REGULATION OF NEUROPEPTIDE BIOSYNTHESIS

该项目的长期目标是应用 生物化学研究神经系统基因是如何表达的 并受到监管。神经系统由许多神经元组成，这些神经元 以精确的方式相互连接。的多样性 神经元及其相互作用的性质表明，特定的基因 或者一组基因在一些神经元中被激活，而在另一些神经元中不被激活。其中之一 这项建议的具体目的是为了加深对 与基因表达和调控相关的分子事件 哺乳动物中含量最丰富、分布最广的神经肽 神经系统，神经肽Y。NPY基因的特定区域 负责表达、组织特异性表达和对 神经生长因子将用分子和生化方法进行解剖 接近了。 大多数神经肽和大量蛋白质都经历翻译后 需要有限的蛋白质分解的加工。至少两个(而且通常是 更重要的是，酶似乎在它们的加工过程中起作用：1)类胰蛋白酶 识别蛋白质和神经肽前体的蛋白水解酶 其中存在两个相邻的碱性残基；以及2)羧基肽酶 类B酶，它将C-末端的碱性残基从C- 由有限的蛋白质分解形成的中间产物的末端。这些 这个提议的第二个目的是更好地定义分子事件 与蛋白质和蛋白质前体的有限蛋白质分解有关 神经肽。我们的实验室已经鉴定并测序了一个全长的 羧基肽酶B类加工酶(简称为 羧肽酶H[CPH])。我们已经证明了羧基肽酶H是 作为前体合成，这是报道的第一个例子 作为前体合成的蛋白水解酶。这个 过程中产生的中间体的鉴定和表征 该前驱体的加工也是这项工作的目标之一。在……里面 此外，编码羧基肽酶H的基因应该包含序列 这导致了它在激素产生细胞中的选择性表达。 因此，我们想要确定和描述这些区域的特征 基因。

The long range objective of this project is to apply the techniques of biochemistry to investigate how genes of the nervous system are expressed and regulated. The nervous system is composed of many neurons which interconnect with one another in a precis manner. The diversity of neurons and the nature of their interactions suggest that specific genes or sets of genes are activated in some neurons and not in others. One of the specific aims of this proposal is to develop a better understanding of the molecular events associated with the expression and regulation of the most abundant and widely distributed neuropeptide the mammalian nervous system, neuropeptide Y. The specific regions of the NPY gene responsible for expression, tissue-specific expression, and response to nerve growth factor will be dissected using molecular and biochemical approaches. Most neuropeptides and numerous proteins undergo post-translational processing which requires limited proteolysis. At least two (and often more) enzymes appear to function in their processing: 1) a trypsin-like protease, which recognizes precursors to both proteins and neuropeptides where two adjacent basic residues are present; and 2) a carboxypeptidase B-like enzyme, which removes the C-terminal basic residues form the C- terminus of intermediates which are formed by limited proteolysis. These second aim of this proposal is to better define the molecular events associated with the limited proteolysis of precursors to proteins and neuropeptides. Our laboratory has identified and sequenced a full-length clone of the carboxypeptidase B-like processing enzyme (referred to as carboxypeptidase H [CPH]). We have shown that carboxypeptidase H is synthesized as a precursor, which is the first reported example of a proteolytic-processing enzyme being synthesized as a precursor. The identification and characterization of the intermediates produced during the processing of this precursor is also a goal of this work. In addition, the gene encoding carboxypeptidase H should contain sequences which result in its selective expression in hormone producing cells. Therefore, we would like to identify and characterize these regions of the gene.