Department of Genetics, Harvard Medical School and Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Department of Genetics, Harvard Medical School and Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Cell. 2018 Jun 14;173(7):1622-1635.e14. doi: 10.1016/j.cell.2018.04.028. Epub 2018 May 17.
Degrons are minimal elements that mediate the interaction of proteins with degradation machineries to promote proteolysis. Despite their central role in proteostasis, the number of known degrons remains small, and a facile technology to characterize them is lacking. Using a strategy combining global protein stability (GPS) profiling with a synthetic human peptidome, we identify thousands of peptides containing degron activity. Employing CRISPR screening, we establish that the stability of many proteins is regulated through degrons located at their C terminus. We characterize eight Cullin-RING E3 ubiquitin ligase (CRL) complex adaptors that regulate C-terminal degrons, including six CRL2 and two CRL4 complexes, and computationally implicate multiple non-CRLs in end recognition. Proteome analysis revealed that the C termini of eukaryotic proteins are depleted for C-terminal degrons, suggesting an E3-ligase-dependent modulation of proteome composition. Thus, we propose that a series of "C-end rules" operate to govern protein stability and shape the eukaryotic proteome.
肽段是介导蛋白质与降解机制相互作用以促进蛋白水解的最小元件。尽管它们在蛋白质稳态中起着核心作用，但已知的肽段数量仍然很少，并且缺乏一种简便的鉴定它们的技术。我们采用了一种将全局蛋白稳定性 (GPS) 分析与合成的人类肽组学相结合的策略，鉴定出了数千种含有肽段活性的肽段。通过 CRISPR 筛选，我们确定许多蛋白质的稳定性是通过位于其 C 末端的肽段来调节的。我们鉴定了八个 Cullin-RING E3 泛素连接酶 (CRL) 复合物衔接子，它们可以调节 C 末端肽段，包括六个 CRL2 和两个 CRL4 复合物，并通过计算方法推测了多个非 CRL 在末端识别中的作用。蛋白质组分析显示，真核蛋白的 C 末端缺乏 C 末端肽段，这表明 E3 连接酶依赖性地调节蛋白质组组成。因此，我们提出了一系列“C 末端规则”来控制蛋白质稳定性并塑造真核生物蛋白质组。
