SGER: Role of CREB in Regulating Neuropeptide Synthesis

PI: Nancy Lynne WayneNSF SGER提案# 0314007标题：“CREB在调节神经肽合成中的作用”神经肽负责控制生理和行为的不同方面，包括身体生长，饮食，性等。本提案的主要目标是了解利用控制软体动物繁殖的神经元控制神经肽激素合成的细胞机制。该实验室早期的研究表明，生殖神经内分泌袋细胞神经元（bcn）的电刺激导致神经肽产卵激素（ELH）的大量分泌。通过上调ELH合成来补充ELH的释放量，以牺牲BCNs中大多数其他蛋白质为代价。结果表明，bcn的电刺激刺激了一种新的蛋白质合成途径，该途径涉及ELH mRNA上称为内部核糖体进入位点（IRES）的特殊编码。这类似于病毒在感染后控制细胞内蛋白质合成的方式，并且不被认为在细胞系统中起生理作用。拟议研究的目的是了解bcn的刺激如何激活ELH mRNA上的IRES。基于早期的工作，我们假设环AMP第二信使通路（通过环AMP反应元件结合蛋白，CREB）在介导电刺激对IRES激活的影响中发挥重要作用，从而导致ELH合成的上调。为了验证这一假设，CREB的表达将被RNA抑制所阻碍，并将记录对ELH合成和IRES激活的电激发的影响。该实验结合了分子、生化、电生理和光学成像技术。预计抑制CREB将阻止IRES的电激活和随后的ELH合成上调。这项工作是思考细胞系统如何调节蛋白质合成的一种全新方式的前沿

PI: Nancy Lynne WayneNSF SGER proposal #031407Title: "Role of CREB in regulating neuropeptide synthesis"Neuropeptides are responsible for controlling different aspects of physiology and behavior including body growth, eating, drinking, sex, etc. The broad goal of this proposal is to understand cellular mechanisms controlling synthesis of a neuropeptide hormone using neurons that control reproduction in the mollusk Aplysia. Earlier studies from this laboratory showed that electrical excitation of the reproductive neuroendocrine bag-cell neurons (BCNs) led to large amounts of secretion of the neuropeptide egg laying hormone (ELH). The releasable amount of ELH was replenished by upregulating ELH synthesis at the expense of most other proteins in the BCNs. It was revealed that electrical excitation of the BCNs stimulated a novel protein-synthetic pathway involving a special code on ELH mRNA called an internal ribosomal entry site (IRES). This is similar to how viruses control protein synthesis in cells following infection, and was not thought to play a physiological role in cellular systems. The aim of the proposed studies is to understand how stimulation of the BCNs activates the IRES on ELH mRNA. Based on earlier work, it is hypothesized that the cyclic AMP second messenger pathway (via cyclic AMP response-element binding protein, or CREB) is playing an important role in mediating the effects of electrical excitation on IRES activation, leading to upregulation of ELH synthesis. To test this hypothesis, expression of CREB will be obstructed by RNA inhibition, and the effects on electrical excitation of ELH synthesis and IRES activation will be documented. This experiment uses a combination of molecular, biochemical, electrophysiological, and optical imaging techniques. It is expected that inhibition of CREB will prevent electrical activation of the IRES and subsequent upregulation of ELH synthesis. This work is at the forefront of a completely new way of thinking about the way that cellular systems can regulate synthesis of proteins