Identification Of Human Alpha-Enolase (Eno1) As An Interaction Partner Of A Brucella abortus virB Substrate

MARCHESINI M.I; MORRONE SEIJO S.; GUAIMAS F.; COMERCI D. J

Berlín

Conferencia; Brucellosis 2014 International Research Conference Including the 67th Annual Brucellosis Research Meeting; 2014

Brucellosis International Research Association

Brucella abortus, the causative agent of bovine brucellosis, invades and replicates within cells inside a membrane-bound compartment known as the Brucella containing vacuole (BCV). After trafficking along the endocytic and secretory pathways, BCVs mature in to endoplasmic reticulum (ER)-derived compartments permissive for bacterial replication .BrucellaTypeIVSecretionSystem(VirB)isamajorvirulencefactoressentialforthebiogenesisofthereplicativeorganelle.VirBsystemtranslocateseffectorproteinsthoughttomodulatehostcellsignalingpathwaystofavorintracellularsurvivalandreplication.Recently,manyVirBsubstrateshavebeenidentified.UncoveringthetargetsandfunctionsofthesetranslocatedeffectorsisessentialtounderstandtheroleofVirBinpathogenesis.BPE123(YP_418361.1)isaB.abortusVirB-translocatedeffectorproteinrecentlyidentifiedbyourgroup.Itisahypotheticalproteinwhosefunctionremainsunknown.InanattempttoidentifyhostcellproteinsinteractingwithBPE123,apull-downassaywasperformedandhumanalpha-enolasa(ENO1)wasidentifiedbyLC/MS-MSasapotentialinteractionpartnerofBPE123.Theseresultswereconfirmedbyimmunoprecipitationassays.MicroscopystudiesfurtherconfirmedBPE123-ENO1interaction:ENO1relocalizationwasdetecteduponectopicexpressionofBPE123inHeLacells,wherebothproteinslocalizedtotheER.Furthermore,duringmacrophageinfectionweobservedrecruitmentofENO1tothevicinitiesofBPE123positiveVCBs,indicatingthatinteractionwithtranslocatedBPE123mightalsobeoccurringduringtheintracellularphaseofB.abortus.Takentogether,thesepreliminaryresultssuggestadirectinteractionbetweenBPE123andENO1,amultifunctionalproteinthathasalreadybeenshowntoberequiredforBrucellareplicationinhostcells.FurtherexperimentsareunderwaytodeterminehowBPE123-ENO1interactionmodulatestheoutcomeoftheinfectionprocess.