Conserved enzymatic production and biological effect of O-acetyl-ADP-ribose by silent information regulator 2-like NAD+-dependent deacetylases
Conserved enzymatic production and biological effect of O-acetyl-ADP-ribose by silent information regulator 2-like NAD+-dependent deacetylases
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DOI：
10.1074/jbc.m111830200
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发表时间：
2002-04-12
影响因子：
4.8
通讯作者：
Denu, JM
中科院分区：
文献类型：
--
作者：
Borra, MT;O'Neill, FJ;Denu, JM
沉默信息调节因子2(Sir2)家族参与了许多细胞过程，包括组蛋白去乙酰化、基因沉默、染色体稳定性和衰老。酵母Sir2和几个同系物已被证明是依赖NAD(+)的组蛋白/蛋白质去乙酰基酶。以往的研究表明，酵母酶催化一种独特的反应机制，即NAD(+)的裂解和底物的脱乙酰基与一种新的代谢产物O-乙酰-ADP-核糖的形成相耦合。我们证明了O-乙酰-ADP-核糖的产生在酵母、果蝇和人类的Sir2样酶中进化上是保守的。此外，端粒中的内源酵母Sir2复合体也能产生O-乙酰-ADP-核糖。通过使用定量微量注射试验来检测这种新发现的代谢物的可能的生物学功能(S)，我们证明了O-乙酰-腺苷二磷酸-核糖导致卵母细胞成熟的延迟/阻止，并导致卵裂球中胚胎细胞分裂的延迟/阻止。这种效应是通过注射低纳摩尔水平的活性酶来模拟的，但不是用催化受损的突变体来模拟的，这表明酶的活性对于观察到的效应是必不可少的。在无细胞卵母细胞提取物中，我们证明了细胞酶的存在，可以有效地利用O-乙酰-ADP-核糖。
Silent information regulator 2 (Sir2) family of enzymes has been implicated in many cellular processes that include histone deacetylation, gene silencing, chromosomal stability, and aging. Yeast Sir2 and several homologues have been shown to be NAD(+)-dependent histone/protein deacetylases. Previously, it was demonstrated that the yeast enzymes catalyze a unique reaction mechanism in which the cleavage of NAD(+) and the deacetylation of substrate are coupled with the formation of O-acetyl-ADP-ribose, a novel metabolite. We demonstrate that the production of O-acetyl-ADP-ribose is evolutionarily conserved among Sir2-like enzymes from yeast, Drosophila, and human. Also, endogenous yeast Sir2 complex from telomeres was shown to generate O-acetyl-ADP-ribose. By using a quantitative microinjection assay to examine the possible biological function(s) of this newly discovered metabolite, we demonstrate that O-acetyl-ADP-ribose causes a delay/block in oocyte maturation and results in a delay/block in embryo cell division in blastomeres. This effect was mimicked by injection of low nanomolar levels of active enzyme but not with a catalytically impaired mutant, indicating that the enzymatic activity is essential for the observed effects. In cell-free oocyte extracts, we demonstrate the existence of cellular enzymes that can efficiently utilize O-acetyl-ADP-ribose.