Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan, ROC.
Cell Mol Life Sci. 2012 Feb;69(4):641-50. doi: 10.1007/s00018-011-0771-x. Epub 2011 Jul 28.
In the cell, many small endogenous metabolic molecules are involved in distinct cellular functions such as modulation of chromatin structure and regulation of gene expression. O-acetyl-ADP-ribose (AAR) is a small metabolic molecule that is generated during NAD-dependent deacetylation by Sir2. Sir2 regulates gene expression, DNA repair, and genome stability. Here, we developed a novel chromatin affinity-precipitation (ChAP) method to detect the chromatin fragments at which small molecules interact with binding partners. We used this method to demonstrate that AAR associated with heterochromatin. Moreover, we applied the ChAP method to whole genome tiling array chips to compare the association of AAR and Sir2. We found that AAR and Sir2 displayed similar genomic binding patterns. Furthermore, we identified 312 potential association cluster regions of AAR. The ChAP assay may therefore be a generally useful strategy to study the small molecule association with chromosomal regions. Our results further suggest that the small metabolic molecule AAR associates with silent chromatin regions in a Sir2-dependent manner and provide additional support for the role of AAR in assembly of silent chromatin.
在细胞中，许多小型内源性代谢分子参与不同的细胞功能，如染色质结构的调节和基因表达的调控。O-乙酰-ADP-核糖 (AAR) 是一种小分子代谢物，在 NAD 依赖性去乙酰化过程中由 Sir2 产生。Sir2 调节基因表达、DNA 修复和基因组稳定性。在这里，我们开发了一种新的染色质亲和沉淀 (ChAP) 方法来检测小分子与结合伴侣相互作用的染色质片段。我们使用这种方法证明了 AAR 与异染色质相关。此外，我们将 ChAP 方法应用于全基因组平铺芯片，以比较 AAR 和 Sir2 的结合。我们发现 AAR 和 Sir2 显示出相似的基因组结合模式。此外，我们鉴定了 312 个潜在的 AAR 关联簇区域。因此，ChAP 测定可能是一种研究小分子与染色体区域相互作用的通用策略。我们的结果进一步表明，小分子代谢物 AAR 以 Sir2 依赖的方式与沉默染色质区域相关联，并为 AAR 在沉默染色质组装中的作用提供了额外的支持。
