Identification and characterization of a mammalian 39-kDa poly(ADP-ribose) glycohydrolase
Identification and characterization of a mammalian 39-kDa poly(ADP-ribose) glycohydrolase
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DOI：
10.1074/jbc.m510290200
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发表时间：
2006-01-13
影响因子：
4.8
通讯作者：
Moss, J
中科院分区：
文献类型：
--
作者：
Oka, S;Kato, J;Moss, J
ADP-核糖基化是一种翻译后修饰，由NAD的ADP-核糖部分转移到蛋白质中引起。哺乳动物细胞含有单ADP-核糖基转移酶，可以催化ADP-核糖-（精氨酸）蛋白的形成，该蛋白可以被39-kDa ADP-核糖-（精氨酸）蛋白水解酶（ARH 1）切割，导致释放游离ADP-核糖并再生未修饰的蛋白质。参与聚腺苷二磷酸核糖基化的酶参与几个关键的生理过程，包括DNA修复、细胞分化和致癌作用。在人类基因组中已经鉴定出多种聚（ADP-核糖）聚合酶，但只有一种已知的聚（ADP-核糖）糖水解酶（PARG），它是一种111-kDa的蛋白质，可将（ADP-核糖）聚合物降解为ADP-核糖.我们在这里报告的ARH 1样蛋白，称为聚（ADP-核糖）水解酶或ARH 3，它表现出PARG活性，产生ADP-核糖从聚（ADP-核糖），但不水解ADP-核糖精氨酸，-半胱氨酸，-二苯二甲酰胺，或-天冬酰胺键的鉴定。39-kDa ARH 3与ARH 1和PARG的催化结构域共享氨基酸序列同一性。与ARH 1一样，Mg ~（2+）可增强ARH 3的活性。通过诱变（Asp（77）和Asp（78））鉴定的ARH 3中的关键邻位酸性氨基酸位于与ARH 1中活性所需的区域相似的区域，但不同于PARG催化位点中关键邻位谷氨酸的位置。所有的发现都与ARH 3具有PARG活性但结构上与PARG无关的结论一致。
ADP-ribosylation is a post-translational modification resulting from transfer of the ADP-ribose moiety of NAD to protein. Mammalian cells contain mono-ADP-ribosyltransferases that catalyze the formation of ADP-ribose-(arginine) protein, which can be cleaved by a 39-kDa ADP-ribose-( arginine) protein hydrolase (ARH1), resulting in release of free ADP- ribose and regeneration of unmodified protein. Enzymes involved in poly( ADP- ribosylation) participate in several critical physiological processes, including DNA repair, cellular differentiation, and carcinogenesis. Multiple poly( ADP- ribose) polymerases have been identified in the human genome, but there is only one known poly( ADP- ribose) glycohydrolase (PARG), a 111-kDa protein that degrades the ( ADP- ribose) polymer to ADP- ribose. We report here the identification of an ARH1-like protein, termed poly( ADP- ribose) hydrolase or ARH3, which exhibited PARG activity, generating ADP- ribose from poly( ADP- ribose), but did not hydrolyze ADP-ribose- arginine, -cysteine, -diphthamide, or -asparagine bonds. The 39-kDa ARH3 shares amino acid sequence identity with both ARH1 and the catalytic domain of PARG. ARH3 activity, like that of ARH1, was enhanced by Mg2+. Critical vicinal acidic amino acids in ARH3, identified by mutagenesis (Asp(77) and Asp(78)), are located in a region similar to that required for activity in ARH1 but different from the location of the critical vicinal glutamates in the PARG catalytic site. All findings are consistent with the conclusion that ARH3 has PARG activity but is structurally unrelated to PARG.