CHARACTERIZATION OF MAMMALIAN ADP-RIBOSLYTRANSFERASES

哺乳动物 ADP-核糖转移酶的表征

• 批准号: 2576748
• 负责人: J MOSS
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2576748
• 关键词: ADP ribosylation; adenine phosphoribosyltransferase; arginine; bacterial toxins; biochemical evolution; enzyme activity; enzyme mechanism; enzyme structure; human tissue; laboratory mouse; laboratory rabbit; lymphoma; molecular cloning; protein sequence; striated muscles

Mono-ADP-ribosylation, a posttranslational modification of proteins in which the ADP-ribose moiety of NAD is transferred to proteins, is responsible for the toxicity of some bacterial toxins (e.g., cholera toxin, pertussis toxin). NAD:arginine ADP-ribosyltransferases cloned from human and rabbit skeletal muscle and from mouse lymphoma cells (Yac- 1 ADP-ribosyltransferase), are glycosylphosphatidylinositol (GPI)- anchored and have similar enzymatic and physical properties. A second ADP-ribosyltransferase (Yac-2) was cloned from mouse lymphoma cells, which differs in properties from the previously identified eukaryotic transferases. The nucleotide and deduced amino acid sequences of the Yac-1 and Yac-2 transferases are 58 and 33% identical, respectively. The Yac-2 protein is membrane-bound but, unlike the Yac-1 enzyme, appears not to be GPI-anchored. The Yac-1 and Yac-2 enzymes, expressed as glutathione-S-transferase fusion proteins in E. coli, were used to compare their ADP-ribosyltransferase and NAD glycohydrolase activities. Using agmatine as the ADP-ribose acceptor, the Yac-1 enzyme was predominantly an ADP-ribosyltransferase, whereas the transferase and NAD glycohydrolase activities of the recombinant Yac-2 protein were similar. The deduced amino acid sequence of the Yac-2 transferase contained consensus regions common to several bacterial toxin and mammalian transferases and NAD glycohydrolases, consistent with the hypothesis that there is a common mechanism of NAD binding and catalysis among ADP- ribosyltransferases.

单 ADP 核糖基化，蛋白质的翻译后修饰 NAD 的 ADP-核糖部分被转移到蛋白质上，是 造成某些细菌毒素（例如霍乱）的毒性 毒素、百日咳毒素）。 NAD：克隆的精氨酸 ADP-核糖基转移酶 来自人和兔骨骼肌以及小鼠淋巴瘤细胞（Yac- 1 ADP-核糖基转移酶），是糖基磷脂酰肌醇（GPI）- 锚定并具有相似的酶学和物理特性。 一秒钟 ADP-核糖基转移酶 (Yac-2) 从小鼠淋巴瘤细胞中克隆， 其特性与之前鉴定的真核生物不同 转移酶。 核苷酸和推导的氨基酸序列 Yac-1 和 Yac-2 转移酶分别有 58% 和 33% 相同。 这 Yac-2 蛋白是膜结合蛋白，但与 Yac-1 酶不同，它似乎不是膜结合蛋白 以 GPI 为锚定。 Yac-1 和 Yac-2 酶，表示为 大肠杆菌中的谷胱甘肽-S-转移酶融合蛋白，用于 比较它们的 ADP-核糖基转移酶和 NAD 糖水解酶活性。 使用胍丁胺作为 ADP-核糖受体，Yac-1 酶 主要是 ADP-核糖基转移酶，而转移酶和 NAD 重组Yac-2蛋白的糖水解酶活性相似。 推导的Yac-2转移酶氨基酸序列包含 几种细菌毒素和哺乳动物共有的共有区域 转移酶和 NAD 糖水解酶，与假设一致 ADP-之间存在共同的 NAD 结合和催化机制 核糖基转移酶。