Influenzavirusisaseriouspublichealththreatcausingsignificantmorbidityandmortality.Seasonalinfections are punctuated by pandemic outbreaks with the potential for widespread infection and disease. This is exemplifiedbytheemergenceofthe2009H1N1pandemicvirusthatrapidlybecamethedominantcirculating strain.Inspiteofthisrisk,thereareonlytwomainclassesofapprovedantivirals,andonlytheneuraminidase inhibitors are efficacious against currently circulating strains. There is a clear need for the discovery of new antiviral therapies and the identification of novel antiviral targets. The influenza virus polymerase is an attractive target for antiviral development. The polymerase assembles with genomic RNA and the viral nucleoprotein(NP)toformlargeribonucleoprotein(RNP)complexes.TheRNPsmediatebothtranscriptionof viralmRNAandreplicationoftheviralgenome.RNPassemblyandpolymeraseactivityareessentialforviral replication, yet how these events are regulated has long remained unclear. We have generated data suggesting that post-translational modifications of NP and the viral polymerase dynamically regulate the formationofRNPs,andtheresultantsynthesisofviralRNAs.Theoverallgoalofthisproposalistounderstand howpost-translationalmodificationsregulateinfluenzavirusRNPassemblyandpolymeraseactivity.Ourfirst objective (Aim 1) is to establish the mechanisms by which phosphorylation regulates NP oligomerization. TheseexperimentsidentifyhostkinasesandphosphatasesthatregulateNPphosphorylationanddemonstrate howthiscontrolsthetransitionofNPfromamonomertothehigher-orderoligomerpresentintheRNP.Wewill alsodefinethetemporalpatternsofNPphosphorylationandhowtheseimpactthetransitionfromtranscription ofviralmRNAstoreplicationoftheviralgenome.Oursecondobjective(Aim2)istodeterminethefunctional consequencesofnovelpost-translationalmodificationswerecentlyidentifiedontheviralpolymeraseandNP. Experiments will determine the host factors mediating this modification and the biological impact during infections.CompletionofthisaimwilldefineacompletelynewregulatorymechanismcontrollingRNPactivity. Theresultsfromthisproposalwillestablishamechanisticunderstandingoftheviralandhostfactorsregulating assembly and function of the RNP and identify exciting new targets that can be exploited for the rational developmentofanti-influenzavirustherapies.

Public Health Relevance

The influenza virus replication machinery is a key player in establishing infection and determining its pathogenicity. These studies will provide insight into the viral and host factors that regulate the influenza replication machinery, how it controls viral replication, and may ultimately identify new targets for therapeutic intervention.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI125271-02
Application #
9285698
Study Section
Virology - A Study Section (VIRA)
Program Officer
Hauguel, Teresa M
Project Start
2016-06-06
Project End
2021-05-31
Budget Start
2017-06-01
Budget End
2018-05-31
Support Year
2
Fiscal Year
2017
Total Cost
$379,320
Indirect Cost
$129,320
Name
University of Wisconsin Madison
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
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