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1.
J Sch Health ; 94(8): 687-696, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38863265

ABSTRACT

BACKGROUND: The objective of this study is to evaluate the Respect YOU program's impact on students' eating expectancies, body image satisfaction levels, self-efficacy, and knowledge. A total of 444 (intervention cohort n = 348, control cohort n = 96) underclassmen enrolled in health or physical education courses from 7 high schools in the Midwest participated in the study. METHODS: A repeated measure research design was utilized to assess students' eating expectancies, body image satisfaction levels, self-efficacy, and knowledge. More specifically, paired t-tests were conducted to compare outcome measurements to evaluate the efficacy of the intervention. RESULTS: Among the students who received the intervention (n = 348), there was a statistically significant change in scores for eating expectancies (Z = -14.403, p < .001), body image satisfaction levels (Z = -14.114, p < .001), social media self-efficacy (Z = 14.868, p < .001), and knowledge scales (Z = -16.100, p < .001) at post-intervention and compared to the control group. CONCLUSIONS: Results indicate that the Respect YOU program was effective in improving body image scores, eating expectancies, self-esteem, and knowledge-related outcomes among students post-intervention. These results can be used to further develop educational programming to address body image concerns and disordered eating among adolescents.


Subject(s)
Body Image , Curriculum , Self Efficacy , Humans , Female , Male , Pilot Projects , Adolescent , Body Image/psychology , Health Knowledge, Attitudes, Practice , Program Evaluation , Midwestern United States , Students/psychology , Feeding Behavior/psychology , Personal Satisfaction , Physical Education and Training
2.
J Proteome Res ; 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38564653

ABSTRACT

Fundamental to mammalian intrinsic and innate immune defenses against pathogens is the production of Type I and Type II interferons, such as IFN-ß and IFN-γ, respectively. The comparative effects of IFN classes on the cellular proteome, protein interactions, and virus restriction within cell types that differentially contribute to immune defenses are needed for understanding immune signaling. Here, a multilayered proteomic analysis, paired with biochemical and molecular virology assays, allows distinguishing host responses to IFN-ß and IFN-γ and associated antiviral impacts during infection with several ubiquitous human viruses. In differentiated macrophage-like monocytic cells, we classified proteins upregulated by IFN-ß, IFN-γ, or pro-inflammatory LPS. Using parallel reaction monitoring, we developed a proteotypic peptide library for shared and unique ISG signatures of each IFN class, enabling orthogonal confirmation of protein alterations. Thermal proximity coaggregation analysis identified the assembly and maintenance of IFN-induced protein interactions. Comparative proteomics and cytokine responses in macrophage-like monocytic cells and primary keratinocytes provided contextualization of their relative capacities to restrict virus production during infection with herpes simplex virus type-1, adenovirus, and human cytomegalovirus. Our findings demonstrate how IFN classes induce distinct ISG abundance and interaction profiles that drive antiviral defenses within cell types that differentially coordinate mammalian immune responses.

3.
Cell Syst ; 15(4): 339-361.e8, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38593799

ABSTRACT

The DNA-dependent protein kinase, DNA-PK, is an essential regulator of DNA damage repair. DNA-PK-driven phosphorylation events and the activated DNA damage response (DDR) pathways are also components of antiviral intrinsic and innate immune responses. Yet, it is not clear whether and how the DNA-PK response differs between these two forms of nucleic acid stress-DNA damage and DNA virus infection. Here, we define DNA-PK substrates and the signature cellular phosphoproteome response to DNA damage or infection with the nuclear-replicating DNA herpesvirus, HSV-1. We establish that DNA-PK negatively regulates the ataxia-telangiectasia-mutated (ATM) DDR kinase during viral infection. In turn, ATM blocks the binding of DNA-PK and the nuclear DNA sensor IFI16 to viral DNA, thereby inhibiting cytokine responses. However, following DNA damage, DNA-PK enhances ATM activity, which is required for IFN-ß expression. These findings demonstrate that the DDR autoregulates cytokine expression through the opposing modulation of DDR kinases.


