Regulation of gene expression by manipulating transcriptional repressor activity using a novel CoSRI technology.

Yue Xu,Song Feng Li,Roger W Parish

doi:10.1111/pbi.12683

Abstract

SummaryTargeted gene manipulation is a central strategy for studying gene function and identifying related biological processes. However, a methodology for manipulating the regulatory motifs of transcription factors is lacking as these factors commonly possess multiple motifs (e.g. repression and activation motifs) which collaborate with each other to regulate multiple biological processes. We describe a novel approach designated conserved sequence‐guided repressor inhibition (CoSRI) that can specifically reduce or abolish the repressive activities of transcription factors in vivo. The technology was evaluated using the chimeric MYB80‐EAR transcription factor and subsequently the endogenous WUS transcription factor. The technology was employed to develop a reversible male sterility system applicable to hybrid seed production. In order to determine the capacity of the technology to regulate the activity of endogenous transcription factors, the WUS repressor was chosen. The WUS repression motif could be inhibited in vivo and the transformed plants exhibited the wus‐1 phenotype. Consequently, the technology can be used to manipulate the activities of transcriptional repressor motifs regulating beneficial traits in crop plants and other eukaryotic organisms.

Highlights

A mechanism of active gene repression shared by all eukaryotes involves the recruitment of co-repressors and chromatin remodelling factors by the repression motifs of transcription factors (Krogan and Long, 2009)
The conserved sequence-guided repressor inhibition (CoSRI) protein consists of the repression motif-interacting region (RMIR) of a corepressor fused with a targeting sequence (TS) derived from the repressor targeted for inhibition (Figure 1a)
The targeting sequence is chosen to be conserved in the orthologues/homologues from different plant species and is likely to interact with other factors present in the repressor complex

Summary

Introduction

A mechanism of active gene repression shared by all eukaryotes involves the recruitment of co-repressors and chromatin remodelling factors (e.g. histone deacetylases) by the repression motifs of transcription factors (Krogan and Long, 2009). The N-terminal domains (amino acids 1–209) of the TPL/TPR co-repressor bind with the repression motifs of the transcription factors and form dimers and tetramers (Ke et al, 2015; Long et al, 2006). The domain organization of TPL/TPR and other co-repressors is similar Examples of such co-repressors include LEUNIG (LUG) from Arabidopsis, Tup and SIF from yeast, Groucho (Gro) from Drosophila and human transducin-like enhancers of split (TLEs) (Chen and Courey, 2000; Liu and Karmarkar, 2008)

Objectives

Results

Discussion

Conclusion