Regulation of SCFTIR1/AFBs E3 ligase assembly by S-nitrosylation of Arabidopsis SKP1-like1 impacts on auxin signaling

The F-box proteins (FBPs) TIR1/AFBs are the substrate recognition subunits of SKP1–cullin–F-box (SCF) ubiquitin ligase complexes and together with Aux/IAAs form the auxin co-receptor. Although tremendous knowledge on auxin perception and signaling has been gained in the last years, SCF complex assem...

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Detalles Bibliográficos
Autores: Iglesias, María José, Marina, Anabel, Casalongué, Claudia
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/181698
Acceso en línea:http://hdl.handle.net/10261/181698
Access Level:acceso abierto
Palabra clave:Nitric oxide
SCF E3 ligase complex
Arabidopsis thaliana
ASK1
Auxin signaling
Descripción
Sumario:The F-box proteins (FBPs) TIR1/AFBs are the substrate recognition subunits of SKP1–cullin–F-box (SCF) ubiquitin ligase complexes and together with Aux/IAAs form the auxin co-receptor. Although tremendous knowledge on auxin perception and signaling has been gained in the last years, SCF complex assembly and stabilization are emerging as new layers of regulation. Here, we investigated how nitric oxide (NO), through S-nitrosylation of ASK1 is involved in SCF assembly. We demonstrate that ASK1 is S-nitrosylated and S-glutathionylated in cysteine (Cys) 37 and Cys118 residues in vitro. Both, in vitro and in vivo protein-protein interaction assays show that NO enhances ASK1 binding to CUL1 and TIR1/AFB2, required for SCF assembly. In addition, we demonstrate that Cys37 and Cys118 are essential residues for proper activation of auxin signaling pathway in planta. Phylogenetic analysis revealed that Cys37 residue is only conserved in SKP proteins in Angiosperms, suggesting that S-nitrosylation on Cys37 could represent an evolutionary adaption for SKP1 function in flowering plants. Collectively, these findings indicate that multiple events of redox modifications might be part of a fine-tuning regulation of SCF for proper auxin signal transduction.