ADP-Ribosylation and Regulation of Cellular Functions

目前有相当令人信服的支持这一假设 ADP核糖基化对蛋白质的可逆修饰 在调节细胞功能和信号中的重要作用 真核生物中的转导。 本研究的总体目标 是在分子水平上阐明ADP的作用- 核糖基转移酶（ADPRTases）在信号转导中的作用， 调节细胞功能。 为实现这一目标， （1）了解这些酶的活性如何 调节，（2）确定蛋白质作为生理 该翻译后修饰的相关靶标，和（3） 确定这些特定蛋白质的修饰如何控制 细胞功能。 实现这些目标的进展受到了 缺乏用于研究的免疫学和分子遗传学试剂 ADP参与的修饰酶和靶蛋白， 核糖基化反应 例如，没有内源性的基因 ADPRTase尚未被克隆或测序。 同样，没有目标 已经鉴定了用于体内ADP-核糖基化的蛋白质。 一 该建议具体目标是产生免疫的和 分子遗传试剂作为探针， 围绕这些翻译后的重要问题 蛋白质的修饰。 的平行和互补目标， 这项研究是（1）产生抗体， 识别ADPRTases和ADP-核糖基化蛋白，和（2）分子 分析这些蛋白质及其基因。 %%% 许多蛋白质在合成后通过加成作用进行结构修饰 各种各样的小分子。 在某些情况下，这些修改具有 已被证明在药物的作用机制中起着关键作用。 蛋白 例如，在许多细胞对外界环境的反应中， 刺激信号转导的机制往往涉及 激活一种酶，使其增加或除去磷酸基团， 一些蛋白质。 另一种类型的蛋白质修饰是 一种叫做腺苷二磷酸核糖的分子， 维生素和糖，到特定的蛋白质。 这种化学反应 是由一种叫做腺苷二磷酸核糖基的酶进行的， 转移酶（ADPRTases）。 本研究的总体目标是 在分子水平上阐明ADP的作用- 核糖基转移酶在细胞信号转导和调控中的作用 功能协调发展的 近期目标是表征ADP 核糖基转移酶，并鉴定和表征 ADPRTases的生理学上重要的蛋白质底物。 首先，有必要发展生物化学和免疫学 工具来进行这些研究。 这项研究成果 应该是一个重要的贡献，了解 细胞对外界刺激作出反应的分子机制。

Currently there is reasonably convincing support for the hypothesis that reversible modification of proteins by ADP-ribosylation plays a significant role in regulation of cellular functions and signal transduction in eukaryotes. The overall objective of this research is to elucidate at the molecular level the role(s) of ADP- riblosyltransferases (ADPRTases) in signal transduction and regulation of cellular functions. To achieve this goal, it will be necessary to (1) understand how the activity of these enzymes is regulated, (2) identify the proteins which serve as physiologically relevant targets for this post-translational modification, and (3) determine how the modification of these specific proteins controls cellular functions. Progress toward these goals is hampered by the lack of immunological and molecular genetic reagents for studying the modifying enzymes and target proteins involved in ADP- ribosylation reactions. For example, no gene for an endogenous ADPRTase has yet been cloned or sequenced. Likewise, no target protein for in vivo ADP-ribosylation has been identified. One specific goal of this proposal is to generate immunological and molecular genetic reagents to use as probes in addressing some of the important questions surrounding these post-translational modifications of proteins. The parallel and complementary aims of this study are (1) generation of antibodies that specifically recognize ADPRTases and ADP-ribosylated proteins and (2) molecular analysis of these proteins and their genes. %%% Many proteins are structurally modified after synthesis by addition of various small molecules. In some cases these modifications have been shown to play a pivotal role in the mechanism of action of the protein. For example, in many cellular responses to external stimuli the mechanism of signal transduction often involves the activation of an enzyme that adds or removes a phosphate group from some protein. Another type of protein modification is the addition of a molecule, known as adenosine diphosphoribose, derived from a vitamin and a sugar, to specific proteins. This chemical reaction is carried out by an enzyme known as adenosine diphosophoribosyl- transferases (ADPRTases). The overall goal of this research is to elucidate at the molecular level the role(s) of ADP- ribosyltransferases in signal transduction and regulation of cell functions. The near term objectives are to characterize ADP ribosyltransferases and to identify and characterize the physiologically important protein substrates of the ADPRTases. First it is necessary to develop biochemical and immunological tools to proceed with these studies. The results of this research should be an important contribution to understanding of the molecular mechanisms by which cells respond to external stimuli.