Inhibition of AtMYB2 DNA-binding by nitric oxide involves cysteine S-nitrosylation.
Nitric oxide (NO) can influence the transcriptional activity of a wide set of Arabidopsis genes. The aim of the present work was to investigate if NO modifies DNA-binding activity of AtMYB2 (a typical R2R3-MYB from Arabidopsis thaliana), by a posttranslational modification of its conserved Cys53 residue. We cloned a fully active minimal DNA-binding domain of AtMYB2 spanning residues 19-125, hereafter called M2D. In EMSA assays, M2D binds the core binding site 5'-[A]AACC[A]-3'. The NO donors SNP and GSNO inhibit M2D DNA-binding. As expected for a Cys S-nitrosylation, the NO-mediated inhibitory effect was reversed by DTT, and S-nitrosylation of Cys53 in M2D was detected by biotin switch assays. These results demonstrate that the DNA-binding of M2D is inhibited by S-nitrosylation of Cys53 as a consequence of NO action, thus establishing for the first time a relationship between the redox state and DNA-binding in a plant MYB transcription factor.
Serpa
Viviane
V
Laboratório de Expressão Gênica, Departamento de Bioquímica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC, Brazil.
Vernal
Javier
J
Lamattina
Lorenzo
L
Grotewold
Erich
E
Cassia
Raul
R
Terenzi
Hernán
H
D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry*; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry; D009569:Nitric Oxide / Q000737:chemistry*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010084:Oxidation-Reduction; D011499:Protein Processing, Post-Translational; D026422:S-Nitrosoglutathione / Q000494:pharmacology; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C104175:MYB2 protein, Arabidopsis; D020030:Nitric Oxide Donors; D015534:Trans-Activators; D009599:Nitroprusside; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D004247:DNA; D003545:Cysteine