Gene regulation: Expression feels two pulses.

Abstract

Single-cell analyses reveal that combinatorial changes in the intracellular locations of transcription factors can tune the expression of the factors' target genes in response to environmental stimuli. See Article p.54 Many gene-regulatory proteins have been shown to be activated in pulses, but whether cells exploit the relative timing of pulses for different transcription factors has remained unexplored. Now Michael Elowitz and colleagues use single-cell videos to show that yeast cells modulate the relative timing between the pulsatile transcription factors Msn2 and Mig1 — a gene activator and a repressor, respectively — to control the expression of target genes in response to diverse environmental conditions. They also demonstrate that yeast cells respond to various concentrations of glucose by actively modulating the fraction of overlapping Msn2 and Mig1 pulses and regulate target gene expression accordingly.