STRIATAL PHOSPHOPROTEINS AND THE ACTIONS OF PSYCHOSTIMULANTS

大量证据表明，精神运动兴奋剂(如可卡因和可卡因)的急性和慢性作用 安非他明)，以及其他滥用药物，涉及调节中脑边缘神经传递和 黑质纹状体多巴胺系统。我们之前的研究表明，cAMP依赖的底物家族 蛋白激酶，包括DARPP-32、RCS(钙调蛋白信号调节因子，以前称为ARPP-21)，以及 ARPP-16在包括新纹状体和伏隔核在内的基底节中高度丰富。以前的研究 最近的研究表明，DARPP-32的一个关键靶点是丝氨酸/苏氨酸蛋白磷酸酶，即PPL。 发现RCS与钙结合蛋白钙调蛋白相互作用，进而调节丝氨酸/苏氨酸 蛋白磷酸酶，钙调神经磷酸酶(或PP2B)。在其他研究中，我们发现ARPP-16可能调节 GAP-43mRNA的稳定性。在项目III中，我们建议研究RCS和ARPP-16在调解或 调节精神刺激剂的作用。此外，我们建议研究pp1的三种异构体的作用。 (PP1α、β和伽马)在精神刺激剂的作用中。具体目标是： 目的I：RCS的特征-我们将分析RCS基因敲除小鼠的几个方面的动物行为和 由精神刺激剂调节的生理学。这些研究将包括急性和慢性运动兴奋剂。 可卡因和苯丙胺在rcs突变小鼠体内的特性和药物增强特性。我们还将描述 RCS的分子靶点，可能参与调节精神刺激剂的作用。研究将包括 RCS的分析和钙调神经磷酸酶的调节，以及RCS和其他钙调蛋白结合蛋白的调节。 目的II：ARPP-16的特性-我们将在ARPP-16基因敲除小鼠中分析动物的几个方面 心理刺激剂调节的行为和生理。这些研究将包括急性和慢性运动兴奋剂。 可卡因和苯丙胺在rcs突变小鼠体内的特性和药物增强特性。我们还将 表征ARPP-16在新的位点上的磷酸化调节，并研究这些位点的磷酸化 对心理刺激治疗的反应。 目的III：PP1亚型的特征-我们将研究PP1α、β和伽马亚型在PP1a、β和γ亚型中的作用 精神刺激剂。这些特性包括急性和慢性运动刺激剂特性以及药物增强特性 可卡因和苯丙胺在RCS突变小鼠中的作用。 我们的研究成果将补充本计划项目资助的其他项目。总而言之，这些研究将 希望能有助于阐明滥用药物在大脑中起作用的生化途径，并对 更有可能开发出可防止或逆转体内分子适应的治疗剂 这些小路。

Considerable evidence indicates that the acute and chronic actions of psychomotor stimulants (e.g. cocaine and amphetamine), as well as of other drugs of abuse, involve modulation of neurotransmission in mesolimbic and nigrostriatal dopamine systems. Our previous studies have revealed that a family of substrates for cAMP-dependent protein kinase, including DARPP-32, RCS (Regulator of Calmodulin Signaling, previously termed ARPP-21), and ARPP-16, are highly enriched in the basal ganglia, including the neostriatum and nucleus accumbens. Previous studies have indicated that a critical target for DARPP-32 is the serine/threonine protein phosphatase, PPL In recent studies we have found that RCS interacts with the Ca2+-binding protein calmodulin and in turn regulates the serine/threonine protein phosphatase, calcineurin (or PP2B). In other studies, we have found that ARPP-16 is likely to regulate the stability of GAP-43 mRNA. In Project III, we propose to study the role(s) of RCS and ARPP-16 in mediating or modulating the actions of psychostimulants. In addition, we propose to study the roles of the three isoforms of PP1 (PP1alpha, beta and gamma) in the actions of psychostimulants. The Specific Aims are: Aim I: Characterization of RCS - We will analyze in RCS knockout mice, several aspects of animal behavior and physiology that are modulated by psychostimulants. These studies will include acute and chronic motor-stimulant properties and drug reinforcing properties of cocaine and amphetamine in RCS mutant mice. We will also characterize molecular targets for RCS that may be involved in mediating the actions of psychostimulants. Studies will include analysis of RCS and regulation of calcineurin, and of RCS and regulation of other calmodulin-binding proteins. Aim II: Characterization of ARPP-16 - We will analyze in ARPP-16 knockout mice, several aspects of animal behavior and physiology that are modulated by psychostimulants. These studies will include acute and chronic motorstimulant properties and drug reinforcing properties of cocaine and amphetamine in RCS mutant mice. We will also characterize the regulation of ARPP-16 by phosphorylation at novel sites and study the phosphorylation of these sites in response to psychostimulant treatment. Aim III: Characterization of PP1 isoforms - We will investigate the role of PP1alpha, beta and gamma isoforms in the actions of psychostimulants. These will include acute and chronic motor-stimulant properties and drug reinforcing properties of cocaine and amphetamine in RCS mutant mice. Results from our studies will complement other Projects of this Program Project grant. Together, these studies will hopefully lead to elucidation of the biochemical pathways through which drugs of abuse act in the brain, and to an increased likelihood that therapeutic agents will be developed that will prevent or reverse molecular adaptations within these pathways.