide evidences that an aRNase J/ASH-Ski2 complex might exist in vivo and hint at an association of aRNase J with the ribosome or polysomes that is stressed in absence of ASH-Ski2. While aRNase J homologues are found among bacteria, the RNA exosome and the Ski2-like RNA helicase have eukaryotic homologues, underlining the mosaic aspect of archaeal RNA machines. Altogether, these results suggest, for the first time, a fundamental role of β-CASP RNase/helicase complex in archaeal RNA metabolism. Finally, our results position aRNase J at the junction of RNA surveillance and translation processes, thus opening new perspectives and evolutionary scenario on RNA processing players in Archaea.

scholarly journals Human Papillomavirus Type 16 E2 Protein Has No Effect on Transcription from Episomal Viral DNA

2003 ◽  
Vol 77 (3) ◽  
pp. 2021-2028 ◽  
Author(s):  
Viviane Bechtold ◽  
Peter Beard ◽  
Kenneth Raj
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Cell Lines ◽  
Trichostatin A ◽  
Viral Dna ◽  
Secondary Importance ◽  
E2 Protein ◽  
Hpv Dna ◽  
Episomal Hpv16 ◽  
E6 And E7

ABSTRACT The human papillomavirus (HPV) E2 protein plays an important role in viral DNA replication. Many studies with high-risk HPVs have demonstrated that the E2 protein can also repress transcription of the E6 and E7 oncogenes. This conclusion, based on experiments carried out with cervical cancer cells bearing integrated HPV genomes, is currently assumed to be applicable to the normal HPV life cycle, in which the viral genomes are episomal. Here, we have tested experimentally whether this assumption is correct. We made use of a pair of isogenic cell lines, W12 and S12. W12 cells contain episomal HPV16 genomes, whereas S12 cells, which are derived from the W12 line, contain HPV DNA as integrated copies. When we expressed E2 in S12 cells, we observed strong repression of E6 and E7 transcription. In contrast, no effect of E2 on the transcription of these genes was detected in W12 cells. While integration of the viral genome into the host DNA contributes to the difference between W12 and S12 cells, integration by itself is not sufficient to explain this difference. Instead, the chromatin structure in the region of the E6 and E7 promoter (p97), which we show to be very different in these two cell lines, is likely to be the cause of the different responsiveness of p97 to the E2 protein. Experiments with the histone deacetylase inhibitor trichostatin A (TSA) indicated that the episomal HPV16 DNA is in a relatively inaccessible state prior to TSA treatment. Our results, together with those of others, suggest that any effect of the E2 protein on the expression of the E6 and E7 genes during the normal viral life cycle is of secondary importance compared to the function of E2 in replication.

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