treatmentvpsmm

Pathogens2013,2,457-471;doi:10.
3390/pathogens2030457pathogensISSN2076-0817www.
mdpi.
com/journal/pathogensReviewPrionsinVariablyProtease-SensitivePrionopathy:AnUpdateWen-QuanZou1,2,3,4,5,6,*,PierluigiGambetti1,3,XiangzhuXiao1,JueYuan1,JanLangeveld7andLauraPirisinu81DepartmentofPathologyCaseWesternReserveUniversitySchoolofMedicine,Cleveland,OH44106,USA;E-Mails:pxg13@case.
edu(P.
G.
);xiangzhu.
xiao@case.
edu(X.
X.
);jue.
yuan@case.
edu(J.
Y.
)2DepartmentofNeurology,CaseWesternReserveUniversitySchoolofMedicine,Cleveland,OH44106,USA3NationalPrionDiseasePathologySurveillanceCenter,CaseWesternReserveUniversitySchoolofMedicine,Cleveland,OH44106,USA4NationalCenterforRegenerativeMedicine,CaseWesternReserveUniversitySchoolofMedicine,Cleveland,OH44106,USA5TheFirstAffiliatedHospital,NanchangUniversity,Nanchang330006,JiangxiProvince,China6StateKeyLaboratoryforInfectiousDiseasePreventionandControl,NationalInstituteforViralDiseaseControlandPrevention,ChineseCenterforDiseaseControlandPrevention,Beijing100050,China7CentralVeterinaryInstituteofWageningenUR,Lelystad8200AB,theNetherlands;E-Mail:jan.
langeveld@wur.
nl(J.
L.
)8DepartmentofVeterinaryPublicHealthandFoodSafety,IstitutoSuperiorediSanità,VialeReginaElena29900161,Rome,Italy;E-Mail:laura.
pirisinu@guest.
iss.
it(L.
P.
)*Authortowhomcorrespondenceshouldbeaddressed;E-Mail:wenquan.
zou@case.
edu;Tel.
/Fax:+1-216-368-8993/+1-216-368-2546.
Received:12June2013;inrevisedform:28June2013/Accepted:2July2013/Published:5July2013Abstract:Humanpriondiseases,includingsporadic,familial,andacquiredformssuchasCreutzfeldt-Jakobdisease(CJD),arecausedbyprionsinwhichanabnormalprionprotein(PrPSc)derivedfromitsnormalcellularisoform(PrPC)istheonlyknowncomponent.
Therecently-identifiedvariablyprotease-sensitiveprionopathy(VPSPr)ischaracterizednotonlybyanatypicalclinicalphenotypeandneuropathologybutalsobythedepositioninthebrainofapeculiarPrPSc.
Likeotherformsofhumanpriondisease,thepathogenesisofVPSPralsocurrentlyremainsunclear.
However,thefindingsofthepeculiarfeaturesofOPENACCESSPathogens2013,2458prionsfromVPSPrandofthepossibleassociationofVPSPrwithaknowngeneticpriondiseaselinkedwithavalinetoisoleucinemutationatresidue180ofPrPreportedrecently,maybeofgreatimportanceinenhancingourunderstandingofnotonlythisatypicalhumanpriondiseaseinparticular,butalsootherpriondiseasesingeneral.
Inthisreview,wehighlightthephysicochemicalandbiologicalpropertiesofprionsfromVPSPranddiscussthepathogenesisofVPSPrincludingtheoriginandformationofthepeculiarprions.
Keywords:prions;prionprotein;priondisease;Creutzfeldt-Jakobdisease(CJD);variablyprotease-sensitiveprionopathy(VPSPr);Gerstmann-Strussler-Scheinker(GSS);mutation;proteinaseK;antibody;glycosylation;glycoform-selectiveprionformation;transmissibility1.
IntroductionPrionsareinfectiouspathogensthatareassociatedwithagroupoffataltransmissiblespongiformencephalopathiesorpriondiseasesaffectingbothanimalsandhumans.
Theyarecomposedmainly,ifnotentirely,ofthepathologicscrapieconformer(PrPSc)andoriginatefromthecellularprionprotein(PrPC)bymeansofastructuraltransitionfromalargelyα-helicalformtopredominantlyβ-sheets[1].
Unlikeotherinfectiousagents,suchasbacteria,viruses,andfungi,whichcontaingenomescomposedofeitherDNAorRNA,prionsaretheonlyknowninfectiouspathogensthataredevoidofnucleicacid,accordingtothe"proteinonly"hypothesis[1].
Humanpriondiseasesarehighlyheterogeneous:Theycanbefamilial,sporadic,oracquiredbyinfection,andincludeCreutzfeldt-Jakobdisease(CJD),Gerstmann-Strussler-Scheinker(GSS)disease,fatalinsomnia,kuruandvariantCJD(vCJD)[2].
Atypicalhumanandanimalpriondiseaseshaverecentlybeenidentifiedincludingvariablyprotease-sensitiveprionopathy(VPSPr)inhumanandNor98/atypicalscrapieinsheepandgoats[3–7].
Thetwoatypicalhumanandsheeppriondiseasesarecharacterizedbythedepositionofpeculiarprionsinthebrain.
Nomutationshavebeenfoundintheopenreadingframeofprionproteingeneinthetwodiseases.
WhileNor98scrapieisassociatedwithpolymorphismsatR154HandL141F,VPSPrisobservedinallthreegenotypesofPrPpolymorphismatresidue129ofPrP.
PrPScfromthetwodiseasesexhibitedasmallPK-resistantfragmentsimilartothoseobservedinsomeoffamilialpriondiseases[4–6,8].
2.
DominantProtease-SensitivePrPScConformerIntheelevencasesfirstreported,theywereallvaline/valinehomozygosityatresidue129ofPrPandmorethanhalfofthemhadafamilyhistoryofdementia[4].
AlthoughspongiformdegenerationandPrPimmunostainingwereobserved,surprisingly,notypicalPK-resistantPrPSc(rPrPSc)wasdetectableinthebrainofallcasesbyconventionalWesternblottingprobingwiththewidely-usedanti-PrPantibody3F4.
The3F4antibodythathasanepitopebetweenresidues106and112[9]detectedanabnormalPrPinPSPronlyafterenrichmentwithgene5protein(g5p)andsodiumphosphotungstate(NaPTA)thatareabletobindtoabnormally-foldedPrPmoleculesregardlessoftheirPKresistance[10,11].
However,morethan70%oftheabnormalPrPcapturedbyg5pfromthesecaseswassensitivetoPK-digestionwhileonlyabout10%ofcapturedPrPScwasPK-sensitiveinsCJD.
Therefore,thisatypicalhumanpriondiseasecharacterizedbythedepositioninthebrainofdominantPK-sensitivePrPSc(sPrPSc)wasinitiallytermedasprotease-sensitiveprionopathy(PSPr)[4].
