Jez Joseph M
Department of Biology, Washington University in St. Louis, St. Louis, MO 63130 USA.
Curr Opin Plant Biol. 2022 Apr;66:102194. doi: 10.1016/j.pbi.2022.102194. Epub 2022 Feb 23.
GRETCHEN HAGEN 3 (GH3) acyl acid amido synthetases catalyze the ATP-dependent conjugation of phytohormones with amino acids. Traditionally, GH3 proteins are associated with synthesis of the bioactive jasmonate hormone (+)-7- iso -jasmonoyl-l-isoleucine (JA-Ile) and conjugation of indole-3-acetic acid (IAA) with amino acids that tag the hormone for degradation and/or storage. Modifications of JA and IAA by GH3 acyl acid amido synthetases help maintain phytohormones homeostasis. Recent studies broaden the roles of GH3 proteins to include the regulation of JA biosynthesis; the modification of other auxins (i.e., phenylacetic acid and indole-3-butyric acid); the conjugation of auxinic herbicides, such as 4-dichlorophenoxyacetic acid, 4-(2,4-dichlorophenoxy)butyric acid, and dicamba; and the missing step in the isochorismate pathway for the biosynthesis of salicylic acid. The GH3 protein family joins the growing number of versatile enzyme families that blur the line between primary and specialized metabolism for an increasing range of biology functions.
格雷琴·哈根3（GH3）酰基酸酰胺合成酶催化植物激素与氨基酸的ATP依赖性缀合。传统上，GH3蛋白与生物活性茉莉酸激素（+）-7-异茉莉酰-L-异亮氨酸（JA-Ile）的合成以及吲哚-3-乙酸（IAA）与标记该激素以便降解和/或储存的氨基酸的缀合有关。GH3酰基酸酰胺合成酶对JA和IAA的修饰有助于维持植物激素的稳态。最近的研究拓宽了GH3蛋白的作用，包括对JA生物合成的调节；对其他生长素（即苯乙酸和吲哚-3-丁酸）的修饰；对生长素类除草剂（如2,4-二氯苯氧乙酸、4-（2,4-二氯苯氧基）丁酸和麦草畏）的缀合；以及水杨酸生物合成异分支酸途径中缺失的步骤。GH3蛋白家族加入了越来越多的多功能酶家族行列，这些家族在越来越多的生物学功能中模糊了初级代谢和特殊代谢之间的界限。
