Michael J. Rust, Ph.D.

Research

The goal of my research is to understand how the components of a circadian clock work together to ensure that an organism can monitor and respond to its environment. Many organisms, from bacteria to humans, possess a circadian clock that allows them to synchronize their activities with the time of day. This biological circuit is particularly critical in photosynthetic organisms, which rely on sunlight to produce their food. As a postdoctoral fellow, I showed how the components of a circadian clock isolated from a photosynthetic bacterium could correctly “keep time” in a test tube, with one of the components periodically switching itself on and off over a 24-hour cycle. Now, using a suite of biochemical and biophysical analyses and mathematical modeling, my laboratory will link the molecular properties of clock proteins to the emergence of rhythms at the organismal scale and how they support health and fitness in fluctuating environments, such as seasonal changes in the length of the day. This work will enhance our understanding of biological clocks and could offer clues to coping with the conditions of modern life, including shift work and jet lag, which pose challenges for our own circadian rhythms.

As Innovation Fund investigators, Michael J. Rust, Ph.D., and Suckjoon Jun, Ph.D., are joining forces to explore how cyanobacteria regulate growth and allocate cellular resources in fluctuating environments. Their goal is to uncover fundamental principles of physiological control that go beyond what has been learned from heterotrophic bacteria such as Escherichia coli and may extend to eukaryotic systems. To achieve this, the team will first adapt quantitative growth analysis methods developed in the Jun lab to define growth laws governing cyanobacteria under constant conditions. They will then extend this analysis to cycling light-dark environments and, using circadian clock mutants developed in the Rust lab, determine how internal rhythmicity influences growth rules. Finally, they will employ high-throughput sequencing to identify trade-offs between growth rate maximization and stress tolerance and uncover their mechanistic basis. Together, this work will broaden our understanding of the universal principles underlying cellular growth that extend beyond E. coli to diverse life forms.