The Need for Speed: Understanding the Importance of Different ELF3 Nuclear Localisation Mechanisms

Circadian clocks are endogenous timekeeping mechanisms that enable organisms to coordinate their internal physiological responses with the external environmental. Manipulation of the plant circadian clock has been critical for plant domestication, while further alterations to clock function will contribute to the generation of crop varieties suitable for the changing climate. Over the last three decades of plant circadian research, we have developed detailed genetic and mathematical models of the clock system. In contrast, studies investigating the protein dynamics of the plant circadian clock are nascent. Where and when circadian proteins are active in the cell remains largely unknown. Understanding the circadian clock from a protein perspective is necessary to fully conceptualise and understand the impact of gene mutations on function and phenotype.
The research proposed in this fellowship will investigate the cellular dynamics of the plant circadian protein EARLY FLOWERING3 (ELF3), a key hub protein within the plant circadian clock. So far, all functions of ELF3 are dependent on its localisation to the nucleus. However, it remains unknown how ELF3 arrives in the nucleus. Originally, ELF3 was proposed to localise to the nucleus through a specific sequence motif. However, this sequence motif is present in only a small number of plant species. Instead, my research suggests that ELF3 localises to the nucleus through interactions with other proteins. Understanding how these protein-protein interactions mediates the nuclear localisation of ELF3 is critical in understanding how ELF3 functions.
The proposed work will utilise cellular, biochemical, and genetic approaches to provide new fundamental insights into how ELF3 localises to the nucleus and the contribution of this mechanism for its overall functionality.