Subject(s)
Ataxia Telangiectasia , Herpesviridae Infections , Humans , Phosphorylation , DNA-Activated Protein Kinase/genetics , DNA-Activated Protein Kinase/metabolism , Cytokines/metabolism , Ataxia Telangiectasia Mutated Proteins/genetics , Ataxia Telangiectasia Mutated Proteins/metabolism , DNA Damage
4.
Nat Methods ; 21(3): 488-500, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38361019

ABSTRACT

Protein-protein interactions (PPIs) drive cellular processes and responses to environmental cues, reflecting the cellular state. Here we develop Tapioca, an ensemble machine learning framework for studying global PPIs in dynamic contexts. Tapioca predicts de novo interactions by integrating mass spectrometry interactome data from thermal/ion denaturation or cofractionation workflows with protein properties and tissue-specific functional networks. Focusing on the thermal proximity coaggregation method, we improved the experimental workflow. Finely tuned thermal denaturation afforded increased throughput, while cell lysis optimization enhanced protein detection from different subcellular compartments. The Tapioca workflow was next leveraged to investigate viral infection dynamics. Temporal PPIs were characterized during the reactivation from latency of the oncogenic Kaposi's sarcoma-associated herpesvirus. Together with functional assays, NUCKS was identified as a proviral hub protein, and a broader role was uncovered by integrating PPI networks from alpha- and betaherpesvirus infections. Altogether, Tapioca provides a web-accessible platform for predicting PPIs in dynamic contexts.


Subject(s)
Herpesvirus 8, Human , Manihot , Sarcoma, Kaposi , Sarcoma, Kaposi/metabolism , Viral Proteins/metabolism , Manihot/metabolism , Virus Latency , Herpesvirus 8, Human/metabolism
5.
J Am Coll Health ; : 1-8, 2022 Oct 25.
Article in English | MEDLINE | ID: mdl-36282209

ABSTRACT

Objective: The purpose of this study is to examine the attitudes and perceptions of college undergraduates regarding cannabis vaping. Participants: Twenty-one, predominantly male (71.4%; Mage = 22, SD = 2.09), undergraduate college students who reported vaping cannabis in the past 30 days. Methods: Participants were interviewed to determine their attitudes and perceptions regarding cannabis vaping. Findings: Thematic analysis uncovered six primary themes and eighteen subthemes. Main themes included (1) Convenience, (2) Discreetness, (3) Mood-Altering Experience, (4) Social Acceptability, (5) Health and Safety, and (6) COVID-19 Pandemic Impact. Conclusion: College students who use cannabis tend to both vape and use combustible methods, depending upon social and physical environment. This population tends to vaporize cannabis for its perceived mood-altering properties. Additional research is needed to further examine the behaviors and attitudes surrounding cannabis vaping among college undergraduates, as well as the development of interventions specific to this demographic.

6.
J Am Coll Health ; 70(4): 1195-1203, 2022.
Article in English | MEDLINE | ID: mdl-32673177

ABSTRACT

ObjectiveSince the late '90 s, energy drink consumption has increased. The purpose of this investigation was to examine energy drink expectancies of college students. Participants: The university registrar randomly selected fifty university classes to be surveyed. Methods: A cross-sectional research design was used to assess the prevalence of energy drink consumption and energy drink expectancies. Binary logistic regression analyses were conducted to ascertain which expectancies explained energy drink consumption. Results: The expectancy factors of 1,246 participants accounted for 25.8% of the variance in past 30-day energy drink consumption. Energy enhancement, anxiety/negative physical effects, withdrawal, and appetite suppression were each found to be significantly related to energy drink consumption. Conclusions: Energy enhancement and anxiety/negative effects were the strongest predictors of energy drink consumption among college students. The results from this study can be used to design interventions to challenge erroneous expectancies and reinforce others that promote moderation or abstinence.


Subject(s)
Energy Drinks , Cross-Sectional Studies , Humans , Students , Surveys and Questionnaires , Universities
7.
ACS Synth Biol ; 8(12): 2651-2658, 2019 12 20.
Article in English | MEDLINE | ID: mdl-31742389

ABSTRACT

Microbially produced protein-based materials (PBMs) are appealing due to use of renewable feedstock, low energy requirements, tunable side-chain chemistry, and biodegradability. However, high-strength PBMs typically have high molecular weights (HMW) and repetitive sequences that are difficult to microbially produce due to genetic instability and metabolic burden. We report the development of a biosynthetic strategy termed seeded chain-growth polymerization (SCP) for synthesis of HMW PBMs in living bacterial cells. SCP uses split intein (SI) chemistry to cotranslationally polymerize relatively small, genetically stable material protein subunits, effectively preventing intramolecular cyclization. We apply SCP to bioproduction of spider silk in Escherichia coli, generating HMW spider silk proteins (spidroins) up to 300 kDa, resulting in spidroin fibers of high strength, modulus, and toughness. SCP provides a modular strategy to synthesize HMW, repetitive material proteins, and may facilitate bioproduction of a variety of high-performance PBMs for broad applications.


