Identification of a protein involved in the specific interaction between spermatogenic and Sertoli cells of the rat
著者 前田 智司
著者別名 Maeda, T.
journal or
publication title
博士学位論文要旨 論文内容の要旨および論文審査 結果の要旨/金沢大学大学院自然科学研究科
volume 平成11年6月
page range 1‑4
year 1999‑06‑01
URL http://hdl.handle.net/2297/16169
前田智司 氏名
生年月日 本籍 学位の種類 学位記番号 学位授与の日付 学位授与の要件
東京都 博士(薬学)
博甲第260号 平成10年3月31日
課程博士(学位規則第4条第1項)
Identificationofaproteininvolvedinthespecific interactionbetweenspermatogenicandSertolicellsofthe rat(精子形成細胞とセルトリ細胞の特異的な接着を規定するタン パク質の同定)
(主査)中西義信
(副査)大場義樹,正宗行人,松永司,山口正晃 学位授与の題目
論文審査委員
学位論文要旨
ThemammalianspermatogenicpathwayisacomplexprocessthatinvO1vestheproliferationof
thetesticularstemcellscalledspermatogonia,themeioticdivisionofspermatogoniagivingriseto
haploidspermatids$andthemorphogenicdifferentiationofspermatidsintospermatozoaThiswhole processcontinuesformorethanfourweeksintheseminiferoustubuIesofthemammaliantestis・ThroughoutthespermatogenlcpathwayjspermatogeniccellskeepaclosecontactwithSertolicells1
testicularsomaticcells・SertoIiceⅡshavethusbeenpresumedtopIayanimportantroleinthe spermatogenicdifferentiation,transferringmanymateriaIsandsignalstospermatogeniccelIsAlthoughanumberofproteinswithcelladhesionactivityexistinbothspermatogenicandSertolicelIs,
itisnotcertainwhetheranyofthemaretrulyinvolvedinthespecificassociationbetweenthetwocell typeslnthisstudy,lattemptedtoidentifyaproteinresponsibleforthisassociationusingan expressioncloningmethod
1)EstablishmentofceIIadhesionassay
Whenrattesticularcellswerep「imaryco-cultured,spermatogeniccells
weremaintainedinassociationwithSertolicellsthatgrewasamonolayer、lnordertoidentifythemoIecule(s)responsiblefo「thespecificinteractionbetween thetwocelltypes1IestabIishedaquantitativecelladhesionassayusing spermatogenicandSertoliceI1sisolatedfromaprimaryculture・
Ineachcelladhesionassay,thenumberofspermatogeniccellsboundto
Sertolicellswasdeterminedandshownrelativetotheinputcells,takenaslOOiie.,thecelladheslonindex・UndertheestabIishedconditions,spermatogenic celIspreparedfroma3-dayco-cultureroutinelygaveindexesofl3~30.
1
2)MolecuIarcIonIngofspermatogenlccelIproteinresponsibIefor spermatogenic‐SertoIiInteractIon
ldecidedtoidentifyacelladhesIonmolecuIe(s)inspermato9eniccells
employin9anexpressioncloningmethodlfirstsoughtaculturecelllinesuitable
forthehostforcloning、Therequirementsforhostcellswereasfollowsithecellsgrowinsuspension,donotbindtoSertolicells,andexpresstheSV401argeT‐
antigenthatallowsapIasmidcontainingtheSV40replicationorigintorepIicate
extrachromosomaIIy・AhumanT-cell-derivedcellIineJurkatTagmetallthe requirements,showinganadhesionindexofaboutl/5ofthatwithcontrol
spermatogeniccellsAcDNAlibrarywithacomplexityof2xlO6waspreparedfromthemRNAof
spermatogeniccellsusingamammalianexpressionvectorpcDNAl/Ampthat containstheSV40replicationorigin・ThelibrarywasintroducedintoJurkatTag cellsbyelectroporation,andthecellsthatacquiredtheabiIitytobindtoSertoli
cellswereselectedinthecelladhesionassay.Aftermulti-roundofsuch functionalscreenlng1fourcDNAcloneswereeventualIyisolatedTwoofthefourcDNAclones(#78and#97)werebroughttothefinal
examinationforthebindingtoSertolicells、Todoso,theirinsertswereisolated andrecIonedwiththepHook-2vector,whichexpressedasingle-chainantibody againstthephOxhaptenandallowedseIectionofthetransfectantsthatexpress anintroducedDNAusinglatexbeadscontainingthehapten・TheinsertsofW8 and#g7cIoneswereligatedwiththevectorandtheresultingDNAwere introducedintoJurkatTagcells,andceⅡsexpressingthecDNAwerepurified、
ThesecellswereanalyzedforthebindingtoSertolicells,togetherwithJurkat Tagcellsexpressingtheemptyvector(negativecontrol)andspermatogeniccells (positivecontrol).ThecIone#g7showedasignificantbindingactivity coT1parabletothatofcontrolspermatogeniccelIswhilethecellsexpressing
clcne#78didnotbindtoSertolicells、Theseresultsindicatedthatclone#g7wastheonewhichcodedforthespermatogenicprotemresponsibleforthe birdingofspermatogenicceIlstoSertoIicells、Thereasonforafailureof detectingtheactivitywiththeclone#78isnotclearatpresent,butitmaybe possibIethattheproteinencodedbytheclonewasnotproperlyexpressedunder thisexperimentalcondition,lwentfurthertodeterminethepropertyofthe#g7
clone-encodedprotein.
3)CharacterizatIonofceIIadhesionprotein
The#97cDNAclonecoveredaDNAregionofaboutl3kbpinlength
inCludinganopenreadingframefor243aminoacidresiduesApredicted
molecularmassoftheencodedproteinwas27kDa-2-