Plant NAC-type transcription factor proteins contain a NARD domain for repression of transcriptional activation

Abstract

Plant-specific transcription factor NAC proteins play essential roles in many biological processes such as development, senescence, morphogenesis, and stress signal transduction pathways. In the NAC family, some members function as transcription activators while others act as repressors. In the present study we found that though the full-length GmNAC20 from soybean did not have transcriptional activation activity, the carboxy-terminal activation domain of GmNAC20 had high transcriptional activation activity in the yeast assay system. Deletion experiments revealed an active repression domain with 35 amino acids, named NARD (NAC Repression Domain), in the d subdomain of NAC DNA-binding domain. NARD can reduce the transcriptional activation ability of diverse transcription factors when fused to either the amino-terminal or the carboxy-terminal of the transcription factors. NARD-like sequences are also present in other NAC family members and they are functional repression domain when fused to VP16 in plant protoplast assay system. Mutation analysis of conserved amino acid residues in NARD showed that the hydrophobic LVFY motif may partially contribute to the repression function. It is hypothesized that the interactions between the repression domain NARD and the carboxy-terminal activation domain may finally determine the ability of NAC family proteins to regulate downstream gene expressions.

Banana Transcription Factor MaERF11 Recruits Histone Deacetylase MaHDA1 and Represses the Expression of MaACO1 and Expansins during Fruit Ripening

“…The first method was performed in tobacco BY2 protoplasts according to Hao et al (2010). Briefly, the coding sequence of MaERF11 without the stop codon was inserted into with pBD-VP16 driven by the 35S promoter plus the translation enhancer V sequence as effector.…”

TheArabidopsisNAC Transcription Factor VNI2 Integrates Abscisic Acid Signals into Leaf Senescence via theCOR/RDGenes

“…A number of transcription factors act either as transcriptional repressors or activators, depending on cellular environments (Ikeda et al, 2009;Hao et al, 2010), indicating that one transcription factor can play multiple roles. The Arabidopsis WUSCHEL transcription factor possesses both transcriptional activation and repression domains.…”

“…Notably, several NAC transcription factors also contain both transcriptional activation and repression domains (Hao et al, 2010). Most of the NAC transcription factors characterized so far are transcriptional activators.…”

“…However, a few NAC transcription factors contain NAC repression domains consisting of ;35 residues within the NAC domains. Consequently, combinatorial effects of both transcriptional regulation activities determine downstream events (Hao et al, 2010).…”

Signaling linkage between environmental stress resistance and leaf senescence inArabidopsis

“…18 Modulation of transcriptional regulation activity is also an intriguing mechanism regulating transcription factor activity. 19,20 The VNI2 transcription factor has been previously reported as a transcriptional repressor. 21 We also found that VNI2 acts as a transcriptional repressor under normal growth conditions.…”