Subject(s)
Escherichia coli/metabolism , Fibroins/biosynthesis , Microbial Viability , Polymerization , Biopolymers/biosynthesis , Fibroins/chemistry , Fibroins/ultrastructure , Inteins/genetics , Molecular Weight , Protein Structure, Secondary , Reproducibility of Results
9.
J Am Coll Health ; 67(8): 743-752, 2019.
Article in English | MEDLINE | ID: mdl-30240330

ABSTRACT

Objective: With medical and recreational marijuana legislation expanding throughout the country, the need to educate high-risk populations is evident. The purpose of this study was to assess college students' perceptions of health communication messages comparing primary and secondary prevention messages concerning marijuana. Participants: Participants (n = 487) included college students, ages 18-25, enrolled in a Midwestern University. Methods: Participants assessed messages based on likeability, creativity, believability, persuasiveness, relevance, and usefulness using an online questionnaire that also included open-end comments. Results: Rasch analyses indicate that nonmarijuana users rated primary prevention messages higher than secondary prevention messages, whereas marijuana users ranked secondary prevention messages more favorably than primary prevention messages. Conclusion: Interventions designed to address marijuana use among college students may be more effective if tailored toward user status. Specifically, primary prevention materials should be designed for abstainers, while secondary prevention messages that focus on harm reduction strategies should be used with marijuana users.


Subject(s)
Health Promotion/methods , Marijuana Smoking/prevention & control , Marijuana Smoking/psychology , Marijuana Use/psychology , Primary Prevention/methods , Secondary Prevention/statistics & numerical data , Students/psychology , Adolescent , Adult , Communication , Female , Health Promotion/statistics & numerical data , Humans , Male , Midwestern United States , Primary Prevention/statistics & numerical data , Risk Factors , Secondary Prevention/methods , Students/statistics & numerical data , Surveys and Questionnaires , Universities/statistics & numerical data , Young Adult
10.
Health Promot Pract ; 19(2): 175-183, 2018 03.
Article in English | MEDLINE | ID: mdl-28950728

ABSTRACT

BACKGROUND: Water-related injuries and fatalities pose serious public health issues, especially to African American youth, a demographic group that drowns at disproportionately high rates. AIM: The purpose of this study was to determine if a social marketing intervention targeting the parents and guardians of inner-city youth (U.S. Midwest) could positively influence their perceptions concerning water safety. METHOD: Researchers employed a quasi-experimental design using matched pairs to evaluate the intervention. Participants consisted of parents who enrolled their children in a six-session survival-swimming course. Guided by the Health Belief Model, the researchers disseminated six prevention messages using six different channels (brochure, e-mail, SMS text message, postcard, Facebook, and window cling). RESULTS: The findings from a two-way analysis of covariance revealed that treatment group participants' knowledge and perceptions of water-related threat all changed favorably. Additionally, all participants planned to reenroll their children in swim lessons. DISCUSSION: A social marketing campaign using the Health Belief Model improved inner-city parents' knowledge regarding water safety and enhanced their self-efficacy. CONCLUSION: This study provides practitioners with feasible strategies (prevention messages) to supplement swim lessons, with the ultimate goal of preventing drowning among at-risk youth.


Subject(s)
Drowning/prevention & control , Social Marketing , Adolescent , Child , Cities , Health Promotion/methods , Humans , Midwestern United States , Program Evaluation , Surveys and Questionnaires
11.
Org Biomol Chem ; 16(1): 62-69, 2017 Dec 19.
Article in English | MEDLINE | ID: mdl-29098212

ABSTRACT

3,7-Dihydroxytropolones (3,7-dHTs) are highly oxygenated troponoids that have been identified as lead compounds for several human diseases. To date, structure-function studies on these molecules have been limited due to a scarcity of synthetic methods for their preparation. New synthetic strategies towards structurally novel 3,7-dHTs would be valuable in further studying their therapeutic potential. Here we describe the successful adaptation of a [5 + 2] oxidopyrilium cycloaddition/ring-opening for 3,7-dHT synthesis, which we apply in the synthesis of a plausible biosynthetic intermediate to the natural products puberulic and puberulonic acid. We have also tested these new compounds in several biological assays related to human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV) in order to gain insight into structure-functional analysis related to antiviral troponoid development.


