Professor Kunihiko Kaneko and Yusuke Himeoka, a doctoral student at the Graduate School of Arts and Sciences, the University of Tokyo, used computer simulation and theoretical biophysics to elucidate the mechanism by which cells enter a dormant state.
This time, the research group constructed a model of normal protein, abnormal protein, and complex protein of both, and conducted a computer simulation of how the cell state changes by changing the external nutrient concentration.As a result, (3) in a nutrient-rich environment, normal proteins proliferate actively without impairing their functions. (XNUMX) When nutrients are depleted, normal proteins gradually form a complex with abnormal proteins.As the inhibition by the abnormal protein progresses, the growth rate drops sharply, stopping the chemical reaction and leading to a dormant state. ③ When the nutrients are further depleted, the cells begin to die. -It was theoretically clarified that these three types of "phases" are exhibited depending on the nutritional status.
In addition, the research group found that when dormant cells were re-nourished, the waiting time for resumption of growth increased in proportion to the square root of the time spent in starvation, and was rich in nutrients. It was shown to be inversely proportional to the maximum growth rate in the environment.It is said that these theoretical values are in good agreement with recent experimental facts.
The model constructed in this study applies not only to microorganisms but also to many organisms, and this result is expected to contribute to the elucidation of the tolerance of organisms to various stresses and drug development in the future.
Paper information:[PHYSICAL REVIEW X] Theory for Transitions Between Exponential and Stationary Phases: Universal Laws for Lag Time
