Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, 1365 Clifton Rd NE, C3008, Atlanta, GA, 30322, USA.
Department of Biochemistry and Winship Cancer Institute, Emory University School of Medicine, 4133 Rollins Research Building, Atlanta, GA, 30322, USA.
Sci Rep. 2022 Mar 9;12(1):3822. doi: 10.1038/s41598-022-06793-5.
Sirtuin 2 (SIRT2) is a NAD+-dependent deacetylase, which regulates multiple biological processes, including genome maintenance, aging, tumor suppression, and metabolism. While a number of substrates involved in these processes have been identified, the global landscape of the SIRT2 acetylome remains unclear. Using a label-free quantitative proteomic approach following enrichment for acetylated peptides from SIRT2-depleted and SIRT2-overexpressing HCT116 human colorectal cancer cells, we identified a total of 2,846 unique acetylation sites from 1414 proteins. 896 sites from 610 proteins showed a > 1.5-fold increase in acetylation with SIRT2 knockdown, and 509 sites from 361 proteins showed a > 1.5-fold decrease in acetylation with SIRT2 overexpression, with 184 proteins meeting both criteria. Sequence motif analyses identified several site-specific consensus sequence motifs preferentially recognized by SIRT2, most commonly KxxxxK(ac). Gene Ontology, KEGG, and MetaCore pathway analyses identified SIRT2 substrates involved in diverse pathways, including carbon metabolism, glycolysis, spliceosome, RNA transport, RNA binding, transcription, DNA damage response, the cell cycle, and colorectal cancer. Collectively, our findings expand on the number of known acetylation sites, substrates, and cellular pathways targeted by SIRT2, providing support for SIRT2 in regulating networks of proteins in diverse pathways and opening new avenues of investigation into SIRT2 function.
Sirtuin 2（SIRT2）是一种 NAD+-依赖性去乙酰化酶，它调节多种生物过程，包括基因组维护、衰老、肿瘤抑制和代谢。虽然已经确定了许多涉及这些过程的底物，但 SIRT2 乙酰基组的全局图谱尚不清楚。使用从 SIRT2 耗尽和 SIRT2 过表达 HCT116 人结肠直肠癌细胞中富集的乙酰化肽进行无标记定量蛋白质组学方法，我们从 1414 种蛋白质中鉴定出总共 2846 个独特的乙酰化位点。在 SIRT2 敲低的情况下，有 610 种蛋白质的 896 个位点的乙酰化增加了 1.5 倍以上，在 SIRT2 过表达的情况下，有 361 种蛋白质的 509 个位点的乙酰化减少了 1.5 倍以上，有 184 种蛋白质符合这两个标准。序列基序分析确定了几个由 SIRT2 优先识别的特定基序，最常见的是 KxxxxK(ac)。GO、KEGG 和 MetaCore 途径分析确定了 SIRT2 参与多种途径的底物，包括碳代谢、糖酵解、剪接体、RNA 转运、RNA 结合、转录、DNA 损伤反应、细胞周期和结直肠癌。总的来说，我们的发现扩大了已知的乙酰化位点、底物和 SIRT2 靶向的细胞途径的数量，为 SIRT2 在调节不同途径中的蛋白质网络提供了支持，并为 SIRT2 功能的研究开辟了新途径。
