Transporter maintenance of dopamine homeostasis

描述（由申请人提供）： 多巴胺转运蛋白（DAT）是从突触间隙中清除多巴胺的主要机制。一旦被DAT吸收，DA可以被酶促降解，或被囊泡单胺转运蛋白（VMAT2）回收并重新包装成囊泡。这两种蛋白质DAT和VMAT2的协同相互作用导致多巴胺能神经元中的DA稳态。这些蛋白质中的任何一种的功能或表达不当都会导致体内平衡改变，并与许多临床病理学相关，包括抑郁症和帕金森病。特别令人感兴趣的是由于药物滥用引起的调节，因为DAT是可卡因和安非他明等精神兴奋剂的主要作用部位。因此，本提案的目标是研究在永生化细胞系中共表达的DAT和VMAT2如何相互作用以维持稳态，以及它们的功能和调节如何被滥用药物改变。该提议的具体目的是：1）表征这两种蛋白质的共表达对细胞系统中DA稳态的影响，2）检查共表达对药物诱导的神经递质调节的影响，和3）确定共表达对药物诱导的活性氧簇形成的影响。

DESCRIPTION (provided by applicant): The dopamine (DA) transporter (DAT) is the primary mechanism for removing dopamine from the synaptic cleft. Once taken up by the DAT, DA can be either degraded enzymatically, or recycled and repackaged into vesicles by the vesicular monoamine transporter (VMAT2). It is the synergistic interaction of these two proteins, DAT and VMAT2, that lead to DA homeostasis in dopaminergic neurons. Improper function or expression of either of these proteins results in altered homeostasis and has been associated with many clinical pathologies, including depression and Parkinson's disease. Of particular interest is regulation due to substance abuse, since the DAT is a primary site of action of psychostimulants such as cocaine and amphetamine. Therefore, the goals of this proposal are to examine how DAT and VMAT2, co-expressed in immortalized cell lines, interact to maintain homeostasis, and how their function and regulation is altered by drugs of abuse. The specific aims of this proposal are to: 1) characterize the effect of co-expression of these two proteins on DA homeostasis in a cell system, 2) examine the effect co-expression on drug-induced neurotransmitter regulation, and 3) determine the effect of co-expression on drug-induced reactive oxygen species formation.