Ubiquitin-Mediated Control of Plant Hormone Signaling
Ubiquitin-Mediated Control of Plant Hormone Signaling
复制标题
DOI：
10.1104/pp.112.200527
复制
发表时间：
2012-09-01
期刊：
影响因子：
7.4
通讯作者：
Estelle, Mark
中科院分区：
文献类型：
--
作者：
Kelley, Dior R.;Estelle, Mark
泛素-蛋白酶体系统（UPS）在植物生物学的几乎每个方面都发挥着作用。丰富的新兴数据表明，受管制的蛋白质降解竞争的转录调控领域的重要性，在细胞调控。在本次更新中，我们将重点介绍目前的研究结果，说明UPS对植物激素信号的贡献。我们还将考虑悬而未决的问题，并讨论可能的实验方法，这将增加我们对调节蛋白质降解的理解。UPS活性涉及E1、E2和E3酶之间的三步酶级联反应，导致泛素共价转移至靶蛋白。这一过程可能导致不同的结果，包括（1）26 S蛋白酶体的蛋白水解降解或可逆的非蛋白水解调节事件。目前的植物基因组注释表明，大多数物种可以产生超过1，000种不同的UPS组分; E3连接酶家族蛋白是最丰富的（Du et al.，2009; Vierstra，2009）。因此，UPS的潜在范围是广泛的。E3连接酶通过直接控制泛素向靶底物的转移来提供特异性，并已基于其复杂组成和作用模式分为四组：HECT、RING、U-盒和cullin-RING连接酶（CRL; Vierstra，2009）。CRL是多亚基连接酶，其可以基于可变靶识别模块进一步细分为四类：（1）在S期激酶相关蛋白1-cullin 1-F-box（SCF）连接酶的情况下的F-box蛋白;（2）限定E3的BTB组的bric-a-brac-tramtrak-broad复合物（BTB）蛋白;（3）利用含有WD 40结构域的DWD蛋白的DNA损伤结合（DDB）类;以及（4）后期促进复合物类别，其包含几种可互换的识别蛋白（Vierstra，2009）。总而言之，这些酶模块是令人难以置信的多样性，它们的许多目标是目前未知的。
The ubiquitin-proteasome system (UPS) plays a role in nearly every aspect of plant biology. The wealth of emerging data demonstrates that regulated protein degradation rivals the well-studied area of transcriptional regulation for importance in cellular regulation. In this Update, we will highlight current research findings that illustrate the contributions of the UPS to phytohormone signaling. We will also consider outstanding questions and discuss possible experimental approaches that will increase our understanding of regulated protein degradation. UPS activity involves a three-step enzymatic cascade between E1, E2, and E3 enzymes that results in the covalent transfer of ubiquitin to target proteins. This process can result in different outcomes, including (1) proteolytic degradation by the 26S proteasome or reversible, nonproteolytic regulatory events. Current plant genome annotations indicate that most species can produce over 1,000 different UPS components; E3 ligase family proteins are the most abundant (Du et al., 2009; Vierstra, 2009). Thus, the potential scope of the UPS is extensive. E3 ligases provide specificity by directly controlling the transfer of ubiquitin to the target substrate and have been classified into four groups based on their complex composition and modes of action: HECT, RING, U-box, and cullin-RING ligases (CRLs; Vierstra, 2009). CRLs are multisubunit ligases that can be further subdivided into four groups based on a variable target recognition module:(1) F-box proteins in the case of S-phase kinase-associated protein1-cullin1-F-box (SCF) ligases;(2) bric-a-brac-tramtrak-broad complex (BTB) proteins that define the BTB group of E3s;(3) the DNA damage-binding (DDB) class that utilizes WD40 domain-containing DWD proteins; and (4) the anaphase-promoting complex category that contains several interchangeable recognition proteins (Vierstra, 2009). Altogether, these enzymatic modules are incredibly diverse, and many of their targets are currently unknown.