Hyung-Taeg Cho, Minsu Lee, Hee-Seung Choi, Kwang-Ho Maeng, Kyeonghoon Lee, Ha-Yeon Lee, Anindya Ganguly, Hoonyoung Park, Chang-Hoi Ho
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引用次数: 0
Abstract
Combinatorial interactions between different regulators diversify and enrich the chance of transcriptional regulation in eukaryotic cells. However, a dose-dependent functional switch of homologous transcriptional repressors has rarely been reported. Here, we show that SHY2, an auxin/indole-3-acetic acid (Aux/IAA) repressor, exhibits a dose-dependent bimodal role in auxin-sensitive root-hair growth and gene transcription in Arabidopsis, whereas other Aux/IAA homologs consistently repress the auxin responses. The co-repressor (TOPLESS [TPL])-binding affinity of a bimodal Aux/IAA was lower than that of a consistently repressing Aux/IAA. The switch of a single amino acid residue in the TPL-binding motif between the bimodal form and the consistently repressing form switched their TPL-binding affinity and transcriptional and biological roles in auxin responses. Based on these data, we propose a model whereby competition between homologous repressors with different co-repressor-binding affinities could generate a bimodal output at the transcriptional and developmental levels.
期刊介绍:
Molecular Plant is dedicated to serving the plant science community by publishing novel and exciting findings with high significance in plant biology. The journal focuses broadly on cellular biology, physiology, biochemistry, molecular biology, genetics, development, plant-microbe interaction, genomics, bioinformatics, and molecular evolution.
Molecular Plant publishes original research articles, reviews, Correspondence, and Spotlights on the most important developments in plant biology.