Setting a circadian clock: Structural understanding of the ligand-activation model of the circadian evening complex components ELF4 to ELF3

Lead Research Organisation: University of York
Department Name: Biology


The plant circadian clock drives genome-scale transcription to coordinate most of growth and development. EARLY FLOWERING 3 (ELF3) is the key hub for this diurnal signalling. The Davis group recently showed that ELF3 acts as a receptor integrator for the ELF4 ligand, together termed the Evening Complex, to initiate this foundationally important repressor complex. It was also shown that light represses this action, leading to a hypothesis for the mechanism by which increases in light intensity speed up the clock; light signalling acts as a repressor of a repressor. As ELF3 encodes a protein of unknown activity, it has remained enigmatic how it performs its key repressive role. Here we propose a project to unravel a clock-resetting mechanism by ELF3. Using a combination of biochemical, cellular and structural experiments, one would examine the spatial-temporal function of ELF3. One would monitor the global, genome-wide binding of this chromatin-associated factor to define its transcriptional target genes. Next an exploration of the localisation context of where ELF4 activates ELF3, and how light-perception represses this would be examined. Efforts to solve the co-complex of ELF4 and ELF3 will be undertaken and with associated biophysics of complex assembly, how ELF4 association alters ELF3 folding will be elucidated. As ELF3 is known to be bound and repressed by a photoreceptor, activation of ELF3 by ELF4 will be examined in a testable context that supports "photoreceptor-relief" of this key clock factor. Taken together this project is envisaged to provide one mechanistic basis of a long-standing problem in the clock community termed entrainment, where light perception leads to acceleration of periodicity. This is the first ever description of a clock-resetting mechanism in plants.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M011151/1 30/09/2015 29/09/2023
1792522 Studentship BB/M011151/1 30/09/2016 30/03/2021 James Andrew Ronald
Description BBSRC Whtie Rose Annual Symposium 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Annual meeting of BBSRC whiterose funded PhD students from Leeds, Sheffield and York. Students are invited to speak about their research or placement activity (PIPs) in the form of a presentation and/or a poster.
Year(s) Of Engagement Activity 2017
Description Interactive Research Talks at University Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact As part of the university open day, small informal interactive research talks were held for the visiting students and their parents so that they could learn about the types of research that are carried out at the University of York
Year(s) Of Engagement Activity 2018
Description Interactive School Visit 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact School aged students (GCSE and A-level) came to the University for a one day workshop on the principles of "DNA-fingerprinting" to allow students to understand some of the applications of science, and how science works at a university.
Year(s) Of Engagement Activity 2017