Dynamics of regulatory protein complexes in a changing environment – using the example of plant glucosinolate biosynthesis
Transcriptional control involves the formation of complexes between a discrete number of transcription factors (TFs) and regulatory proteins and their subsequent interactions with gene regulatory DNA regions to convey signals to RNA Polymerase-II. These signals, in turn, “instruct” RNA Polymerase whether to transcribe genes and to what extent. This proposal aims to understand how the information encoded by DNA is transformed into specific cellular responses and to study the mechanisms that underlie the formation of TF complexes in response to specific intra- or extracellular signals. While studying the assembly and disassembly of regulatory complexes in response to specific signals, we will address the interactions between complex components and reveal mechanisms that explain the ability of TFs to activate specific cellular responses by regulating a selected set of genes.
In contrast to prokaryotes, the regulation of gene transcription in eukaryotes is controlled not only at the level of transcription, but also epigenetically, post-transcriptionally, translationally and post-translationally. However, with the exception of hormone receptors in eukaryotes and a few primary metabolites in yeast, little is known concerning how small molecules can modulate TF activity or TF complex assembly. In this proposal, we will address how the activity of proteins belonging to the MYB–bHLH regulatory complexes is modulated in response to signalling molecules, using the example of particular class of plant secondary metabolites, namely, glucosinolates (GSLs).
Knowledge gained in this project is expected to extend knowledge on the dynamics of regulatory protein–ligand assembly and disassembly in changing extracellular environments, using the example of the GSL biosynthesis pathway. The results will promote the understanding of metabolite signalling in GSL biosynthesis and will contribute to the understanding of how the activity of regulatory proteins can be generally controlled by the metabolic products. The project will generate insight into the mechanisms by which TFs can activate specific cellular responses in a given environment.