College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China.
Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, China.
Int J Mol Sci. 2020 Apr 21;21(8):2894. doi: 10.3390/ijms21082894.
Owing to a sessile lifestyle in nature, plants are routinely faced with diverse hostile environments such as various abiotic and biotic stresses, which lead to accumulation of free radicals in cells, cell damage, protein denaturation, etc., causing adverse effects to cells. During the evolution process, plants formed defense systems composed of numerous complex gene regulatory networks and signal transduction pathways to regulate and maintain the cell homeostasis. Among them, ubiquitin-proteasome pathway (UPP) is the most versatile cellular signal system as well as a powerful mechanism for regulating many aspects of the cell physiology because it removes most of the abnormal and short-lived peptides and proteins. In this system, the ubiquitin-conjugating enzyme (E2) plays a critical role in transporting ubiquitin from the ubiquitin-activating enzyme (E1) to the ubiquitin-ligase enzyme (E3) and substrate. Nevertheless, the comprehensive study regarding the role of E2 enzymes in plants remains unexplored. In this review, the ubiquitination process and the regulatory role that E2 enzymes play in plants are primarily discussed, with the focus particularly put on E2's regulation of biological functions of the cell.
由于在自然界中处于静止的生活方式，植物经常面临各种恶劣的环境，如各种非生物和生物胁迫，这导致细胞内自由基的积累、细胞损伤、蛋白质变性等，对细胞造成不良影响。在进化过程中，植物形成了由众多复杂的基因调控网络和信号转导途径组成的防御系统，以调节和维持细胞内稳态。其中，泛素-蛋白酶体途径（UPP）是最通用的细胞信号系统，也是调节细胞生理多方面的强大机制，因为它去除了大部分异常和短寿命的肽和蛋白质。在这个系统中，泛素结合酶（E2）在将泛素从泛素激活酶（E1）转运到泛素连接酶（E3）和底物中起着关键作用。然而，E2 酶在植物中的作用的综合研究仍未被探索。在这篇综述中，主要讨论了泛素化过程以及 E2 酶在植物中的调节作用，特别关注 E2 对细胞生物功能的调节。
