SARS Coronavirus 3b Accessory Protein Modulates Transcriptional Activity of RUNX1b.docx
SARSCoronavirus3bAccessoryProteinModulatesTranscriptionalActivityofRUNXlbSAKSCoronavirus3bzccessoryProteinModlatesTranscriptionalActiviIyofRUNX1bBhavnaVarshney1 ,SudhakarAgnihotram2,Yee-JooTan3,KalphBaric2 ,SunilK.1.al1*IvirologyGroup,InternationalCentreforGeneticEngineeringandBiotechnology,NewDelhi,India,2DepartmentofMiCrobiologyandImmunology,UniversityofNorthCarolina,ChapelHill,NorthCarolina,UnitedStatesofAmerica,3DepartmentofMicrobiology,Yong1.oo1.inSchoolofMedicine,NationalUniversityofSingapore,Singapore,SingaporeAbstractBackground:Thecausativeagentofsevereacuterespiratorysyndrome,SARScoronavirus(SARS-CoV)genomeencodesseveraluniquegropspecificaccessoryproteinswithnknownfunctions.Amongthem,accessoryprotein3b(alsoknownasORF4)waslatelyidentifiedasoneoftheViralinterferonantagonist.Recentlyourlabuncoveredanewrolefor3binUpregulationofAp-Itranscriptionalactivityanditsdownstreanigenes.Thus,WebelievethatBbmightplayanimportantroleinSRS-CoVpatHogenesisandtKereforeisofconsiderableinterest.ThecurrentstudyaimsatidentifyingnovelhostCellularinteractorsoftheSbprotein.Methodology/PrincipalFindings:Inthisstudy,usingyeasttwo-hybridandco-immunoprecipitationtechniqucs,WChaVeidentifiedahosttranscriptIonfactorRUNXlb(RuntreIatedtranscriptionfactor,isoformb)asanovelinteractingpartnerforSRSCoV3bprotein.Chromatinimmunoprecipitaion(ChIP)andreportergcncassaysin3bexpressingjurkatcelIsshowedrccruitmcntof3bonthcRUNXIbindinge1cmcnIthatledtoanincreaseiIiRUNXlbtransactivationpotentialontheI1.2promoter.KinaseassayandpharmacologicalinhibiIortreatmentimpIiedthatBbalsoaffectRuNxibtranscriptionalactivitybyregulatingitsERKdependentphosphorylationlevels.Additionally,mRNlevelsofMIP-IataRUNXlbtargetgeneUpregulatedinSARS-CoVinfectedmonocytederiveddendriticcells,werefoundtobeelevatedin3bexpressingU937monocyIecelIs.Conclusions/Significanoe:Theseresultsunveilanove1interactionofSARS-CoV3bwiththehostfactor,RUNXlb,andspeculateitsphysiologicalrclevanceinupregulatingcytokineSandchemokinelevelsinstat.