S-nitrosation of SCF E3 ligase components regulates hormonal signaling in Arabidopsis

ABSTRACT: E3 ubiquitin ligases mediate the last step of the ubiquitination pathwayin the ubiquitin-proteasome system (UPS). By targeting transcriptional regulators for their turnover, E3s play a crucial role in every aspect of plant biology. In plants, SKP1/CULLIN1/F-BOX PROTEIN (SCF)-type E3 ubiquitin ligases are essential for the perception and signaling of several key hormones including auxins and jasmonates (JAs). F-box proteins, TRANSPORT INHIBITOR RESPONSE 1 (TIR1) and CORONATINE INSENSITIVE 1 (COI1) bind directly transcriptional repressors AUX/IAAs and JAZs in an auxin- and JAs-depending manner, respectively, which permits the perception of the hormones and transcriptional activation of signaling pathways. Redox modification of proteins mainly by S-nitrosation of cysteines via nitric oxide (NO) has emerged as a valued regulatory mechanism in physiological processes requiring its rapid and versatile integration. Previously, we demonstrated that TIR1 and ASK1 (Arabidopsis thaliana SKP1) are targets of S-nitrosation, and these (NO)-dependent post-translational modifications enhance protein-protein interactions, and positively regulate SCFTIR1 complex assembly and expression of auxin response genes. In this work, we provide evidence on the modulation of SCFCOI1 complex by different S-nitrosation events. We demonstrated that S-nitrosation of ASK1 Cys118 enhanced ASK1-COI1 protein-protein interaction. Overexpression of non-nitrosable ask1 mutant protein impaired the activation of JA-responsive genes mediated by SCFCOI1 illustrating the functional relevance of this redox-mediated regulation in planta. Additionally, in silico analysis positioned COI1 as a promising S-nitrosation target. The regulation of SCF components involved in hormonal perception by S- nitrosation may represent a key strategy to determine the precise time and site-dependent activation of each hormonal signaling pathway, and highlights NO as a pivotal molecular player in these scenarios.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Plant Cell

SUBMITTER: María José Iglesias  

LAB HEAD: María José Iglesias

PROVIDER: PXD030054 | Pride | 2022-04-04

REPOSITORIES: Pride