THE ROLE OF DARPP-32, CK1, & CK2 IN MEDIATING THE MOLECULAR & BEHAVIORAL EFFECT

毒瘾被认为是一种扰乱大脑自然奖赏系统的疾病。众所周知， 滥用药物通过干扰多巴胺能神经传递发挥作用。它已经被展示了 例如，多巴胺能系统在与奖励相关的行为中发挥着重要作用。的主要目标是 这个项目是为了确定DARPP-32是通过什么机制整合在上游的关键磷蛋白 受酪蛋白激酶1(CK1)和酪蛋白激酶2(CK2)调节的多巴胺能信号介导了这种效应 滥用药物和精神刺激剂。使用磷酸化的DARPP-32抗体和DARPP-32 我们已经证明了DARPP-32磷酸化状态的变化 以应对体内给药的滥用。我们已经确定了四种调节的磷酸化 将DARPP-32转化为主要蛋白磷酸酶(PP-1)的有效抑制剂或转化为有效的 一种关键激酶(PKA)的抑制物，取决于磷酸化的结合部位。其中两个站点是 CK1和CK2的目标。纹状体是多巴胺能功能的主要大脑区域，由以下部分组成 两个重要的异质神经元细胞群。这两个神经元细胞群的重要性 对于上面提到的观察结果是未知的。因此，我们将扩展我们之前的体内研究，以包括 DARPP-32磷酸化的细胞类型特异性研究。此外，长期接触滥用药物有 已被证明可以诱导基因表达的变化，而这些基因表达与可卡因的奖赏效应有关。我们会 以特定细胞类型进行研究，以确定每种细胞类型对这些指标的相对贡献 效果。目的研究急性和慢性给药对细胞类型的特异性影响 滥用药物对DARPP-32磷酸化和信使核糖核酸翻译的影响。我们将进一步调查 CK1和CK2通过DARPP-32调节药物滥用效应的机制 转基因小鼠。此外，我们还将研究新的CK1和CK2相互作用蛋白 寻找可能的上游监管者。目标二和目标三将描述CK1和CK1的作用 CK2在药物滥用行为中的作用。综上所述，这些研究将提供有关 DARPP-32磷酸化和DARPP-32以细胞类型特异性方式介导的转录事件，以及 还论述了CK1和CK2在药物滥用行为中的重要性及其调控。

Drug addiction is considered as a disease perturbing the brain's natural reward system. It is well established that drugs of abuse exert their effects by interfering with dopaminergic neurotransmission. It has been shown for example that the dopaminergic system plays an important role in reward-related behaviours. The major goal of this Project is to determine by which mechanisms DARPP-32, a crucial phosphoprotein integrating upstream dopaminergic signals and regulated by casein kinase 1 (CK1) and casein kinase 2 (CK2), mediates the effects of drugs of abuse and psychostimulants. Using phospho-specific DARPP-32 antibodies and DARPP-32 phospho-site mutant mice, we have demonstrated that changes in the phosphorylation state of DARPP-32 occur in response to the in vivo administration of drugs of abuse. We have identified four regulatory phosphorylation sites converting DARPP-32 either into a potent inhibitor of a major protein phosphatase (PP-1), or into a potent inhibitor of a crucial kinase (PKA) depending of the combination of sites phosphorylated. Two of these sites are targeted by CK1 and CK2. The striatum, the major brain region for the dopaminergic functions, is composed of two important heterogeneous neuronal cell populations. The importance of these two neuronal cell populations for the above mentioned observations is unknown. We will thus extend our previous in vivo studies to include cell-type specific studies of DARPP-32 phosphorylation. In addition, chronic exposure to drugs of abuse has been shown to induce changes in gene expression that are involved in the rewarding effects of cocaine. We will perform studies in a cell-type specific manner to determine the relative contribution of each cell-type to these effects. Aim I will be the characterization of cell-type specific effects of acute and chronic administration of drugs of abuse on DARPP-32 phosphorylation and on mRNA translation. We will further investigate the mechanism by which CK1 and CK2 modulate the effects of drugs of abuse through DARPP-32 using genetically modified mice. In addition we will characterize novel CK1 and CK2 interacting proteins in a search to find putative upstream regulators. Aim II and Aim III will be the characterization of the role of CK1 and CK2 in the actions of drugs of abuse. Taken together, these studies will provide detailed information on DARPP-32 phosphorylation and DARPP-32-mediated transcriptional events in a cell type specific manner, and also on the importance and the regulation of CK1 and CK2 in the actions of drugs of abuse.