近日，美国霍普金斯大学Anthony K. L. Leung和Marc M. Greenberg研究组利用基于光亲和力的蛋白质组学鉴定多聚ADP-核糖结合蛋白。 这一研究成果发表在2021年2月17日出版的《美国化学会杂志》上。

在本研究中，该课题组合成了一种能捕获和分离PAR结合物的PAR光亲和探针。他们的方法识别了数十种已知的PAR结合蛋白和数百种参与DNA修复、RNA处理和代谢的新候选蛋白。通过pull-down和/或电泳迁移率分析确认了8个候选的PAR结合。

使用确定长度的PAR探针，课题组研究人员检测到相比于8-mer优先结合40-mer的PAR的蛋白质，这表明聚合物的长度可能调节PAR信号通路的结果和时间。

这项研究首次对PAR结合蛋白进行了普查，提供了长度选择性PAR结合的蛋白质组学分析，并将PAR结合与RNA代谢和生物分子缩合物的形成联系起来。

据了解，多聚ADP-核糖修饰蛋白质是DNA损伤反应的重要组成部分。四种PAR合成抑制剂最近被批准用于治疗乳腺癌、卵巢癌和前列腺癌。尽管PAR具有临床意义，但对其功能的分子理解，包括其结合伙伴，仍不完全。

附：英文原文

Title: Identifying Poly(ADP-ribose)-Binding Proteins with Photoaffinity-Based Proteomics

Author: Morgan Dasovich, Morgan Q. Beckett, Scott Bailey, Shao-En Ong, Marc M. Greenberg, Anthony K. L. Leung

Issue&Volume: February 17, 2021

Abstract: Post-translational modification of proteins with poly(ADP-ribose) (PAR) is an important component of the DNA damage response. Four PAR synthesis inhibitors have recently been approved for the treatment of breast, ovarian, and prostate cancers. Despite the clinical significance of PAR, a molecular understanding of its function, including its binding partners, remains incomplete. In this work, we synthesized a PAR photoaffinity probe that captures and isolates endogenous PAR binders. Our method identified dozens of known PAR-binding proteins and hundreds of novel candidates involved in DNA repair, RNA processing, and metabolism. PAR binding by eight candidates was confirmed using pull-down and/or electrophoretic mobility shift assays. Using PAR probes of defined lengths, we detected proteins that preferentially bind to 40-mer versus 8-mer PAR, indicating that polymer length may regulate the outcome and timing of PAR signaling pathways. This investigation produces the first census of PAR-binding proteins, provides a proteomics analysis of length-selective PAR binding, and associates PAR binding with RNA metabolism and the formation of biomolecular condensates.

DOI: 10.1021/jacs.0c12246

Source: https://pubs.acs.org/doi/10.1021/jacs.0c12246