Pathogens2013,2459Figure1.
DetectionofPrPfromvariablyprotease-sensitiveprionopathy(VPSPr),Gerstmann-Strussler-Scheinker(GSS),andsporadicCreutzfeldt-Jakobdisease(sCJD)with129methionine/methionine(MM)polymorphismandPrPSctype1(sCJDMM1)withnineanti-PrPantibodies.
A:Diagramofepitopelocationsofanti-PrPantibodiesexaminedonhumanPrP.
Antibodiesandtheirepitopesare:3F4(PrP106-112),1E4(PrP97-105),6D11(PrP93-109),8G8(PrP95-110),Anti-C(PrP220-231),6H4(PrP145-152),9A2(PrP99-101),12B2(PrP89-93),andV14(PrP185-196).
BthroughJ:BrainhomogenatesfromVPSPr,GSSlinkedtoPrPP1°2Lmutation(GSS102),GSSlinkedtoPrPA117Vmutation,andsCJDMM1weretreatedwithPKor/PNGaseFpriortoSDS-PAGEandWesternblottingwithninedifferentanti-PrPantibodies,respectively.
B:3F4;C:1E4;D:6D11;E:8G8;F:Anti-C;G:6H4;H:9A2;I:12B2;J:V14.
Ofthenineantibodiesused,1E4exhibitsthehighestaffinityforrPrPScfromVPSPr.
However,1E4hasaloweraffinityforrPrPScfromGSS102comparedto3F4.
ItcouldbeduetothePrPP102Lmutationthatislocalizedwithinthe1E4epitope.
SinceVPSPr20andVPSPr17aredetectableby6D11thatisagainsthumanPrP93-109,theirN-terminaldomainsmaystartatleastfromresidue93.
VPSPr7isrecognizedby1E4thatisagainsthumanPrP97-105,suggestingthattheN-terminusofVPSPr7containsresidue97.
Pathogens2013,2460Figure1.
Cont.
PK(50g/ml)PNGaseF6D11(93-109)8G8(95-110)Anti-C(220-231)6H4(145-152)9A2(99-101)12B2(89-93)V14(185-196)--+-+-+-+-+-+-+-+-+-+GSS(102)GSS(102)sCJDMM1VPSPrGSS(117)-29-20-7-29-20-7-29-20-7-29-20-29-20-7-29-20-7-29-20DJIHGEFPathogens2013,24613.
PathognomonicLadder-LikeElectrophoreticProfileofProtease-ResistantPrPScwithaPeculiarImmunoreactivityBehaviorAlthoughundetectablewith3F4byconventionalWesternblotting,aladder-likeelectrophoreticprofileofPK-resistantPrPSc(rPrPSc)wasreadilydetectedwithanantibodycalled1E4,whichisunprecedentedinsporadichumanpriondiseases[4].
The1E4clonewasderivedfromhybridizationofSP2/0-Ag14myelomacellswithspleencellsfromaPrP-knockoutmouseimmunizedwiththepeptideQWNKPSKPKTNthatcorrespondstothebovinePrPaminoacidsequence108–119(http://www.
cellsciences.
com/content/p-detail.
asprowid=8107).
WhilethisantibodywasmostlyusedfordetectionofbovineandovinePrPSc,wedemonstratedthatthisantibodywithanepitopelocalizedbetweenhumanPrPresidues97and105(Yuanetal.
,2008)exhibitingthehighestaffinityforPrPScofPSPramongthenineanti-PrPantibodiesweexaminedincluding1E4(againstPrP97-105),3F4(PrP106-112),6D11(PrP93-109),8G8(PrP95-110),Anti-C(220-231),6H4(PrP145-152),9A2(PrP99-101),12B2(PrP89-93),andV14(PrP185-196)(Figure1).
Sincethe1E4-detectedladder-likeelectrophoreticprofileofrPrPScisveryuniqueandwasdetectedrepeatedlyinallelevencases,ithasbeenconsideredtobepathognomonicforPSPr.
ThediscoveryofthepathognomonicmolecularfeatureofPSPrhasgreatlyfacilitatedtheidentificationofthisuniquetypeofhumanpriondisease.
BearingthisfeatureofPSPrinmind,wereexaminedretroprospectivelysuspectedcasesreferredtotheNationalPrionDiseasePathologySurveillanceCenter(NPDPSC,Cleveland,OH,USA)between2002and2010includingtwocasesfromItaly[5].
Fornewly-referredcases,ithasbecomearoutineproceduretore-doWesternblotanalysiswiththe1E4antibodyinordertofindoutthepossiblecasesofPSPratNPDPSCiftheyarenegativeforrPrPScbyWesternblottingwith3F4butpositiveforH&Estainingandimmunohistochemistrywith3F4.
4.
Polymorphism-DependentPK-SensitiveandPK-ResistantPrPScIn2010,wefirstreportedthatPSPraffectsnotonlysubjectshomozygousforvalineatPrPresidue129butalsosubjectshomozygousformethionine(129MM)orheterozygousformethionine/valine(129MV)[5].
Ofthefifteencasesweexamined,oneofthetwoItaliancaseswaspreviouslyreportedbyGiacconeetal[3].
ComparedtotheinitiallyreportedPSPrinvalinehomozygotes,thelevelsofsPrPScweresignificantlydecreasedwhilethelevelsofrPrPScweresignificantlyincreasedin129MMor129MVcases.
Interestingly,itseemsthatthelevelsofrPrPScaredictatedbymethionineatresidue129.
Viceversa,thelevelsofsPrPScseemtobedictatedbyvalineatresidue129.
Althoughithasbeenwell-documentedthatPrPpolymorphismatresidue129isimplicatedinmediatingsusceptibilitytothedisease,phenotypesofdisease,andPrPSctypes[2],toourknowledge,ourstudyprovidedthefirstevidencethatthepolymorphismmayalsoparticipateinmedicatingtheamountsofsPrPScorrPrPSc[5].
Tomorepreciselyreflectthepolymorphism-dependentvariationinthelevelsofrPrPScorsPrPScinthisnewly-identifieddisease,werevisedtheoriginaldesignationas"variablyprotease-sensitiveprionopathy"(VPSPr)[5].
Pathogens2013,2462Figure2.
SchematicdiagramofelectrophoreticprofileofrPrPScfromVPSPrandsCJDprobedwith1E4.
WithoutPNGaseFtreatment,fiverPrPScfragmentsaredetectablewithWesternblottingincludingVPSPr26,VPSPr23,VPSPr20,VPSPr17,andVPSPr7fromVPSPrwhilethreerPrPScfragmentsaredetectedincludingdi-,mono-,andun-glycosylatedPrPfromclassicsCJD.
