DELLA protein functions as a transcriptional activator through the DNA binding of the INDETERMINATE DOMAIN family proteins

• DOI: 10.1073/pnas.1321669111
• Publication Date: 2014-05-13T08:53:58Z
• Authors: Hideki Yoshida; Ko Hirano; Tomomi Sato; Nobutaka Mitsuda; Mika Nomoto; Kenichiro Maeo; Eriko Koketsu; Rie Mitani; Mayuko Kawamura; Sumie Ishiguro; Yasuomi Tada; Masaru Ohme-Takagi; Makoto Matsuoka; Miyako Ueguchi-Ta...
• Keywords: DNA-Binding Proteins; Transcriptional Activation; 0301 basic medicine; 03 medical and health sciences; Arabidopsis Proteins; Gene Expression Regulation, Plant; Two-Hybrid System Techniques; Arabidopsis; Co-Repressor Proteins; DNA Primers; Plant Proteins; Transcription Factors

SignificanceGibberellin (GA)-dependent degradation of DELLA protein, a key negative regulator, is essential for GA action. However, it is unclear how DELLA regulates downstream gene expression. Although possessing strong transactivation activity, DELLA lacks a DNA-binding domain. Therefore, a model has been proposed in which DELLA acts as a transcriptional coactivator with another transcription factor or factors containing a DNA-binding domain. Here, we show that some members of the INDETERMINATE DOMAIN (IDD) protein family are such intermediate proteins. The DELLA/IDD complex up-regulates the expression of the GA-positive regulatorSCARECROW-LIKE 3(SCL3). Meanwhile, SCL3 protein also interacts with IDD proteins to suppress its own expression. We propose that a coregulator exchange system between DELLA (as coactivator) and SCL3 (as corepressor) regulates the expression ofSCL3.