Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.
Howard Hughes Medical Institute, Yale University, New Haven, CT, USA.
Nat Chem Biol. 2022 Aug;18(8):878-885. doi: 10.1038/s41589-022-01086-4. Epub 2022 Jul 25.
Organisms presumably have mechanisms to monitor and physiologically adapt to changes in cellular Na concentrations. Only a single bacterial protein has previously been demonstrated to selectively sense Na and regulate gene expression. Here we report a riboswitch class, previously called the 'DUF1646 motif', whose members selectively sense Na and regulate the expression of genes relevant to sodium biology. Many proteins encoded by Na-riboswitch-regulated genes are annotated as metal ion transporters, whereas others are involved in mitigating osmotic stress or harnessing Na gradients for ATP production. Na riboswitches exhibit dissociation constants in the low mM range, and strongly reject all other alkali and alkaline earth ions. Likewise, only Na triggers riboswitch-mediated transcription and gene expression changes. These findings reveal that some bacteria use Na riboswitches to monitor, adjust and exploit Na concentrations and gradients, and in some instances collaborate with c-di-AMP riboswitches to coordinate gene expression during osmotic stress.
生物 presumably 有机制来监测和生理上适应细胞 Na 浓度的变化。先前只有一种细菌蛋白被证明可以选择性地感知 Na 并调节基因表达。在这里，我们报告了一类以前称为“DUF1646 基序”的 riboswitch，其成员选择性地感知 Na 并调节与钠生物学相关的基因的表达。由 Na-riboswitch 调控基因编码的许多蛋白质被注释为金属离子转运蛋白，而其他蛋白质则参与减轻渗透胁迫或利用 Na 梯度产生 ATP。Na riboswitches 的解离常数在低 mM 范围内，强烈排斥所有其他碱金属和碱土金属离子。同样，只有 Na 触发 riboswitch 介导的转录和基因表达变化。这些发现表明，一些细菌利用 Na riboswitches 来监测、调整和利用 Na 浓度和梯度，并且在某些情况下与 c-di-AMP riboswitches 合作，在渗透胁迫期间协调基因表达。
