Elucidation of the physiological role of BARP, a new blocker of voltage-gated Ca2+ channels,in Purkinje cell

这个流产的项目的目的是确定一种新发现的钙通道调节因子在神经元突触可塑性中的作用。这种名为cBARP的调节因子在一些锥体神经元和小脑浦肯野细胞中高度表达。在项目的初始阶段，主要研究人员同时开发了Purkinje特异的可诱导过度表达和基于microRNA的沉默策略，以检查该蛋白对神经元钙稳态的贡献。与此同时，通过与A*Star(新加坡)的同事合作，我们开始利用一种新的条件性cBARP-KO转基因小鼠，在体内特异性地改变浦肯野神经元中cBARP的表达。这些结果表明，cBARP是神经元电压依赖性钙通道的强大调节器，如果在出生后早期就在神经元中诱导表达，将深刻影响神经元的发育。基于miRNA的沉默构建和策略使用基于重组酶的条件KO仅显示目标神经元中cBARP的表达适度降低，远远低于先前在测试模型中获得的结果。这可能表明cBARP(低翻转)在浦肯野细胞中具有特殊的稳定性。不幸的疾病和贝金博士的逝世将该项目的重点从长期努力转变为在2017财年上半年内完成。

The aim of this aborted project was to determine the contribution of a newly identified regulator of calcium channels, in neuronal synaptic plasticity. The regulator, named cBARP is highly expressed in some pyramidal neurons and in cerebellar Purkinje cells. In the initial phase of the project, the main investigator developed in parallel a Purkinje-specific inducible over-expression and a microRNA-based silencing strategy, to examine the contribution of this protein to calcium homeostasis in neurons. Concomitantly, though a collaboration with colleagues at A*Star (Singapore), we started to utilize a new conditional cBARP-KO transgenic mice, for specifically altering cBARP expression in Purkinje neuron, in vivo. The results obtained indicate that cBARP is a strong regulator of voltage-dependent calcium channels in neurons and profoundly affects neuronal development if expression is induced at early post-natal stage in neurons. The MiRNA-based silencing construct and strategy using recombinase-based conditional KO only showed moderate reduction of cBARP expression in the targeted neurons, far lower than the results previously obtained in test models. This may indicates a peculiar stability of cBARP (low turn-over) in Purkinje cells. The unfortunate disease and passing-away of Dr. Beguin changed the focus of the project from a long-term effort to one to be completed within the first half of FY2017.