Developmental control of stress stimulons in Streptomyces coelicolor revealed by statistical analyses of global gene expression patterns

Stress-induced regulatory networks coordinated with a procaryotic developme ntal program were revealed by two-dimensional gel analyses of global gene e xpression. Four developmental stages were identified by their distinctive p rotein synthesis patterns using principal component analysis, Statistical a nalyses focused on five stress stimulons (induced by heat, cold, salt, etha nol, or antibiotic shock) and their synthesis during development. Unlike ot her bacteria, for which various stresses induce expression of similar sets of protein spots, in Streptomyces coelicolor heat, salt, and ethanol stimul ons were composed of independent sets of proteins. This suggested independe nt control by different physiological stress signals and their correspondin g regulatory systems. These stress proteins were also under developmental c ontrol. Cluster analysis of stress protein synthesis profiles identified 10 different developmental patterns or "synexpression groups." Proteins induc ed by cold, heat, or salt shock were enriched in three developmental synexp ression groups. In addition, certain proteins belonging to the heat and sal t shock stimulons were coregulated during development, Thus, stress regulat ory systems controlling these stimulons were implicated as integral parts o f the developmental program. This correlation suggested that thermal shock and salt shock stress response regulatory systems either allow the cell to adapt to stresses associated with development or directly control the devel opmental program.