Increasing intracellular magnesium levels with the 31-amino acid MgtS protein.

Synthesis of the 31-amino acid, inner membrane protein MgtS (formerly denoted YneM) is induced by very low Mg2+ in a PhoPQ-dependent manner in Escherichia coli Here we report that MgtS acts to increase intracellular Mg2+ levels and maintain cell integrity upon Mg2+ depletion. Upon development of a functional tagged derivative of MgtS, we found that MgtS interacts with MgtA to increase the levels of this P-type ATPase Mg2+ transporter under Mg2+-limiting conditions. Correspondingly, the effects of MgtS upon Mg2+ limitation are lost in a ∆mgtA mutant, and MgtA overexpression can suppress the ∆mgtS phenotype. MgtS stabilization of MgtA provides an additional layer of regulation of this tightly controlled Mg2+ transporter and adds to the list of small proteins that regulate inner membrane transporters.

Citation

Hanbo Wang, Xuefeng Yin, Mona Wu Orr, Michael Dambach, Rebecca Curtis, Gisela Storz. Increasing intracellular magnesium levels with the 31-amino acid MgtS protein. Proceedings of the National Academy of Sciences of the United States of America. 2017 May 30;114(22):5689-5694

PMID: 28512220

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