REGULATION OF THE CHOLINE COTRANSPORTER

高度专业化的运输系统被描述为 胆碱能神经元的基本成分。这个运输系统是众所周知的 作为高亲和力胆碱摄取系统（HAChUS）， 共同运输钠。在胆碱能神经末梢内 乙酰胆碱（ACh）的合成是紧密耦合的活动， 胆碱共转运蛋白此外，胆碱共- 转运蛋白似乎与胆碱能神经元的活性偶联。 负责偶联的特定细胞机制 具有胆碱协同转运体活性的神经元活性是未知的。的 本次级项目所检验的假设是， 胆碱协同转运蛋白是通过转运 在细胞内区室和细胞膜之间的功能性转运蛋白。 质膜此外，据推测，这种转移 间室是由刺激依赖性细胞内 第二信使这些假设将通过以下方式得到验证： 以下一组 具体目标： 1.证明细胞内或微粒体（即囊泡） 胆碱共转运蛋白的来源及其与细胞内 转运蛋白调节质膜中的转运蛋白。 2.为了证明胆碱共- 从细胞间来源到质膜的转运蛋白。 3.探讨蛋白激酶C（PKC）在细胞凋亡调控中的作用， 胆碱协同转运蛋白的作用 4.确定直接涉及的其他第二信使系统 胆碱协同转运蛋白的调节。 5.为了确定负责直接作用的特定配体， 第二信使系统的激活涉及以下关系 胆碱协同转运蛋白

A highly specialized transport system has been characterized as an essential element of cholinergic neurons. This transport system is know as the high affinity choline uptake systems (HAChUS) and has been shown to co-transport sodium. Within the cholinergic nerve terminal acetylcholine (ACh) synthesis is tightly coupled to the activity of the choline co-transporter. Moreover, the activity of the choline co- transporter appears coupled to the activity of the cholinergic neuron. The specific cellular mechanism responsible for the coupling of neuronal activity with choline cotransporter activity is unknown. The hypothesis under test in this subproject is that the activity of the choline cotransporter is regulated via the transfer of packages of functional transporters between an intracellular compartment and the plasma membrane. Furthermore, it is hypothesized that this transfer between compartments is mediated by stimulus dependent intracellular second messengers. These hypotheses will be validated by accomplishing the following set of Specific Aims: 1. To demonstrate and intracellular or microsomal (i.e. vesicular) source of choline co-transporters and the relationship of intracellular transporters to the regulation of transporters in the plasma membrane. 2. To demonstrate the translocation of a pool of choline co- transporters from an intercellular source to the plasma membrane. 3. To determine the role of protein kinase C (PKC) in the regulation of the choline co-transporter. 4. To determine the other second messenger system(s) directly involved in the regulation of the choline cotransporter. 5. To determine the specific ligands responsible for the direct activation of the second messenger systems involve in the relation of the choline co-transporter.