Mechanisms of calcium independent but voltage dependent secretion(CiVDS) in somata of mammalian primary sensory neurons
作者单位：State Key Laboratory of Biomembrane-Center for Life Sciences-McGovern Brain Research Institute Institute of Molecular Medicine Peking University
会议名称：《中国神经科学学会第十二届全国学术会议》
会议日期：2017年
学科分类：0710[理学-生物学] 07[理学] 071006[理学-神经生物学]
关 键 词：Ca2+-independent but voltage-dependent secretion(CiVDS) Cav2.2 SNARE synprint DRG
摘 要：The somata of primary sensory neurons, including dorsal root ganglion(DRG) neurons, release neurotransmitters and neuropeptides. Following physiological action potentials, in addition to Ca-dependent secretion, we have discovered and studied Ca-independent but voltage-dependent secretion(CiVDS) in somata of freshly isolated DRG neurons(Zhang et al, 2002, 2004;Zheng et al, 2009, Liu et al, 2011). Major open question of CiVDS is the molecular mechanism, including 3 components: fusion pore machinery(FP), voltage sensor(VS) and the FP-VS linker(LK). Here we report, by using exocytosis assays of patch-clamp recording of membrane capacitance, and single vesicle imaging(EM and TIRF),(1) FP is jointly contributed by 2 components of SNARE complex, SNAP25 and syntaxin;(2) VS is contributed by voltage-gated Ca channels(VGCCs), Cav2.2(N-type VGCC);(3) LK is the synprint, Cav2.2 intracellular loop718-963 aa(Catterall, 1999);(4) following automatic knockdown of CiVDS by 3 d-culture of DRG neurons, CiVDS is rescued by overexpressing any component of FP(SNAPE25 or syntaxin) or VS(Cav2.2);(5) CiVDS is inhibited by blockers against FP(SNAP25 or sytaxin), VS(Cav2.2) and LK(synprint-truncated);(6) finally, CiVDS is blocked by Cav2.2-RNAi-KD in DRG pre-transfected in vivo.