Functional Interaction between Mouse Spermatogenic LVA and Thapsigargin-Modulated Calcium Channels

Developmental Biology

Christophe Arnoult¹  Séverine Stamboulian¹  Michel Villaz¹  Michel De Waard¹ 

[1] CEA/Grenoble, Laboratoire INSERM E9931 “Canaux Ioniques et Signalisation” 17 rue des Martyrs, F-38054, Grenoble, France

关键词: mouse;    spermatogenic cells;    calcium channel;    T-type calcium channel;    TRP calcium channel;    capacitative calcium entry;    inositol 1;    4;    5 trisphosphate receptor;    acrosome reaction;   

DOI  :  10.1006/dbio.2002.0844

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Theacrosomereactioninmouseistriggeredbyalong-lastingcalciumsignalingproducedbyachainofopeningsofseveralcalciumchannels,alow-voltage-activated(LVA)calciumchannel,aninositoltrisphosphatereceptor(IP3R),andthestore-operatedcalciumchannelTRP2.Sincematurespermcellsarerefractorytopatchclampexperiments,westudythefunctionalinteractionsamongthosespermcalciumchannelsinspermatogeniccells.Wehavestudiedtheroleofcytosoliccalciuminvoltage-dependentfacilitationoflowvoltage-activatedcalciumchannels.Calciumconcentrationwasmodifiedthroughtheinclusionofthecalciumbuffers,EGTAandBAPTA,intherecordingpipettesolution,andbyadditionofcalciummodulatorslikethapsigarginandthecalciumionophoreA23187.Wedemonstratethatloweringcalciumconcentrationbelowrestinglevelallowstoevidenceavoltage-dependentfacilitation.WealsoshowthatLVAcalciumchannelspresentstrongvoltage-dependentinhibitionbythapsigargin.ThiseffectisindependentofcytosoliccalciumelevationsecondarytocalciumstoredepletionandtotheactivationofTRPchannels.Ourdataevidenceaninterestingfunctionalrelationship,inthiscelltype,betweenLVAchannelsandproteinswhoseactivityisrelatedtocalciumfillingstateoftheendoplasmicreticulum(presumablyTRPchannelsandinositoltriphosphatereceptor).Theserelationshipsmaycontributetotheregulationofcalciumsignalingduringacrosomereactionofmaturespermcell.

【 授权许可】

Unknown