Subject(s)
Antiviral Agents/pharmacology , HIV/drug effects , Hepatitis B virus/drug effects , Simplexvirus/drug effects , Tropolone/analogs & derivatives , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Dose-Response Relationship, Drug , Microbial Sensitivity Tests , Molecular Structure , Structure-Activity Relationship , Tropolone/chemical synthesis , Tropolone/chemistry , Tropolone/pharmacology
12.
J Viral Hepat ; 21(12): 882-93, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24401091

ABSTRACT

Hepatitis B virus (HBV) antiviral therapy is plagued by limited efficacy and resistance to most nucleos(t)ide analog drugs. We have proposed that the complex RNA binding mechanism of the HBV reverse transcriptase (P) may be a novel target for antivirals. We previously found that RNA binds to the duck HBV (DHBV) P through interactions with the T3 and RT1 motifs in the viral terminal protein and reverse transcriptase domains, respectively. Here, we extended these studies to HBV P. HBV T3 and RT1 synthetic peptides bound RNA in a similar manner as did analogous DHBV peptides. The HBV T3 motif could partially substitute for DHBV T3 during RNA binding and DNA priming by DHBV P, whereas replacing RT1 supported substantial RNA binding but not priming. Substituting both the HBV T3 and RT1 motifs restored near wild-type levels of RNA binding but supported very little priming. Alanine-scanning mutations to the HBV T3 and RT1 motifs blocked HBV ε RNA binding in vitro and pgRNA encapsidation in cells. These data indicate that both the HBV T3 and RT1 motifs contain sequences essential for HBV ε RNA binding and encapsidation of the RNA pregenome, which is similar to their functions in DHBV. Small molecules that bind to T3 and/or RT1 would therefore inhibit encapsidation of the viral RNA and block genomic replication. Such drugs would target a novel viral function and would be good candidates for use in combination with the nucleoside analogs to improve efficacy of antiviral therapy.


Subject(s)
Gene Products, pol/metabolism , Hepatitis B virus/enzymology , Hepatitis B virus/physiology , RNA, Viral/metabolism , Virus Assembly , Amino Acid Substitution , Cell Line , DNA Mutational Analysis , Gene Products, pol/genetics , Hepatocytes/virology , Humans , Protein Binding , Virus Replication
13.
J Am Coll Health ; 59(8): 764-8, 2011.
Article in English | MEDLINE | ID: mdl-21950260

ABSTRACT

This report examines the rationale for creating a tobacco-free campus to utilize in passing antitobacco policies, and recommendations for overcoming barriers. As with any type of advocacy effort, a variety of impediments exist, including lack of administrative and staff support, absence of student involvement, and sparse resources. A variety of potential remedies and advocacy opportunities are explored and delineated.


Subject(s)
Health Promotion/legislation & jurisprudence , Nicotiana , Organizational Policy , Smoking Cessation , Smoking Prevention , Universities/legislation & jurisprudence , Health Status Disparities , Humans , Smoking/epidemiology , Students , United States/epidemiology
14.
J Viral Hepat ; 18(5): 349-57, 2011 May.
Article in English | MEDLINE | ID: mdl-20529202

