Editor’s summary

Bacterial small proteins regulate diverse cellular activities and responses to environmental stimuli. Vellappan et al. identified small proteins induced by Mg²⁺ starvation in Escherichia coli and investigated their mechanisms of induction, subcellular localization, and effects on cell growth. One of these, YoaI, mediated cross-talk between the PhoR-PhoB and EnvZ-OmpR two-component signaling systems, which control cellular responses to phosphate starvation and osmotic stress, respectively. These findings expand the known repertoire of stress-induced small proteins that regulate bacterial adaptive signaling. —Annalisa M. VanHook