540 / 2019-03-12 08:50:37

ESCRT-I Component VPS23A Affects ABA Signaling by Recognizing ABA Receptors for Endosomal Degradation

ABA receptors,ESCRTs,ubiquitin,endosomal trafficking

全体主题 > Abiotic Stress

Recent discovery ofPYR/PYL/RCAR-type abscisic acid (ABA) receptors has become one ofmost significant
advances in plant science in the past decade. Inmammals, endosomal sorting acts as an important pathway to downregulate different types of receptors, but its role in plant hormone signaling is poorly understood. Here, we report that an ubiquitin E2-like protein, VPS23A, which is a key component of ESCRT-I, negatively regulates ABA signaling. VPS23A has epistatic relationship with PYR/PYL/RCAR-type ABA receptors and disruption of VPS23A enhanced the activity of key kinase OST1 in the ABA signaling pathway under ABA treatment. Moreover, VPS23A interacts with PYR1/PYLs and K63-linked diubiquitin, and PYL4 possesses K63-linked ubiquitinatedmodification in vivo. Further analysis revealed that VPS23A affects the subcellular localization ofPYR1 and the stability ofPYL4.Taken together, our results suggest that VPS23AaffectsPYR1/PYL4 via vacuole-mediated degradation, providing an advanced understanding of both the turnover of ABA receptors and ESCRTs in plant hormone signaling.