ABSTRACT

The hepatitis C virus (HCV) RNA polymerase (RdRp) may be a target of the drug ribavirin, and it is an object of drug development. Independent isolates of any HCV subtype differ genetically by approximately 10%, but the effects of this variation on enzymatic activity and drug sensitivity are poorly understood. We proposed that nucleotide use profiles (G/U ratio) among subtype 1b RdRps may reflect their use of ribavirin. Here, we characterized how subtype 1b genetic variation affects RNA polymerase activity and evaluated the G/U ratio as a surrogate for ribavirin use during pegylated interferon α and ribavirin therapy. Genetic and biochemical variation in the RdRp was compared between responders who would be largely sensitive to ribavirin and relapsers who would be mostly resistant. There were no consistent genetic differences between responder and relapser RdRps. RNA polymerization, RNA binding and primer usage varied widely among the RdRps, but these parameters did not differ significantly between the response groups. The G/U ratio among a set of subtype 1a RdRps increased rather than decreased following failed therapy, as would be expected if it reflected ribavirin use. Finally, RdRp activity was significantly associated with ALT levels. These data indicate that (i) current genetic approaches cannot predict RNA polymerase behaviour, (ii) the G/U ratio is not a surrogate for ribavirin use, (iii) RdRp activity may contribute to liver disease by modulating viral mRNA and antigen levels, and (iv) drug candidates should be tested against multiple patient-derived enzymes to ensure widespread efficacy even within a viral subtype.


Subject(s)
Antiviral Agents/therapeutic use , DNA-Directed RNA Polymerases/drug effects , Hepacivirus/drug effects , Hepatitis C/drug therapy , Viral Nonstructural Proteins/metabolism , Antiviral Agents/administration & dosage , Antiviral Agents/pharmacology , DNA-Directed RNA Polymerases/genetics , DNA-Directed RNA Polymerases/metabolism , Drug Therapy, Combination , Genetic Variation/genetics , Hepacivirus/enzymology , Hepacivirus/genetics , Hepatitis C/virology , Humans , Interferon-alpha/administration & dosage , Interferon-alpha/pharmacology , Interferon-alpha/therapeutic use , RNA, Viral/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Recurrence , Ribavirin/administration & dosage , Ribavirin/pharmacology , Ribavirin/therapeutic use , Viral Nonstructural Proteins/genetics
15.
J Am Coll Health ; 58(5): 413-23, 2010.
Article in English | MEDLINE | ID: mdl-20304753

ABSTRACT

UNLABELLED: Alcohol use and the related consequences associated with college football games are a serious public health issue for university communities. OBJECTIVE: Examining "Extreme Ritualistic Alcohol Consumption" (ERAC), defined as consuming 10 or more drinks on game day for a male, and 8 or more drinks for a female, is the focus of this study. PARTICIPANTS: In the fall of 2006, college students ages 18 to 24 were randomly selected to complete the Game Day Survey. METHODS: Researchers utilized a cross sectional research design to collect data. RESULTS: Sixteen percent of the respondents engaged in ERAC on game day, whereas 36% drank 5 or more drinks (4 or more for females). Male, Caucasian, Greek (members of a social fraternity or sorority), and students of legal drinking age consumed alcohol at disproportionately high rates. CONCLUSION: Alcohol use is common on game day, with a significant percentage of students placing themselves at risk by drinking large amounts of alcohol.


Subject(s)
Alcoholic Intoxication/epidemiology , Alcoholism/epidemiology , Ceremonial Behavior , Risk-Taking , Sports/statistics & numerical data , Universities/statistics & numerical data , Adolescent , Age Factors , Confidence Intervals , Cross-Sectional Studies , Data Collection , Female , Florida/epidemiology , Humans , Male , Odds Ratio , Peer Group , Risk Factors , Sex Factors , Statistics as Topic , Students/psychology , Students/statistics & numerical data , Surveys and Questionnaires , Young Adult
16.
J Viral Hepat ; 16(8): 595-604, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19243495

ABSTRACT

Hepatitis C virus (HCV) infections are treated with interferon alpha plus ribavirin, but it is unknown how ribavirin works against HCV. Ribavirin is a guanosine analogue that can be a substrate for the viral RNA polymerase. HCV is genetically variable, and this genetic variation could affect the polymerase's use of ribavirin triphosphate. Thirteen patients infected with HCV who failed interferon alpha monotherapy and were retreated with interferon alpha plus ribavirin were identified; seven were responders and six were nonresponders to combination therapy. The consensus sequences encoding the 13 polymerases plus seven sequences from treatment-naive controls were determined. The responder sequences were more genetically variable than the nonresponders and controls, the amino acid variations unique to responders had lower BLOSUM90 scores than variations in nonresponders and controls, and the amino acid variations correlated with response to therapy clustered around the RNA-binding channel of the polymerase. These data imply that that the responder enzymes were probably more functionally variable than the nonresponder enzymes. Enzymatic activity was measured for 10 recombinant polymerases; RNA synthesis activity varied by over sevenfold and polymerases from two of the responders used GTP much better than UTP, but technical limitations prevented direct measurement of ribavirin triphosphate use. Because response to combination therapy in these patients was primarily due to addition of ribavirin to the treatment regimen, these data imply that genetic variation in the polymerase may have affected the efficiency of ribavirin incorporation into the viral genome and hence may have modulated ribavirin's efficacy against HCV.


