Temporal σ stress-response profiles impact fitness.

Unlabelled: The Gram-positive model organism responds to environmental stressors by activating the alternative sigma factor σ. The sensing apparatus upstream of σ activation is thought to consist of cytoplasmic stressosomes-megadalton-sized protein complexes that include five paralogous proteins known as RsbRs. The RsbRs are presumed to be involved in stress sensing and the subsequent response.