AfterPNGaseFtreatment,threecorePrPfragmentsremaininVPSPrincludingVPSPr20,VPSPr17,andVPSPr7whileonlyonecorePrPfragmentremainsinsCJD.
VPSPr26andVPSPr23aremonoglycosylatedformsofVPSPr20andVPSPr17,respectively.
5.
TheLadder-LikeElectrophoreticProfileof1E4-DetectedrPrPScConsistingofFivePrPFragmentsSomeoftherPrPScfragmentsbecamedetectableinVPSPr129MMandVPSPr129MVwiththe3F4antibody,especiallyintheformer.
Notably,eventhoughtheamountsofrPrPScinVPSPr129MMorVPSPr129MVweresignificantlyincreasedcomparedtothoseofrPrPScinVPSPr129VV,theprofileofrPrPScdetectedwith3F4isdifferentfromthatdetectedwith1E4.
ThemostsignificantdifferencesintherPrPScfragmentsdetectedwiththetwoantibodieswerethesmallestfragmentmigratingatapproximately7kDacalledVPSPr7thatwasdetectablewith1E4butnotwith3F4[5,6].
ExceptforVPSPr7,both3F4and1E4detectedtheotherfourrPrPScfragmentsmigratingat~26kDa,23kDa,20kDa,and17kDa,termedVPSPr26,VPSPr23,VPSPr20,andVPSPr17,respectively,whichisstrikinglydifferentfromrPrPScobservedinclassicsCJD(Figure2).
Basedongelmigration,VPSPr26correspondstomonoglycosylatedrPrPScoftheclassicsCJD,whereasVPSPr20correspondstounglycosylatedrPrPScofsCJD.
Interestingly,nodetectablediglycosylatedrPrPScwasobservedbyboth3F4and1E4inVPSPr,whichwasalsoobservedinthefirstcasereported[3].
Ontheotherhand,threeadditionalfragmentsVPSPr23,VPSPr17andVPSPr7werenotdetectableinsCJD.
APK-titrationofPrPScfromVPSPr129MMor129MVontheWesternblotsprobedwith1E4or3F4revealedthatVPSPr26andVPSPr20graduallyfadedawaywhileVPSPr23andVPSPr17becamedominantuponincreasesinthePKconcentrations,suggestingthatVPSPr23derivesfromVPSPr26whileVPSPr17fromVPSPr20.
Afterdeglycosylation,weconvincinglyshowedthatunglycosylatedVPSPr20decreasedwhileVPSPr17increased.
Asmentionedabove,VPSPr20maycorrespondtounglycosylatedrPrPScofsCJDanditmayencompassPrPsequencefromresidue90to231.
So,itismostlikelythattheswitchPathogens2013,2463fromVPSPr20toVPSPr17causedbyPK-digestionmaybeduetocleavageofaC-terminaldomainsincebothfragmentsweredetectedwithantibodiesagainsthumanPrP97-105(1E4)andPrP106-112(3F4).
Moreover,theantibodyAnti-CspecificforhumanPrP220-231detectedfourrPrPScafterdeglycosylationwithPNGaseF.
However,themigrationofthesefragmentsdetectedwithAnti-Cseemedtobedifferentfromthatof1E4-detectedfragmentsexceptforVPSPr20.
AllthesefindingssuggestthatconformationofPrPScinVPSPrisquitedifferentfromthatofPrPScinsCJDanditmayhavemanymorePK-cleavagesitesofPrPScinVPSPrthaninsCJD.
ThecleavagesmayoccurnotonlyattheN-terminaldomainbutalsoattheC-terminaldomain.
6.
Glycoform-SelectivePrionFormationinVPSPrandfCJDV180IIngeneral,thefourglycoformsofPrPCvariablyglycosylatedatthetwoN-linkedglycosylationsitesareusuallyallconvertedintotheirPrPSccounterpartsinallhumanpriondiseases[2].
However,thereareexceptions.
FamilialCJDlinkedtoeitherPrPT183A(fCJDT183A)orPrPV180I(fCJDV180I)mutationexhibitsanrPrPScthatlacksthediglycosylatedPrPspecies[12,13].
T183Amutationitselfisknowntocompletelyeliminatethefirstglycosylationsiteatresidue181[14],whichisbelievedtoaccountforthelackofdiglycosylatedrPrPSc.
However,themolecularmechanismunderlyingalterationinglycosylationbyV180Imutationisunknown.
Inadditiontothetwomutations,twocasesofatypicalsporadicCJDhavealsobeenreportedtolackdiglycosylatedrPrPSc[3,15],oneofwhichwassubsequentlyproventobeacaseofVPSPr[3,5].
TounderstandthemolecularmechanismunderlyingthelackofdiglycosylatedrPrPScandformationofladder-likeelectrophoreticprofileofrPrPScaswellastoinvestigatethepotentialassociationbetweensporadicVPSPrandfamilialCJDlackingdiglycosylatedPK-resistantPrPform,wecomparedtheirindividualPrPglycoformsusingantibodiesthatareabletodistinguishthetwoglycosylationsites[6,16,17].
Usingacombinationofinvivoandinvitroassays,wedemonstratedthattheabsenceofthediglycosylatedPrPScinbothVPSPrandfCJDV180Iisassociatedwiththeinabilityofthedi-andmono-glycosylatedPrPCwiththeintactfirstglycosylationsite(N181)toconvertintoPrPScinthebrain.
Surprisingly,fCJDV180IwasdetectedtohaveanrPrPScthatwasmarkedlysimilartothatobservedinVPSPr,withafive-stepladder-likeelectrophoreticprofile,apathognomonicmolecularfeatureofVPSPr[6].
Therefore,althoughVPSPrislinkedtowild-typePrPandfCJDV180IislinkedtomutantPrP,bothsporadicVPSPrandfCJDV180Imayshareauniqueglycoform-selectiveprionformationpathway.
Moreover,conformationofPrPScinthetwoconditionsalsomaybeverysimilar,asevidencedbythegenerationofavirtuallyidenticalelectrophoreticprofileofrPrPScuponPK-treatment.
Althoughthemolecularmechanismunderlyingglycoform-selectiveprionformationisunclearatpresent,thereareseveralcluesthatmaybeofsignificanceinunderstandingthismystery.
First,incontrasttofCJDT183A,bothVPSPrandfCJDV180IexhibitedanintactglycosylationpriortoPK-digestion.
Moreover,PrPV180Iinculturedcellshadatypicalglycoformprofile.
ItgenerateddetectabletypicalrPrPScwithdiglycosylatedPrPformuponPK-treatment,inadditiontomono-unglycosylatedformsalthoughtheyweredetectableonlywith1E4butnotwith3F4[6].
Therefore,PrPV180ImutationitselfdoesnoteliminateanyglycosylationsitesanditcanbeconvertedintorPrPScasdoeswild-typePrPC.
