
大腸菌の細胞分裂部位の時空間的な制御に寄与するMin システムにおいて、細胞の伸長に伴いMinD濃度勾配が徐々に急峻になり、中心部のMinD濃度が低下することが明らかになった。これにより、FtsZリングの適切な位置決めが可能になると考えられる。


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The Min system contributes to the spatiotemporal regulation of division sites in Escherichia coli . The MinD and MinE proteins of this system self-organize into oscillatory waves in the form of concentration gradients. How the intracellular Min protein concentration gradients are coordinated with cell growth to achieve spatiotemporal accuracy of cell division is unknown. Here, we report that the MinD concentration gradient becomes progressively steeper as cells elongate, suggesting that the division inhibitory activity at the midcell also decreases with cell growth. Interestingly, the oscillation period appears relatively stable across different cell lengths. Similar features were found in cells under carbon stress conditions, but the gradient was even steeper, likely favoring division at shorter cell lengths. The length-dependent variation of the concentration gradient was further examined in silico using a reaction-diffusion model, which not only supported the above features, but also revealed a decrease in the midcell concentration as the shape of the gradient becomes steeper in growing cells. This growth-dependent regulation of the midcell concentration of MinD may be coupled with the FtsZ ring formation through the MinD-interacting protein MinC. We found that the variable concentration gradients occur by coordinating the reaction rates of the recruitment of MinD and MinE to the membrane and the recharging of MinD with ATP in the cytoplasm. In conclusion, this work uncovers the plasticity of MinD concentration gradients during interpolar oscillations throughout cell growth, an intrinsic property integrated during cell division.

### Competing Interest Statement

The authors have declared no competing interest.

Growth-dependent concentration gradient of the oscillating Min system in Escherichia coli

大腸菌における振動する-min-システムの成長依存性濃度勾配


大腸菌における振動する Min システムの成長依存性濃度勾配
