Magnesium (Mg²⁺) is the most prevalent divalent intracellular cation. As co-factor in many enzymatic reactions, Mg²⁺ is essential for protein synthesis, energy production, and DNA stability. Disturbances in intracellular Mg²⁺ concentrations, therefore, unequivocally result in delayed cell growth and metabolic defects. To maintain physiological Mg²⁺ levels, all organisms rely on balanced Mg²⁺ influx and efflux via Mg²⁺ channels and transporters. This review compares the structure and the function of prokaryotic Mg²⁺ transporters and their eukaryotic counterparts. In prokaryotes, cellular Mg²⁺ homeostasis is orchestrated via the CorA, MgtA/B, MgtE, and CorB/C Mg²⁺ transporters. For CorA, MgtE, and CorB/C, the motifs that form the selectivity pore are conserved during evolution. These findings suggest that CNNM proteins, the vertebrate orthologues of CorB/C, also have Mg²⁺ transport capacity. Whereas CorA and CorB/C proteins share the gross quaternary structure and functional properties with their respective orthologues, the MgtE channel only shares the selectivity pore with SLC41 Na⁺/Mg²⁺ transporters. In eukaryotes, TRPM6 and TRPM7 Mg²⁺ channels provide an additional Mg²⁺ transport mechanism, consisting of a fusion of channel with a kinase. The unique features these TRP channels allow the integration of hormonal, cellular, and transcriptional regulatory pathways that determine their Mg²⁺ transport capacity. Our review demonstrates that understanding the structure and function of prokaryotic magnesiotropic proteins aids in our basic understanding of Mg²⁺ transport.

镁 (Mg ²⁺ ) 是最普遍的二价细胞内阳离子。作为许多酶促反应的辅助因子，Mg ²⁺对于蛋白质合成、能量产生和 DNA 稳定性至关重要。因此，细胞内 Mg ²⁺浓度的紊乱无疑会导致细胞生长延迟和代谢缺陷。为了维持生理 Mg ²⁺水平，所有生物都依赖于通过 Mg ²⁺通道和转运蛋白平衡的 Mg ²⁺流入和流出。本综述比较了原核 Mg ²⁺转运蛋白及其真核生物对应物的结构和功能。在原核生物中，细胞 Mg ²⁺体内平衡通过 CorA、MgtA/B、MgTE 和 CorB/C Mg ²⁺转运蛋白进行协调。对于 CorA、MgtE 和 CorB/C，形成选择性孔的基序在进化过程中是保守的。这些发现表明，CNNM 蛋白，即 CorB/C 的脊椎动物直系同源物，也具有 Mg ²⁺转运能力。虽然 CorA 和 CorB/C 蛋白与其各自的直系同源物共享总的四级结构和功能特性，但 MgTE 通道仅与 SLC41 Na ⁺ /Mg ²⁺转运蛋白共享选择性孔。在真核生物中，TRPM6 和 TRPM7 Mg ²⁺通道提供额外的 Mg ²⁺运输机制，由通道与激酶的融合组成。这些 TRP 通道的独特功能允许整合决定其 Mg ²⁺转运能力的激素、细胞和转录调节途径。我们的综述表明，了解原核强磁蛋白的结构和功能有助于我们对 Mg ²⁺转运的基本了解。