Small proteins regulate <i>Salmonella</i> survival inside macrophages by controlling degradation of a magnesium transporter
Jinki Yeom, Yi Shao, Eduardo A. Groisman
Abstract
Significance The murine protein Slc11a1 (SLC11A1 in humans) hinders replication of invading microbes by provoking Mg 2+ limitation in host tissues. To withstand Mg 2+ limitation and to promote survival in Slc11a1 + / + macrophages, the intracellular pathogen Salmonella enterica serovar Typhimurium requires MgtB, one of its three Mg 2+ transporters and the only one absent from commensal Escherichia coli . Although MgtB is 50% identical to the Mg 2+ transporter MgtA, the latter is dispensable for virulence and exhibits different activity and specificity. When Salmonella experiences Mg 2+ limitation, the combined activities of the small proteins MgtR and MgtU result in MgtB stabilization and MgtA proteolysis.