Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale School of Medicine, New Haven, Connecticut 06536; email:
Annu Rev Genet. 2013;47:625-46. doi: 10.1146/annurev-genet-051313-051025. Epub 2013 Sep 20.
Organisms must maintain physiological levels of Mg(2+) because this divalent cation is critical for the stabilization of membranes and ribosomes, for the neutralization of nucleic acids, and as a cofactor in a variety of enzymatic reactions. In this review, we describe the mechanisms that bacteria utilize to sense the levels of Mg(2+) both outside and inside the cytoplasm. We examine how bacteria achieve Mg(2+) homeostasis by adjusting the expression and activity of Mg(2+) transporters and by changing the composition of their cell envelope. We discuss the connections that exist between Mg(2+) sensing, Mg(2+) transport, and bacterial virulence. Additionally, we explore the logic behind the fact that bacterial genomes encode multiple Mg(2+) transporters and distinct sensing systems for cytoplasmic and extracytoplasmic Mg(2+). These analyses may be applicable to the homeostatic control of other cations.
生物体必须维持生理水平的 Mg(2+)，因为这种二价阳离子对于膜和核糖体的稳定、核酸的中和以及各种酶反应的辅助因子都至关重要。在这篇综述中，我们描述了细菌用来感知细胞质内外 Mg(2+)水平的机制。我们研究了细菌如何通过调节 Mg(2+)转运体的表达和活性以及改变其细胞包膜的组成来实现 Mg(2+)的稳态。我们讨论了 Mg(2+)感应、Mg(2+)转运和细菌毒力之间存在的联系。此外，我们还探讨了细菌基因组编码多个 Mg(2+)转运体和细胞质内和细胞外 Mg(2+)的不同感应系统的原因。这些分析可能适用于其他阳离子的稳态控制。
