Premium
Sl NAC 1, a stress‐related transcription factor, is fine‐tuned on both the transcriptional and the post‐translational level
Author(s) -
Huang Weizao,
Miao Min,
Kud Joanna,
Niu Xiangli,
Ouyang Bo,
Zhang Junhong,
Ye Zhibiao,
Kuhl Joseph C.,
Liu Yongsheng,
Xiao Fangming
Publication year - 2013
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12096
Subject(s) - proteasome , nicotiana benthamiana , transcription factor , biology , protein degradation , downregulation and upregulation , fusion protein , ubiquitin , biochemistry , microbiology and biotechnology , gene , recombinant dna
Summary The plant‐specific NAC ( N AM , A TAF 1,2, C UC 2) transcription factors play significant roles in diverse physiological processes. In this study, we determined the regulation of a stress‐related tomato ( Solanum lycopersicum ) NAC 1 ( Sl NAC 1) transcription factor at both the transcriptional and the post‐translational level. The Sl NAC 1 protein was found to be stable in the presence of proteasome‐specific inhibitor MG 132 or MG 115 and ubiquitinated in plant cells, suggesting that the Sl NAC 1 is subject to the ubiquitin–proteasome system‐mediated degradation. Deletion analysis identified a short segment of 10 amino acids (aa261–270) that was required for ubiquitin–proteasome system‐mediated degradation, among which two leucine residues (L268 and L269) were critical for the protein instability of Sl NAC 1. Fusion of the degron ( Sl NAC 1 191–270 ) containing these 10 amino acids to green fluorescent protein was found to be sufficient to trigger the degradation of the fusion protein. In addition, the Sl NAC 1 gene is strongly upregulated during Pseudomonas infection, while repression of the NAC 1 ortholog in Nicotiana benthamiana resulted in enhanced susceptibility to Pseudomonas bacteria. These results suggest that rapid upregulation of the NAC 1 gene resulting in more protein production is likely one of the strategies plants use to defend themselves against pathogen infection.