The role of alpha2delta in neuronal VGCC modulation

描述（由申请人提供）： 这项工作的目标是更好地理解辅助α 2 δ亚基如何调节影响神经元迁移的神经元电压门控钙通道（VGCC）（Komuro，et.等人，1998）、突触发生（Bahls，et.例如，1998）和神经传递（Dunlap，1995）。神经元VGCC由α 1孔亚基和辅助亚基α 2 δ、β和可能的γ组成，其差异调节通道特性（卡特拉尔，2000）。对异源表达系统的研究表明，α 2 δ亚基与α 1结合，并通过改变VGCC的膜运输和生物物理性质来调节通道功能（Klugbauer，et.等人，2003）。然而，α 2 δ在调节成孔α 1亚基中的体内功能尚不清楚。已经分离出几个果蝇α 2 δ亚基中具有遗传损伤的straightjacket（stj）突变体。stj突变体的初步电生理和EM研究提示囊泡融合的缺陷。我建议研究果蝇α 2 δ的体内功能，重点是它在调节神经元VGCC和神经传递中的作用。首先，我将产生α 2 δ的无效等位基因，以帮助孤立突变的遗传特征。然后，我将调查VGCC贩运stj突变体使用荧光标记的α 1孔亚基。此外，我将使用钙成像来确定α 2 δ是否调节通道功能。最后，我将探讨α 2 δ和β之间的相互作用是否是正确的VGCC功能所必需的。

DESCRIPTION (provided by applicant): The goal of this work is to better understand how auxiliary alpha2delta subunits modulate neuronal voltage-gated calcium channels (VGCCs) which affect neuronal migration (Komuro, et. al,1998), synaptogenesis (Bahls, et. al., 1998), and neurotransmission (Dunlap, 1995). Neuronal VGCCs consist of an alpha1 pore subunit and auxiliary subunits, alpha2delta, beta, and possibly gamma, which differentially regulate channel properties (Catterall, 2000). Studies in heterologous expression systems suggest that alpha2delta subunits associate with alpha1 and modulate channel function by altering the membrane trafficking and biophysical properties of VGCCs (Klugbauer, et. al, 2003). However, the in vivo function of alpha2delta in regulating pore-forming alpha1 subunits is less clear. Several straightjacket (stj) mutants with genetic lesions in the Drosophila alpha2delta subunit have been isolated. Initial electrophysiological and EM studies of stj mutants hint at defects in vesicle fusion. I propose to study the in vivo function of Drosophila alpha2delta, focusing on its role in regulating neuronal VGCCs and neurotransmission. Initially, I will generate null alleles of alpha2delta to aid in the genetic characterization of isolated mutations. I will then investigate VGCC trafficking in stj mutants using a fluorescent-tagged alpha1 pore subunit. In addition, I will determine whether alpha2delta modulates channel function using calcium imaging. Finally, I will explore whether interactions between alpha2delta and beta are necessary for proper VGCC function.