Second,adecreaseintheglycosylationpotentialvalueforthefirstglycosylationsitewaspredicatedbytheN-linkedglycosylationpredictionalgorithm[6],suggestingthatPrPV180ImayalterthePathogens2013,2464compositionofglycansatthefirstsite.
Third,diglycosylatedPrPormonoglycosylatedPrPcarryingmono181wasnotconvertedintorPrPSc,whichwasnotobservedinculturedcellsbutonlyobservedinthebraininwhichthereisanadditionalwild-typeallele.
Finally,comparedtosCJD,thebindingofricinuscommunisagglutininI(RCA-I)tomonoglycosylatedPrPdecreasedwhilethebindingtodiglycosylatedPrPincreasedinVPSPrandfCJDV180I[6],suggestingthatthetwodiseaseshaveachangedcompositionofglycans.
Therefore,itispossiblethatglycoform-selectiveprionformationobservedinbraininvolvesdominant-negativeinhibitioncausedbytheinteractionbetweenmisfoldedandnormalPrPmolecules.
Thechangedcompositionofglycansatthefirstsitebythemutationmayalterlocalconformationaroundresidue181thatisclosetotheβ-sheets2/α-helixes2loop,thecriticalregionimplicatedindominant-negativeinhibition[18].
Consistentwiththishypothesis,itseemsthattherearesignificantdifferencesintheeffectofmutationsoccurringateitherthefirstorthesecondglycosylationsiteontheconversionofPrPCintoPrPSc.
Whilemostofmutationsatthefirstsiteblockedtheconversion,noneoforafew,ifany,mutationsatthesecondsitewerefoundtoblockPrPCconversionincellandanimalmodels[19,20].
Morespecifically,interactionsbetweendifferentPrPCglycoformsmediatetheefficiencyofprionformation,whichinvolvesglycan-associatedsterichindrance[21].
ThesamegroupalsodemonstratedthatdominantnegativeinhibitionofprionformationrequiresnoproteinXoranyotheraccessorycofactor[22].
AlthoughnoPrPmutationshavebeenobservedinVPSPr,asimilaraberrantglycosylationatN181causedbyararestochasticeventhasbeenproposedtotriggertheprocessesasdescribedforfCJDV180I[6].
Anotherpossibilitytocauseglycoform-selectiveprionformationisthatoneormoreco-factorsmaybeoperatinginVPSPrandfCJDV180Iandtheco-factorsmaypreventconversionofdiglycosylatedPrPandmono181intoPrPSc.
Theremaybesomeimplicationsinthetwodiseasesthatotherco-factorsmaybeinvolvedinthepathogenesisofthediseases.
Forinstance,althoughlinkedtothePrPV180Imutation,nofamilyhistoryofneurodegenerativedisordershasbeenreportedinfCJDV180Icases[23].
Ontheotherhand,whilenomutationshavebeenidentifiedwithinthecodingsequence(theopenreadingframe)ofPrPgeneinVPSPrtodate,eightoutof26reportedVPSPrcasesshowedafamilialhistoryofdementia[5,24].
Indeed,severallinesofevidencehaveindicatedthatotherco-factorsmaybeinvolvedinthepathogenesisofpriondiseases,includingproteinXandnon-proteinaceouscofactors[25–27].
WhetherproteinXthatwasinitiallyproposedtodirectlyinteractwithPrPCisnecessaryforprionformationremainscontroversial[26,28].
However,genesorproteinsthatmayindirectlytriggertheconversionofPrPCintoPrPScmayexist.
ItispossiblethatamutationinaspecificgenethatparticipatesinregulatingPrPglycosylationmayalterglycosylationatthefirstglycosylationsiteandthencausesVPSPror/andfCJDV180I.
Ifthisisthecase,furtherinvestigationofthetwodiseasesmayprovideanopportunitytofindoutabouttheexistenceofsuchaco-factor.
7.
TransmissibilityofVPSPrandfCJDV180IIthasbeenwidelyacceptedthatanypriondiseasesmustbetransmissiblealthoughtherearesomepriondiseasesthathavenotbeentransmittedyet[29,30].
BeforeStanleyPrusinerdiscoveredprionsandcoinedprionin1982[31],thetermtransmissiblespongiformencephalopathy(TSE)hadbeenwidelyused.
Asindicatedbyitsstrikingname,aTSEmustpossessthesetwomajorcharacteristics:transmissibilityandspongiformdegenerationinthecentralnervoussystem(CNS).
ThediscoveryofPathogens2013,2465prionsasinfectiousproteinpathogens,whicharefreeofnuclearacidsandwhicharethecauseoftransmissiblespongiformencephalopathies,wasarevolutionarydevelopmentnotonlyforthefieldinparticularbutalsoforthelifescienceingeneral.
PrPSchasinfactbeenobservedinalmostallTSEidentifiedsofar.
IdentificationofPrPSchasbecomeessentialinthecurrentdiagnosticcriteriaforTSE.
Thedesignation,"priondiseases",haslargelyreplaced"transmissiblespongiformencephalopathy".
However,confusionresultswhenitisobservedthatsomepriondiseaseslackoneortwocharacteristicsofTSE.
Approximately10%ofsporadicCJDand32%offamilialpriondiseaseswerenon-transmissibleinnonhumanprimates[32].
Moreover,allGSS,exceptone-thirdofGSSP102Lcases,weredifficulttotransmittorodents[33].
Further,thespongiformdegenerationtypicalofTSEisnotalwayspresentinallGSSP102L,althoughdiffusedepositsofPrPScplusPrP-amyloidplaquesarepresentintheCNS[34].
IntransgenicmiceexpressingmurinePrPP101L(equivalenttohumanP102L)andchallengedwithGSSfreeofspongiformdegeneration,neithersymptomsnorspongiformdegenerationwasobserveddespitethepresenceofPrP-amyloid[35].
Obviously,conditionssuchasthese,whichdonotmanifesttransmissibilityorspongiformdegeneration(singlyorjointly),shouldnotbeconsideredastypesofTSE.
Theydo,however,constitutepriondiseases.
Basedonawealthofdatagatheredsofar,onemaywonderwhetherornotpriondiseasesshouldnowberedefined.
Underareconsidereddefinition,theyshouldincludeagroupofdisorderscharacterizedbytheaccumulationofabnormalPrPincludingprotease-sensitiveandprotease-resistantformsinthebrain,regardlessofthepresenceoftransmissibilityandspongiformdegeneration.
Mostimportantly,thespectrumofpriondiseasesmustnotberestrainedbythedefinitionofTSE.
Asapriondisease,VPSPrshouldlikewisemeetKoch'spostulatesaswell[36].
So,itwouldbeimportanttoinvestigatethetransmissibilityofVPSPrthatexhibitsthepeculiarPK-resistantbehaviorofPrP.
