State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China.
Department of Food Science and Engineering, Shandong Agriculture and Engineering University, Jinan, 250100, China.
J Integr Plant Biol. 2023 Aug;65(8):1846-1851. doi: 10.1111/jipb.13493. Epub 2023 May 16.
Phytohormone abscisic acid (ABA) plays vital roles in stress tolerance, while long-term overactivation of ABA signaling suppresses plant growth and development. However, the braking mechanism of ABA responses is not clear. Protein tyrosine sulfation catalyzed by tyrosylprotein sulfotransferase (TPST) is a critical post-translational modification. Through genetic screening, we identified a tpst mutant in Arabidopsis that was hypersensitive to ABA. In-depth analysis revealed that TPST could interact with and sulfate SnRK2.2/2.3/2.6, which accelerated their degradation and weakened the ABA signaling. Taken together, these findings uncovered a novel mechanism of desensitizing ABA responses via protein sulfation.
植物激素脱落酸（ABA）在胁迫耐受中发挥着重要作用，而 ABA 信号的长期过度激活会抑制植物的生长和发育。然而，ABA 响应的制动机制尚不清楚。由酪氨酸蛋白硫酸转移酶（TPST）催化的蛋白酪氨酸硫酸化是一种关键的翻译后修饰。通过遗传筛选，我们在拟南芥中鉴定到一个对 ABA 超敏感的 tpst 突变体。深入分析表明，TPST 可以与 SnRK2.2/2.3/2.6 相互作用并使其硫酸化，从而加速它们的降解并减弱 ABA 信号。综上所述，这些发现揭示了通过蛋白硫酸化来脱敏 ABA 响应的新机制。
