Mechanisms of Gene Regulation
Umemura, Yoshimi , Hiratsu, Keiichiro , Ohme-Takagi, Masaru .
Molecular mechanism of the transcriptional repression mediated by a plant specific transcriptional repression domain, EAR-motif, in Arabidopsis.
We previously reported that the class II ERF transcription factors and a number of TFIIIA-type zinc-finger transcription factors are active repressors in plants. The repression domain of each factors is located in the C-terminal region that contains the conserved ERF-associated Amphiphilic repression (EAR) motif, which is essential for the activity of each repressors. The EAR-motif has been found only in plants. We utilize this EAR-motif for the novel gene silencing system (CRES-T), in which transcriptional activator was converted into a repressor by fusion with the EAR-motif to suppress the expression of the target genes (ref.1). Surprisingly, an amphiphilic motif composed of only 6 amino acids (XLxLXL) is sufficient for strong repression activity (ref.2). However, the mechanism of the repression mediated by the EAR-motif is still unknown. Because of the short peptide, the EAR-motif as itself does not appear to have enzymatic activity. We predict the EAR-motif may interact with other factor(s), such as co-repressor, to repress the transcription. We have isolated the factors that could interact with the EAR-motif using Yeast two-hybrid system. In this report we discuss the possible function of the factors and the mechanism of the EAR motif-dependent transcriptional repression.
1) Hiratsu et al. (2003) Plant J. 34, 733-739
Dominant repression of target genes by chimeric repressors that include the EAR motif, a repression domain, in Arabidopsis.
2) Hiratsu et al. (2004) Biochem. Biophys. Res. Commun. 321, 172-178
Identification of the minimal repression domain of SUPERMAN shows that the DLELRL hexapeptide is both necessary and sufficient for repression of transcription in Arabidopsis.
Log in to add this item to your schedule
Gene Regulation Research Group Web Site
1 - National Institute of Advanced Industrial Science and Technology(AIST), Research Institute of Genome-based Biofactory, AIST4, Higashi 1-1-1, Tsukuba, Ibaraki, 305-8562, Japan
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM