Beers Eric P, Jones Alan M, Dickerman Allan W
Department of Horticulture, Virginia Polytechnic Institute and State University,Blacksburg, VA, 24061, USA.
Phytochemistry. 2004 Jan;65(1):43-58. doi: 10.1016/j.phytochem.2003.09.005.
The Arabidopsis thaliana genome has over 550 protease sequences representing all five catalytic types: serine, cysteine, aspartic acid, metallo and threonine (MEROPS peptidase database, http://merops.sanger.ac.uk/), which probably reflect a wide variety of as yet unidentified functions performed by plant proteases. Recent indications that the 26S proteasome, a T1 family-threonine protease, is a regulator of light and hormone responsive signal transduction highlight the potential of proteases to participate in many aspects of plant growth and development. Recent discoveries that proteases are required for stomatal distribution, embryo development and disease resistance point to wider roles for four additional multigene families that include some of the most frequently studied (yet poorly understood) plant proteases: the subtilisin-like, serine proteases (family S8), the papain-like, cysteine proteases (family C1A), the pepsin-like, aspartic proteases (family A1) and the plant matrixin, metalloproteases (family M10A). In this report, 54 subtilisin-like, 30 papain-like and 59 pepsin-like proteases from Arabidopsis, are compared with S8, C1A and A1 proteases known from other plant species at the functional, phylogenetic and gene structure levels. Examples of structural conservation between S8, C1A and A1 genes from rice, barley, tomato and soybean and those from Arabidopsis are noted, indicating that some common, essential plant protease roles were established before the divergence of monocots and eudicots. Numerous examples of tandem duplications of protease genes and evidence for a variety of restricted expression patterns suggest that a high degree of specialization exists among proteases within each family. We propose that comprehensive analysis of the functions of these genes in Arabidopsis will firmly establish serine, cysteine and aspartic proteases as regulators and effectors of a wide range of plant processes.
拟南芥基因组中有超过550个蛋白酶序列，代表了所有五种催化类型：丝氨酸、半胱氨酸、天冬氨酸、金属蛋白酶和苏氨酸（《酶类数据库》，http://merops.sanger.ac.uk/），这可能反映了植物蛋白酶执行的多种尚未确定的功能。最近有迹象表明，26S蛋白酶体（一种T1家族 - 苏氨酸蛋白酶）是光和激素响应信号转导的调节因子，这凸显了蛋白酶参与植物生长和发育许多方面的潜力。最近的发现表明，蛋白酶对于气孔分布、胚胎发育和抗病性是必需的，这指出了另外四个多基因家族具有更广泛的作用，其中包括一些研究最频繁（但了解甚少）的植物蛋白酶：枯草杆菌蛋白酶样丝氨酸蛋白酶（S8家族）、木瓜蛋白酶样半胱氨酸蛋白酶（C1A家族）、胃蛋白酶样天冬氨酸蛋白酶（A1家族）和植物基质金属蛋白酶（M10A家族）。在本报告中，将来自拟南芥的54个枯草杆菌蛋白酶样、30个木瓜蛋白酶样和59个胃蛋白酶样蛋白酶，与其他植物物种已知的S8、C1A和A1蛋白酶在功能、系统发育和基因结构水平上进行了比较。注意到水稻、大麦、番茄和大豆以及拟南芥的S8、C1A和A1基因之间存在结构保守的例子，这表明在单子叶植物和双子叶植物分化之前就已经确立了一些常见的、基本的植物蛋白酶作用。蛋白酶基因串联重复的大量例子以及各种受限表达模式的证据表明，每个家族中的蛋白酶之间存在高度的专业化。我们建议，对拟南芥中这些基因功能的全面分析将牢固地确立丝氨酸、半胱氨酸和天冬氨酸蛋白酶作为广泛植物过程的调节因子和效应器。