Subject(s)
Antiviral Agents/pharmacology , DNA-Directed RNA Polymerases/metabolism , Hepacivirus/drug effects , Ribavirin/pharmacology , Viral Proteins/metabolism , Amino Acid Sequence , DNA-Directed RNA Polymerases/genetics , Genetic Variation , Hepatitis C, Chronic/drug therapy , Humans , Models, Molecular , Molecular Sequence Data , Mutation, Missense , Protein Structure, Tertiary , RNA, Viral/biosynthesis , Ribavirin/therapeutic use , Sequence Alignment , Sequence Analysis, DNA , Viral Proteins/genetics
17.
J Pediatr Surg ; 38(5): 788-92, 2003 May.
Article in English | MEDLINE | ID: mdl-12720195

ABSTRACT

PURPOSE: Pediatric central venous catheters (CVCs) traditionally have been placed surgically, guided by anatomic landmarks. Increasingly, interventional radiology services are inserting CVCs using ultrasound image guidance. This study compares the frequency of delayed complications in CVCs placed surgically or radiologically in a pediatric oncology population. METHODS: Data on CVCs placed in one academic institution over 10 years were collected and analyzed retrospectively. Main outcomes assessed were infectious complications, mechanical complications, and premature catheter removal. RESULTS: Ninety-eight CVCs-comprising 52 external tunneled catheters (ETCs) and 46 subcutaneous ports-were assessed in 67 patients. Median patient age was 6.1 years for children with external catheters and 7.8 years for those with ports. Both infectious and mechanical complications were significantly more common among surgically placed ETCs than those placed radiologically (P <.05). Complications per 1,000 catheter days and premature removal showed a trend toward greater frequency among surgical ETCs, although this did not reach statistical significance. No consistent trends were seen in complications among ports. CONCLUSIONS: Pediatric patients with CVCs, especially those with external catheters, experience frequent delayed complications. Patients with radiologically inserted ETCs may encounter fewer complications than those with surgically placed ones. This corroborates previous reports in the literature suggesting image-guided CVC placement as a preferable alternative to traditional techniques.


Subject(s)
Catheterization, Central Venous/adverse effects , Catheterization, Central Venous/methods , Catheters, Indwelling/adverse effects , Child , Child, Preschool , Female , General Surgery , Humans , Male , Radiology, Interventional , Retrospective Studies , Ultrasonography
18.
J Virol ; 75(22): 10721-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11602713

ABSTRACT

The VP22 protein of herpes simplex virus type 2 (HSV-2) is a major component of the virion tegument. Previous work with HSV-1 indicated that VP22 is phosphorylated during infection, and phosphorylation may play a role in modulating VP22 localization in infected cells. It is not clear, however, when phosphorylation occurs in infected cells or how it is regulated. Less is known about the synthesis and phosphorylation of HSV-2 VP22. To study the complete biosynthetic history of HSV-2 VP22, we generated a monoclonal antibody to the carboxy terminus of VP22. Using immunoprecipitation and Western blot analyses, we show that HSV-2 VP22 can be found in three distinct isoforms in infected cells, two of which are phosphorylated. Like HSV-1 VP22, HSV-2 VP22 is synthesized ca. 4 h after infection, and the isoform later incorporated into virions is hypophosphorylated. In addition, we demonstrate for the first time (i) that newly synthesized VP22 is phosphorylated rapidly after synthesis, (ii) that this phosphorylation occurs in a virus-dependent manner, (iii) that the HSV-2 kinase UL13 is capable of inducing phosphorylation of VP22 in the absence of other viral proteins, (iv) that phosphorylated VP22 is very stable in infected cells, (v) that phosphorylated isoforms of VP22 are gradually dephosphorylated late in infection to produce the virion tegument form, and (vi) that this dephosphorylation occurs independently of viral DNA replication or virion assembly. These results indicate that HSV-2 VP22 is a stable protein that undergoes highly regulated, virus-dependent phosphorylation events in infected cells.


