Proteomics Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK.
Nat Commun. 2021 Oct 8;12(1):5893. doi: 10.1038/s41467-021-26172-4.
Despite the involvement of Poly(ADP-ribose) polymerase-1 (PARP1) in many important biological pathways, the target residues of PARP1-mediated ADP-ribosylation remain ambiguous. To explicate the ADP-ribosylation regulome, we analyze human cells depleted for key regulators of PARP1 activity, histone PARylation factor 1 (HPF1) and ADP-ribosylhydrolase 3 (ARH3). Using quantitative proteomics, we characterize 1,596 ADP-ribosylation sites, displaying up to 1000-fold regulation across the investigated knockout cells. We find that HPF1 and ARH3 inversely and homogenously regulate the serine ADP-ribosylome on a proteome-wide scale with consistent adherence to lysine-serine-motifs, suggesting that targeting is independent of HPF1 and ARH3. Notably, we do not detect an HPF1-dependent target residue switch from serine to glutamate/aspartate under the investigated conditions. Our data support the notion that serine ADP-ribosylation mainly exists as mono-ADP-ribosylation in cells, and reveal a remarkable degree of histone co-modification with serine ADP-ribosylation and other post-translational modifications.
尽管聚（ADP-核糖）聚合酶 1（PARP1）参与了许多重要的生物学途径，但 PARP1 介导的 ADP-核糖基化的靶残基仍然不清楚。为了阐明 ADP-核糖基化调控组，我们分析了 PARP1 活性的关键调节剂（组蛋白 PAR 化因子 1（HPF1）和 ADP-核糖基水解酶 3（ARH3））耗尽的人类细胞。使用定量蛋白质组学，我们对 1596 个 ADP-核糖基化位点进行了表征，这些位点在研究的敲除细胞中显示出高达 1000 倍的调节。我们发现 HPF1 和 ARH3 以相反且均匀的方式在全蛋白范围内调节丝氨酸 ADP-核糖基组，并且一致地遵守赖氨酸-丝氨酸基序，这表明靶向独立于 HPF1 和 ARH3。值得注意的是，我们在研究条件下未检测到 HPF1 依赖性靶位残基从丝氨酸到谷氨酸/天冬氨酸的转换。我们的数据支持丝氨酸 ADP-核糖基化主要以单 ADP-核糖基化形式存在于细胞中的观点，并揭示了组蛋白与丝氨酸 ADP-核糖基化和其他翻译后修饰的显著程度的共修饰。
