SUBCELLULAR LOCALIZATION OF MRNAS IN MAMMALIAN NEURONS

描述(研究人员摘要)：神经元发育已经 通过检查过程路径发现和对调节器的响应进行研究 过程产生的结果。在发育中和成熟的神经元中， 神经元突起的功能对可塑性能力至关重要 细胞的数量。神经元突起是一种特殊的细胞结构 它的功能是神经元的极性是由 来自突触前细胞的信息在输出时通过树突到达 突触后细胞通常通过轴突的功能发生。 这些神经元结构中的蛋白质的特征一直是 深入研究的领域，产生的信息表明， 在这个过程中，细胞蛋白质得到了丰富。这种浓缩很可能 导致这些细胞结构的特殊功能。 在过去的十年中，一些mRNA同样被本地化到 树枝状的过程类和一些mRNAs已经被证明是 存在于特殊神经细胞类型的轴突中。与 这些基因的发现及其超微结构定位 核糖体到树突，可以合理地假设局部蛋白质 合成可能有助于树突的功能。最近， 这些研究人员已经证明蛋白质合成确实存在。 在海马神经元的单个树突和生长锥体中。AS 他们对此中存在的mRNA的初步调查的一部分 在亚细胞站点上，他们意外地发现编码cAMP的mRNA 反应元件结合蛋白(CREB)存在于发育中 树枝状结构。他们进一步表明，这种CREB mRNA是翻译的 转化成CREB蛋白，这种CREB可以与DNA和荧光结合 CREB被扩散到这些突起，移动到细胞核。 这些数据表明了CREB和其他转录的关键作用 神经过程中可能产生的因素，在发育过程中 称为核印迹的过程，它促进了直接 树突状环境与细胞核之间的联系。 在这份修订后的拨款申请中，他们建议将 CREB在神经元突起中的生物化学及其在脑内的潜在作用 核印记通过确定翻译和后处理是否- 定位于神经元的CREB的跨国加工 突触信号改变了这一过程。因为潜在的 考虑到这一观察结果的重要性，他们进一步建议延长 确定分子参与者的核印迹概念 在这个调控过程中，通过做一个详细的表达谱 应用单细胞核糖核酸技术在“发育”过程中的树突状生长锥 扩增技术和DNA芯片(筛查14,000人 不同的RNA同时)以及一种新型的差异显示 他们最近制定的协议。

DESCRIPTION (Investigator's Abstract): Neuronal development has been studied by examining process pathfinding and responses to modulators of process outgrowth. In both the developing and mature neuron the functioning of neuronal processes is critical to the plasticity capacity of the cells. Neuronal processes are specialized cellular structures which function such that neuronal polarity is established with information from presynaptic cells arriving via dendrites while output to post-synaptic cells generally occurs via functioning of the axon. Characterization of proteins in these neuronal structures has been an area of intense study yielding information showing that particular cellular proteins are enriched in the processes. This enrichment likely results in the specialized functioning of these cellular structures. Over the last decade a handful of mRNAs have likewise been localized to the dendritic class of processes and a few mRNAs have been shown to be present in axons of specialized neuronal cell types. With the discovery of these mRNAs and the ultrastructural localization of ribosomes to dendrites it was reasonable to assume that local protein synthesis may contribute to the functioning of dendrites. Recently, these investigators have proven that protein synthesis does indeed occur in individual dendrites and growth cones of hippocampal neurons. As part of their preliminary survey of mRNAs which are present in this subcellular site, they unexpectedly found that the mRNA encoding cAMP responsive element binding protein (CREB) is present in developing dendrites. They have further shown that this CREB mRNA is translated into CREB protein, that this CREB can bind to DNA and that fluorescent CREB which is diffused into these processes moves to the cell nucleus. These data suggest a critical role for CREB and other transcription factors which may be made in neuronal processes, in a developmental process called nuclear imprinting which facilitates the direct communication of dendritic environment with the nucleus of the cell. In this revised grant application, they propose to characterize the biochemistry of CREB in neuronal processes and its potential role in nuclear imprinting by determining whether the translation and post- transnational processing of the CREB that is localized in the neuronal process is altered by synaptic signaling. Because of the potential importance of this observation, they further propose to extend the concept of nuclear imprinting to determine the molecular participants in this regulatory process by doing a detailed expression profile of dendritic growth cones during "development" using the single cell aRNA amplification technology and the DNA chip (screening for 14,000 different mRNAs simultaneously) as well as a novel differential display protocol they have recently developed.