Yong I. Kim
|Dept:||chemistry and environmental|
24-hour daily cycle that are responsive to light and darkness. His research to date has focused on pinpointing the activation and inhibition of proteins integral to regulating the circadian clock and on the biochemical mechanisms that reset it. He is interested in examining disruptions such as jet-lag in order to help devise effective treatments. His research on the molecular mechanisms of the circadian clock has been published in top journals such as the Proceedings of the National Academies of Science, Cell, and Science.
The input pathway detects changes in light and dark from the environment, and synchronizes the phase of oscillator with day/night cycles. The central oscillator is encoded by three genes, kaiA, kaiB, and kaiC, whose protein products function together to generate a 24-hour rhythm of KaiC phosphorylation. KaiC has two residues (Ser431, Thr432) that can be phosphorylated and modulation of KaiC’s autokinase and autophosphatase activities generates a 24-hour period phosphorylation and dephosphorylation rhythm. KaiA activates the autophosphorylation of KaiC and KaiB attenuates KaiA’s function, resulting in KaiC dephosphorylation. The 24-hour KaiC phosphorylation rhythm is generated by timely association and dissociation amongst these three Kai proteins. The oscillator transmits the 24-hour KaiC phosphorylation signal to an output pathway resulting in the regulation of a wide variety of rhythmic behaviors including gene expression. Three genes of the output pathway have been