PreliminarydatarecentlyreportedbyNonnoetal.
indicatethattransmissibilityofVPSPr-129MM,-129MVand-129VVtobankvolesisrelatedtothebankvolemethionine/isoleucinepolymorphismatcodon109[37].
Furthermore,studieswithhumanizedmicesuggestthattransmissibilityofVPSPrismuchlowercomparedtoclassicsporadicCJD[38].
NoclinicalphenotypeswereobservedduringthenormallifespanoftransgenicmiceexpressinghumanPrP-129Vatapproximately10fold,followinginoculationwithbrainhomogenatesfromVPSPr-129VVcases.
Lessthan20%ofthemicewerefoundtohavescatteredPrPplaqueswithminimalornospongiformdegeneration,comparedtothetypicalneuropathologicalchangesfoundin100%miceinoculatedwiththeclassicsCJD[38].
Similarly,usingproteinmisfoldingcyclicamplification(PMCA)assay,wefoundthattheamplificationefficiencyofPrPScfromVPSPrismuchlowercomparedtoiatrogenicandsporadicCJD(Zouetal.
,unpublisheddata).
Todate,therearenoreportsavailabledemonstratingthatfCJDV180Iistransmissible[39].
Therefore,prionsinVPSPrandfCJDV180Iexhibitstrikingsimilaritiesnotonlyinphysicochemicalbutalsoinbiologicalproperties.
IncollaborationwithDrs.
Yong-SunKimandRobertPetersen,wearegeneratinghumanizedtransgenicmiceexpressinghumanPrPV180IcurrentlyandwillbetestingtransmissibilityofVPSPrandfCJDV180Iwiththisanimalmodel.
Pathogens2013,24668.
OriginofPrionsinVPSPrandfCJDV180IAsmentionedabove,prionsfromVPSPrandfCJDV18°Iareofuniquephysicochemicalandbiologicalproperties.
Remarkably,theyexhibitahighimmunoreactivitywiththe1E4antibodybutapoorreactivitywith3F4[5,6].
Wehavedemonstratedthatthetwoantibodieshaveadjacentepitopesandespeciallythe3F4epitope(PrP106-112)isnexttotheC-terminusofthe1E4epitope(PrP97-105)[9,40].
Becauseoftheuniquelocalizationofthetwoepitopes,itismostlikelythatallfive-steplikerPrPScfragmentsfromthetwodiseasescontainthe3F4epitope.
So,thepooraffinityof3F4forrPrPScfromVPSPrandfCJDV180Imayindicatethattheremightbesomelocalstructuresorbindingmoleculesthatblockthe3F4epitope.
Wehavenoticedthattheaffinityof3F4forrPrPScfromVPSPrwasincreasedinthepreparationsafterpurificationstepscomparedtounpurifiedtotalbrainhomogenates(Zouetal.
,unpublisheddata).
Thus,purificationproceduresmaysomehowremovethebindingmoleculesoralterthelocalstructures,whichmightmakethe3F4epitopeexposed.
Ontheotherhand,allthesefindingsmayalsosuggestthatPrPScfromVPSPrandfCJDV180IhaveanorigindifferentfromPrPScdetectedinotherhumanpriondiseases.
Usingthesame1E4antibody,wepreviouslyidentifiedaPK-resistantPrPspeciestermedinsolublePrPC(iPrPC)inuninfectedhumanbrainsandculturedcells[6,9,40,41,42].
ThesmallamountofPK-resistantPrPinuninfectedbrainsandcellsexhibitedthesamepeculiarimmunoreactivitybehavior:higheraffinityfor1E4butloweraffinityfor3F4.
Remarkably,theresemblancesofthreePK-resistantPrPcorefragmentsmigratingat~20kDa,17kDaand7kDaobservedinVPSPrweredetectedwith1E4inuninfectedhumanbrains[43].
ThesameimmunoreactivitybehaviorofiPrPCinuninfectedbrainsandrPrPScinVPSPrandfCJDV180IsuggeststhattheymayshareacommonmolecularmetabolicpathwayordistributionandthatVPSPrandfCJDV180ImayresultfromanincreaseintheamountofiPrPC[43].
9.
AssociationbetweenVPSPrandOtherPrionDiseasesInadditiontoV180IandT183Amutations,threeothernaturallyoccurringPrPmutationsincludingD178N,F198S,andE200KlinkedtofamilialpriondiseasehavereportedlybeenassociatedwithalteredratiosofthethreePrPglycoforms.
ButallthethreefamilialpriondiseasesdonothaverPrPScthatlacksdiglycosylatedform[39].
Moreover,the1E4-preferentiallydetectablerPrPSchasnotbeenidentifiedyet.
ThedepositioninthebrainofmultiplesmallPK-resistantPrPSc,especiallythe7-kDafragmentisthemolecularhallmarkofGSS[44].
Therefore,itisreasonableforustoanticipatesomepotentialassociationbetweenGSSandVPSPr.
Indeed,becauseofthelongdiseaseduration,multiplePK-resistantPrPfragments,andvariablePK-resistanceofPrPSc,VPSPrwasoncesuspectedtobethesporadicformofGSSassociatedwithPrPA117Vmutation(GSSA117)[5].
However,wealsoobserveddifferentratiosandimmunoreactivityofPrPScbetweenVPSPrandGSSA117Vinthesamestudy.
ItisknownthatGSSisfrequentlyassociatedwithapredominantlycerebellardysfunctionandismainlycharacterizedbythedepositionofmulticentricplaquesinthecerebellum[39].
Incontrast,VPSPrlackstypicalmulticentricplaqueswhileitexhibitsdot-likestainingorsmallplaque-likeformationsinthecerebellum[5].
WhetherVPSPristhesporadicformoffCJDV180IorGSSA117Vneedstobefurtherdetermined.
ItisconceivablethatcellsandanimalsexpressinghumanPrPV180IorPrPA117Vwillprovidevalidmodelsforaddressingtheoutstandingquestions.
Pathogens2013,2467ThefactthatasmallPK-resistantrPrPScmigratingat~6–7kDathathasbeenbelievedtobeamolecularhallmarkofvariousGSSisalsodetectableinbothVPSPrandNor98[2,5,7,34,35,44]mayimplyapossibleassociationamongthesediseases.
Togaininsightsintotheirapparentsimilarityanddifferenceandtoinvestigatepossiblerelationshipsamongthem,wefurthercomparedthesmallfragmentfromVPSPr,Nor98,variousGSSlinkedtoP102L,A117V,orF198SPrPmutation[8,45].
ItwasdemonstratedthatVPSPrandNor98sharebothsimilaranddistinctivefeatures.
Forinstance,interestingly,theyallhaveacorerPrPScfragmentencompassingPrP97-142whilethefragmentcanhavevariedN-andC-terminalcleavagesites(Table1)[45].
