Gene Regulation via the Combination of Transcription Factors in the INDETERMINATE DOMAIN and GRAS Families.

Atsushi Kobayashi,Takuya Aoyanagi,Shun Ikeya,Akiko Kozaki

doi:10.3390/genes11060613

Abstract

INDETERMINATE DOMAIN (IDD) family proteins are plant-specific transcription factors. Some Arabidopsis IDD (AtIDD) proteins regulate the expression of SCARECROW (SCR) by interacting with GRAS family transcription factors SHORT-ROOT (SHR) and SCR, which are involved in root tissue formation. Some AtIDD proteins regulate genes involved in the synthesis (GA3ox1) or signaling (SCL3) of gibberellic acid (GA) by interacting with DELLA proteins, a subfamily of the GRAS family. We analyzed the DNA binding properties and protein–protein interactions of select AtIDD proteins. We also investigated the transcriptional activity of the combination of AtIDD and GRAS proteins (AtIDD proteins combined with SHR and SCR or with REPRESSOR of ga1-3 (RGA)) on the promoters of SCR, SCL3, and GA3ox1 by conducting a transient assay using Arabidopsis culture cells. Our results showed that the SCR promoter could be activated by the IDD and RGA complexes and that the SCL3 and GA3ox1 promoters could be activated by the IDD, SHR, and SCR complexes, indicating the possibility that these complexes regulate and consequently coordinate the expression of genes involved in GA synthesis (GA3ox1), GA signaling (SCL3), and root formation (SCR).

Highlights

Transcription factors (TFs) mediate cellular responses by recognizing specific sequences at the promoters of their target genes
Colasanti et al (2006) [3] have classified the INDETERMINATE DOMAIN (IDD) family proteins of Arabidopsis into four groups based on phylogenetic evidence: group A (AtIDD14, 15, and 16), group B (AtIDD1 and 2), group C
We examined whether SCARECROW-LIKE 3 (SCL3) repressed the activity of other IDD protein complexes with REPRESSOR of ga1-3 (RGA) or SHR + SCR on promoters other than SCL3

Summary

Introduction

Transcription factors (TFs) mediate cellular responses by recognizing specific sequences at the promoters of their target genes. The combination of multiple TFs allows TFs to recognize and regulate a target gene. Many TFs interact with other TFs to form complexes, and one TF can regulate multiple distinct genes by interacting with different partner TFs. the protein–protein interactions required for the complex formation between TFs are important to regulate a wide variety of target genes in an appropriate manner. TFs sometimes form families of structurally related proteins with similar DNA-binding specificities. TFs occasionally interact with common partner TFs or regulators to regulate the same target genes, showing functional redundancy when their expression overlaps [1,2]

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