ADP-RIBOSYLATION CYCLES

单ADP-核糖基化是蛋白质的可逆修饰，NAD：精氨酸ADP-核糖基转移酶和ADP-核糖基精氨酸水解酶催化ADP-核糖基化循环的相对臂。先前的研究已经检查了小鼠ADP-核糖基精氨酸水解酶基因的结构。5侧翼启动子区显示在-199至-89处具有关键调节元件。发现该区域在许多细胞系中起作用，表明需要相对常见的转录因子。启动子的进一步突变分析和电泳迁移率变动测定鉴定了阳性GC盒元件（-107- -95）;使用超变动测定，发现Sp1和Sp3与该基序结合。在使用果蝇SL 2细胞，缺乏内源性Sp1，Sp1的cotransfertility实验中，发现反式激活ADP-核糖基精氨酸水解酶启动子的方式依赖于一个完整的Sp1结合基序的存在。启动子的活性模式和参与Sp1转录因子是一致的，与以前的观察显示广泛的水解酶在哺乳动物组织中的表达。- ADP-核糖基化，ADP-核糖基精氨酸水解酶

Mono-ADP-ribosylation is a reversible modification of proteins, with NAD: arginine ADP-ribosyltransferases and ADP-ribosylarginine hydrolases catalyzing opposing arms of an ADP-ribosylation cycle. Prior studies have examined the structure of the mouse ADP-ribosylarginine hydrolase gene. The 5 flanking promoter region was shown to have a critical regulatory element at -199 to -89. This region was found to function in a number of cell lines, suggesting the requirement for a relatively common transcription factor. Further mutational analysis of the promoter and electrophoretic mobility shift assays identified a positive GC-box element (-107- -95); using supershift assays, Sp1 and Sp3 were found to bind to this motif. In cotransferction experiments using Drosophila SL2 cells, which lack endogenous Sp1, Sp1 was found to transactivate the ADP-ribosylarginine hydrolase promoter in a manner dependent on the presence of an intact Sp1-binding motif. The promoter activity pattern and involvement of Sp1 transcription factors are consistent with prior observations showing widespread hydrolase expression in mammalian tissues. - ADP-ribosylation, ADP- ribosylarginine hydrolase