Table1.
Antibodymappingofthe6–7kDasmallrPrPSc[45].
MAbsEpitopesHumanSheepVPSPrA117F198S102sCJDNor98SAF32Octarepeat12B289–939A299–1016D1193–1098G895–110F89139–142L42145–15012F10143–152Repeatregionaminoacids:59–65;67–73;75–81;83–89–:Nosignal;+:strongsignal;and+/–:weeksignal.
10.
ConclusionsPrionsfoundinsporadicVPSPrareclearlydifferentfromthoseofallotherclassicsporadichumanpriondiseases.
BothVPSPrandfCJDV180IsharessimilarphysicochemicalpropertiesofPrPScandaglycoform-selectiveprionformationpathway.
Thefindingoftheeffectofpolymorphismatresidue129onthelevelsofrPrPScandsPrPScfurtheremphasizestheroleofthepolymorphisminthepathogenesisofhumanpriondiseases.
Thetwodiseasesspecificallyalterglycosylationatthefirstglycosylationsiteatresidue181ofPrP,whichmayinvolveanon-PrPproteinthatparticipatesinregulatingPrPglycosylation.
Becauseofsimilarimmunoreactivityandenzymaticfragmentation,PrPScinVPSPrandfCJDV180ImayhaveanoriginsimilartoiPrPC.
ThepossiblecorrelationbetweenhumanVPSPrandsheepNor98isinterestingbutremainstobefurtherinvestigated.
ThelowtransmissibilityofVPSPrandfCJDV180Imayresultfromalteredposttranslationalmodificationsincludingnotonlyglycosylationbutalsotheglycophosphatidylinositol(GPI)anchor.
WhetherthereareanychangesinGPIanchorremainsunknown.
OurcurrentproteinsequencingstudyandglycananalysisofpurifiedrPrPScwillprovideinsightsintotheseissues.
FuturestudieswiththetwodiseasesandwithcellandanimalmodelsexpressingPrPV180Imutationwillhelpusunderstandthepossibleco-factorsandmolecularmechanismsunderlyingtheformationoftheuniqueprionsidentifiedinVPSPrandfCJDV180I.
Pathogens2013,2468AcknowledgementsTheauthorswanttothankHubertLaudeandMohammedMoudjonforkindlyprovidingtheV14antibody.
ThisstudywassupportedbygrantsfromtheNationalInstitutesofHealthR01NS062787,theCJDFoundation,andtheUniversityCenteronAgingandHealthwiththesupportoftheMcGregorFoundationandthePresident'sDiscretionaryFund(CaseWesternReserveUniversity)toWQZaswellasgrantsfromNIHP01AG-14359,CharlesS.
BrittonFund,CDCUR8/CCU515004toPG.
ConflictofInterestTheauthorsdeclarenoconflictofinterest.
References1.
Prusiner,S.
B.
Prions.
Proc.
Natl.
Acad.
Sci.
USA1998,95,13363–13383.
2.
Gambetti,P.
;Kong,Q.
;Zou,W.
Q.
;Parchi,P.
;Chen,S.
G.
SporadicandinheritedCJD:Classificationandcharacterisation.
Br.
Med.
Bull.
2003,66,213–239.
3.
Giaccone,G.
;DiFede,G.
;Mangieri,M.
;Limido,L.
;Capobianco,R.
;Suardi,S.
;Grisoli,M.
;Binelli,S.
;Fociani,P.
;Bugiani,O.
;Tagliavini,F.
AnovelphenotypeofsporadicCreutzfeldt-Jakobdisease.
J.
Neurol.
Neurosurg.
Psychiatry2007,78,1379–1382.
4.
Gambetti,P.
;Dong,Z.
;Yuan,J.
;Xiao,X.
;Zheng,M.
;Alshekhlee,A.
;Castellani,R.
;Cohen,M.
;Barria,M.
A.
;Gonzalez-Romero,D.
;Belay,E.
D.
;Schonberger,L.
B.
;Marder,K.
;Harris,C.
;Burke,J.
R.
;Montine,T.
;Wisniewski,T.
;Dickson,D.
W.
;Soto,C.
;Hulette,C.
M.
;Mastrianni,J.
A.
;Kong,Q.
;Zou,W.
Q.
Anovelhumandiseasewithabnormalprionproteinsensitivetoprotease.
Ann.
Neurol.
2008,63,697–708.
5.
Zou,W.
Q.
;Puoti,G.
;Xiao,X.
;Yuan,J.
;Qing,L.
;Cali,I.
,Shimoji,M.
;Langeveld,J.
P.
;Castellani,R.
;Notari,S.
;Crain,B.
;Schmidt,R.
E.
;Geschwind,M.
;Dearmond,S.
J.
;Cairns,N.
J.
;Dickson,D.
;Honig,L.
;Torres,J.
M.
;Mastrianni,J.
;Capellari,S.
;Giaccone,G;Belay,E.
D.
;Schonberger,L.
B.
;Cohen,M.
;Perry,G.
;Kong,Q.
;Parchi,P.
;Tagliavini,F.
;Gambetti,P.
Variablyprotease-sensitiveprionopathy:Anewsporadicdiseaseoftheprionprotein.
Ann.
Neurol.
2010,68,162–172.
6.
Xiao,X.
;Yuan,J.
;Hak,S.
;Cali,I.
;Zhan,Y.
;Moudjou,M.
;Li,B.
;Laplanche,J.
L.
;Laude,H.
;Langeveld,J.
;Gambetti,P.
;Kitamoto.
T.
;Kong,Q.
;Brandel,J.
P.
;Cobb,B.
A.
;Petersen,R.
B.
;Zou,W.
Q.
Glycoform-selectiveprionformationinsporadicandfamilialformsofpriondisease.
PLoSOne2013,8,e58786.
7.
Benestad,S.
L.
;Sarradin,P.
;Thu,B.
;Schnheit,J.
;Tranulis,M.
A.
;Bratberg,B.
CasesofscrapiewithunusualfeaturesinNorwayanddesignationofanewtype,Nor98.
VetRec.
2003,153,202–208.
8.
Pirisinu,L.
;Nonno,R.
;Gambetti,P.
;Agrimi,U.
;Zou,W.
Q.
ComparativestudyofsheepNor98withhumanvariablyprotease-sensitiveprionopathyandGerstmann-Strussler-Scheinkerdisease.
Prion5.
2011,5,76.
Pathogens2013,24699.
Zou,W.
Q.
;Langeveld,J.
;Xiao,X.
;Chen,S.
;McGeer,P.
L.
;Yuan,J.
;Payne,M.
C.
;Kang,H.
E.
;McGeehan,J.
;Sy,M.
S.
;Greenspan,N.
S.
;Kaplan,D.