Subject(s)
Herpesvirus 2, Human/metabolism , Viral Structural Proteins/metabolism , Animals , Antibodies, Monoclonal/immunology , Chlorocebus aethiops , Herpesvirus 2, Human/pathogenicity , Phosphorylation , Protein Isoforms , Protein Kinases/physiology , Transfection , Vero Cells , Viral Structural Proteins/analysis , Viral Structural Proteins/immunology
19.
BMC Microbiol ; 1: 12, 2001.
Article in English | MEDLINE | ID: mdl-11504562

ABSTRACT

BACKGROUND: The hepadnaviral reverse transcriptase can synthesize DNA on its native RNA template within viral cores but it is usually unable to synthesize DNA employing exogenous nucleic acids as a template. The mechanism of this template commitment is unknown. Here we provide evidence that the RNAseH activity of duck hepatitis B virus reverse transcriptase may also be unable to act on exogenous substrates. RESULTS: RNAseH assays were performed under a wide variety of conditions employing substrate RNAs of Duck Hepatitis B Virus sequence annealed to complementary DNA oligonucleotides and permeabilized intracellular viral core particles. Temperature, pH, cation type, salt concentration, substrate concentration, and the sequences of the cleavage sites were varied, and the effects of ATP and dNTPs on RNAseH activity were examined. duck hepatitis B virus RNAseH activity was not detected under any of these conditions, although E. coli or Avian Myeloblastosis Virus RNAseH activity could be detected under all conditions. Access of the RNA substrate to the enzyme within the viral cores was confirmed. CONCLUSIONS: These results imply that the RNAseH activity of the DHBV reverse transcriptase may not be able to degrade exogenous RNA:DNA heteroduplexes, although it can degrade heteroduplexes of the same sequence generated during reverse transcription of the endogenous RNA template. Therefore, the RNAseH activity appears to be "substrate committed" in a manner similar to the template commitment observed for the DNA polymerase activity.


Subject(s)
Hepatitis B Virus, Duck/enzymology , Ribonuclease H/metabolism , Oligonucleotides/metabolism , RNA-Directed DNA Polymerase/metabolism , Substrate Specificity
20.
J Virol ; 74(18): 8648-57, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10954566

ABSTRACT

The hepadnavirus reverse transcriptase binds cotranslationally to the viral pregenomic RNA. This ribonucleoprotein complex is then encapsidated into nascent viral core particles, where the reverse transcriptase copies the viral RNA into DNA. Here we report that 75% of the duck hepatitis B virus reverse transcriptase present in transfected LMH cells does not follow this well-known pathway but rather exists in the cell separate from the core protein or nucleocapsids. The nonencapsidated reverse transcriptase is also abundant in infected duck liver. The nonencapsidated reverse transcriptase exists as a complex set of isoforms that are most likely produced by posttranslational modification. Interestingly, only the smallest of these isoforms is encapsidated into viral core particles. The nonencapsidated reverse transcriptase is bound to a large cellular cytoplasmic structure(s) in a detergent-sensitive complex. The cellular distribution of the reverse transcriptase only partially overlaps that of the core protein, and this distribution is unaffected by blocking encapsidation. These observations raise the possibilities that the metabolic fate of the reverse transcriptase may be posttranscriptionally regulated and that the reverse transcriptase may have roles in the viral replication cycle beyond its well-known function in copying the viral genome.


Subject(s)
Capsid/metabolism , Cytoplasm/virology , Hepadnaviridae Infections/veterinary , Hepatitis B Virus, Duck/metabolism , Poultry Diseases/virology , RNA-Directed DNA Polymerase/metabolism , Animals , Blotting, Western , Cell Fractionation , Chickens , Detergents/pharmacology , Ducks , Fluorescent Antibody Technique , Hepadnaviridae Infections/enzymology , Hepadnaviridae Infections/virology , Hepatitis B Virus, Duck/isolation & purification , Liver/enzymology , Liver/virology , Microscopy, Confocal , Poultry Diseases/enzymology , Precipitin Tests , RNA-Directed DNA Polymerase/isolation & purification , Sodium Dodecyl Sulfate/pharmacology , Tumor Cells, Cultured
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