;Wang,G.
X.
;Parchi,P.
;Hoover,E.
;Kneale,G.
;Telling,G.
;Surewicz,W.
K.
;Kong,Q.
;Guo,J.
P.
PrPconformationaltransitionsalterspeciespreferenceofaPrP-specificantibody.
J.
Biol.
Chem.
2010,285,13874–13884.
10.
Zou,W.
Q.
;Zheng,J.
;Gray,D.
M.
;Gambetti,P.
;Chen,S.
G.
AntibodytoDNAdetectsscrapiebutnotnormalprionprotein.
Proc.
Natl.
Acad.
Sci.
USA2004,101,1380–1385.
11.
Wadsworth,J.
D.
;Joiner,S.
;Hill,A.
F.
;Campbell,T.
A.
;Desbruslais,M.
;Luthert,P.
J.
;Collinge,J.
TissuedistributionofproteaseresistantprionproteininvariantCreutzfeldt-Jakobdiseaseusingahighlysensitiveimmunoblottingassay.
Lancet2001,358,171–180.
12.
Grasbon-Frodl,E.
;Lorenz,H.
;Mann,U.
;Nitsch,R.
M.
;Windl,O.
;Kretzschmar,H.
A.
LossofglycosylationassociatedwiththeT183Amutationinhumanpriondisease.
ActaNeuropathol.
2004,108,476–484.
13.
Chasseigneaux,S.
;Hak,S.
;Laffont-Proust,I.
;DeMarco,O.
;Lenne,M.
;Brandel,J.
P.
;Hauw,J.
J.
;Laplanche,J.
L.
;Peoc'h,K.
V180ImutationoftheprionproteingeneassociatedwithatypicalPrPScglycosylation.
Neurosci.
Lett.
2006,408,165–169.
14.
Capellari,S.
;Zaidi,S.
I.
;Long,A.
C.
;Kwon,E.
E.
;Petersen,R.
B.
TheThr183Alamutation,notthelossofthefirstglycosylationsite,altersthephysicalpropertiesoftheprionprotein.
J.
AlzheimersDis.
2000,2,27–35.
15.
Zanusso,G.
;Polo,A.
;Farinazzo,A.
;Nonno,R.
;Cardone,F.
;DiBari,M.
;Ferrari,S.
;Principe,S.
;Gelati,M.
;Fasoli,E.
;Fiorini,M.
;Prelli,F.
;Frangione,B.
;Tridente,G.
;Bentivoglio,M.
;Giorgi,A.
;Schininà,M.
E.
;Maras,B.
;Agrimi,U.
;Rizzuto,N.
;Pocchiari,M.
;Monaco,S.
NovelprionproteinconformationandglycotypeinCreutzfeldt-Jakobdisease.
Arch.
Neurol.
2007,64,595–599.
16.
Moudjou,M.
;Treguer,E.
;Rezaei,H.
;Sabuncu,E.
;Neuendorf,E.
;Groschup,M.
H.
;Grosclaude,J.
;Laude,H.
Glycan-controlledepitopesofprionproteinincludeamajordeterminantofsusceptibilitytosheepscrapie.
J.
Virol.
2004,78,9270–9276.
17.
Féraudet,C.
;Morel,N.
;Simon,S.
;Volland,H.
;Frobert,Y.
;Créminon,C.
;Vilette,D.
;Lehmann,S.
;Grassi,J.
Screeningof145anti-PrPmonoclonalantibodiesfortheircapacitytoinhibitPrPScreplicationininfectedcells.
J.
Biol.
Chem.
2005,280,11247–11258.
18.
Cong,X.
;Bongarzone,S.
;Giachin,G.
;Rossetti,G.
;Carloni,P.
;Legname,G.
Dominant-negativeeffectsinpriondiseases:insightsfrommoleculardynamicssimulationsonmouseprionproteinchimeras.
J.
Biomol.
Struct.
Dyn.
2012,Aug30.
[Epubaheadofprint]19.
Salamat,M.
K.
;Dron,M.
;Chapuis,J.
;Langevin,C.
;Laude,H.
PrionpropagationincellsexpressingPrPglycosylationmutants.
J.
Virol.
2011,85,3077–3085.
20.
Tuzi,N.
L.
;Cancellotti,E.
;Baybutt,H.
;Blackford,L.
;Bradford,B.
;Plinston,C.
;Coghill,A.
;Hart,P.
;Piccardo,P.
;Barron,R.
M.
;Manson,J.
C.
HostPrPglycosylation:Amajorfactordeterminingtheoutcomeofprioninfection.
PLoSBiol.
2008,6,e100.
21.
Nishina,K.
A.
;Deleault,N.
R.
;Mahal,S.
P.
;Baskakov,I.
;Luhrs,T.
;Riek,R.
;Supattapone,S.
ThestoichiometryofhostPrPCglycoformsmodulatestheefficiencyofPrPScformationinvitro.
Biochemistry2006,45,14129–14139.
Pathogens2013,247022.
Geoghegan,J.
C.
;Miller,M.
B.
;Kwak,A.
H.
;Harris,B.
T.
;Supattapone,S.
Trans-dominantinhibitionofprionpropagationinvitroisnotmediatedbyanaccessorycofactor.
PLoSPathog.
2009,5,e1000535.
23.
Mutsukura,K.
;Satoh,K.
;Shirabe,S.
;Tomita,I.
;Fukutome,T.
;Morikawa,M.
;Iseki,M.
;Sasaki,K.
;Shiaga,Y.
;Kitamoto,T.
;Eguchi,K.
FamilialCreutzfeldt-JakobdiseasewithaV180Imutation:Comparativeanalysiswithpathologicalfindingsanddiffusion-weightedimages.
DementGeriatr.
Cogn.
Disord.
2009,28,550–557.
24.
Jansen,C.
;Head,M.
W.
;vanGool,W.
A.
;Baas,F.
;Yull,H.
;Ironside,J.
W.
;Rozemuller,A.
J.
Thefirstcaseofprotease-sensitiveprionopathy(PSPr)inTheNetherlands:ApatientwithanunusualGSS-likeclinicalphenotype.
J.
Neurol.
Neurosurg.
Psychiatry2010,81,1052–1055.
25.
Telling,G.
C.
;Scott,M.
;Mastrianni,J.
;Gabizon,R.
;Torchia,M.
;Cohen,F.
E.
;DeArmond,S.
J.
;Prusiner,S.
B.
PrionpropagationinmiceexpressinghumanandchimericPrPtransgenesimplicatestheinteractionofcellularPrPwithanotherprotein.
Cell1995,83,79–90.
26.
Supattapone,S.
;Miller,M.
B.
CofactorInvolvementinPrionPropagation.
InPrionsandDiseases:PhysiologyandPathophysiology;Zou,W.
Q.
,Gambetti,P.
,Eds.
;SpringerScience+BusinessMedia:NewYork,NY,USA,2013;Volume1,pp.
93–105.
27.
Ma,J.
PrionProteinConversionandLipids.
InPrionsandDiseases:PhysiologyandPathophysiology;Zou,W.
Q.
,Gambetti,P.
,Eds.
;SpringerScience+BusinessMedia:NewYork,NY,USA,2013;Volume1,pp.
107–119.
28.
Colby,D.
W.
;Prusiner,S.
B.
Prions.
ColdSpringHarb.
Perspect.
Biol.
2011,3,a006833.
29.
Zou,W.
Q.
Transmissiblespongiformencephalopathyandbeyond(E-letter).
Science.
Availableonline:http://www.
sciencemag.
org/content/308/5727/1420.
long/reply#sci_el_10316(accessedon20September2007).
30.
Zou,W.
Q.
;Gambetti,P.
Modelingofhumanprionsandpriondiseasesinvitroandinvivo.
DrugDisc.
Today:Dis.
Mod.
2004,1,157.
31.
Prusiner,S.
B.
Novelproteinaceousinfectiousparticlescausescrapie.
Science1982,216,136–144.
32.
Brown,P.
;Gibbs,C.
J.
,Jr.
;Rodgers-Johnson,P.
;Asher,D.
M.
;Sulima,M.
P.
;Bacote,A.
;Goldfarb,L.
G.
;Gajdusek,D.
C.
Humanspongiformencephalopathy:TheNationalInstitutesofHealthseriesof300casesofexperimentallytransmitteddisease.
Ann.
Neurol.
1994,35,513–529.
33.
Tateishi,J.
;Kitamoto,T.
;Hoque,M.
Z.
;Furukawa,H.
ExperimentaltransmissionofCreutzfeldt-Jakobdiseaseandrelateddiseasestorodents.
Neurology1996,46,532–537.
34.
Parchi,P.
;Chen,S.
G.
;Brown,P.
;Zou,W.
;Capellari,S.
;Budka,H.
;Hainfellner,J.
;Reyes,P.
F.
;Golden,G.
T.
;Hauw,J.
J.
;Gajdusek,D.
C.
;Gambetti,P.
DifferentpatternsoftruncatedprionproteinfragmentscorrelatewithdistinctphenotypesinP102LGerstmann-Strussler-Scheinkerdisease.
Proc.
Natl.
Acad.
Sci.
USA1998,95,8322–8327.
35.
Piccardo,P.
;Manson,J.
C.
;King,D.
;Ghetti,B.
;Barron,R.
M.
Accumulationofprionproteininthebrainthatisnotassociatedwithtransmissibledisease.
Proc.
Natl.
Acad.
Sci.
USA2007,104,4712–4717.
36.
Zou,W.
Q.
;Gambetti,P.
Frommicrobestoprions:Thefinalproofoftheprionhypothesis.
Cell2005,121,155–157.
Pathogens2013,247137.
Nonno,R.
;DiBari,M.
;Pirisinu,L.
;D'Agostino,C.
;Marcon,S.
;Riccardi,G.
;Vaccari,G.
;Parchi,P.
;Zou,W.
Q.
;Gambetti,P.
;Agrimi,U.
Variablyprotease-sensitiveprionopathyistransmissibleinbankvoles.
Prion2012,6,6.
38.
Gambetti,P.
;Xiao,X.
;Yuan,J.
;Cali,I.
;Kong,Q.
;Zou,W.
Q.
Variablyprotease-sensitiveprionopathy:TransmissibilityandPMCAstudies.
Prion2011,5,14.
39.
Kong,Q.
;Surewicz,W.
K.
;Petersen,R.
B.
;Zou,W.
Q.
;Chen,S.
G.
;Parchi,P.
;Capellari,S.
;Goldfarb,L.
;Montagna,P.
;Lugaresi,E.
;Piccardo,P.
;Ghetti,B.
;Gambetti,P.
InheritedPrionDiseases.
InPrionBiologyandDiseases;Prusiner,S.
B.
,Ed.
;ColdSpringHarborLaboratoryPress:NewYork,NY,USA,2004;pp.
673–775.
40.
Yuan,J.
;Dong,Z.
;Guo,J.
P.
;McGeehan,J.
;Xiao,X.
;Wang,J.
;Cali,I.
;McGeer,P.
L.
;Cashman,N.
R.
;Bessen,R.
;Surewicz,W.
K.
;Kneale,G.
;Petersen,R.
B.
;Gambetti,P.
;Zou,W.
Q.
Accessibilityofacriticalprionproteinregioninvolvedinstrainrecognitionanditsimplicationsfortheearlydetectionofprions.
CellMol.
LifeSci.
2008,65,631–643.
41.
Yuan,J.
;Xiao,X.
;McGeehan,J.
;Dong,Z.
;Cali,I.
;Fujioka,H.
;Kong,Q.
;Kneale,G.
;Gambetti,P.
;Zou,W.
Q.
Insolubleaggregatesandprotease-resistantconformersofprionproteininuninfectedhumanbrains.
J.
Biol.
Chem.
2006,281,34848–34858.
42.
Zou,W.
Q.
InsolubleCellularPrionProtein.
InPrionsandDiseases:PhysiologyandPathophysiology;Zou,W.
Q.
,Gambetti,P.
,Eds.
;SpringerScience+BusinessMedia:NewYork,NY,USA,2013;Volume1,pp.
67–82.
43.
Zou,W.
Q.
;Zhou,X.
;Yuan,J.
;Xiao,X.
InsolublecellularprionproteinanditsassociationwithprionandAlzheimerdiseases.
Prion2011,5,172–178.
44.
Tagliavini,F.
;Prelli,F.
;Ghiso,J.
;Bugiani,O.
;Serban,D.
;Prusiner,S.
B.
;Farlow,M.
R.
;Ghetti,B.
;Frangione,B.
AmyloidproteinofGerstmann-Strussler-Scheinkerdisease(Indianakindred)isan11kdfragmentofprionproteinwithanN-terminalglycineatcodon58.
EMBOJ.
1991,10,513–519.
45.
Pirisinu,L.
;Nonno,R.
;Esposito,E.
;Benestad,S.
L.
;Gambetti,P.
;Agrimi,U.
;Zou,W.
Q.
SmallruminantNor98prionssharebiochemicalfeatureswithhumanGerstmann-Strussler-Scheinkerdiseaseandvariablyprotease-sensitiveprionopathy.
PLoSONE2013,8,e66405.
2013bytheauthors;licenseeMDPI,Basel,Switzerland.
ThisarticleisanopenaccessarticledistributedunderthetermsandconditionsoftheCreativeCommonsAttributionlicense(http://creativecommons.
org/licenses/by/3.
0/).