A protein expression during development of S. coelicolor in liquid medium

In this paper we analyzed the S.coelicolor proteome at four points in time as it grew in liquid medium s i using three biological and two technical replicates. The proteome was measured during exponential growth and its entry into the stationary phase at 20, 35, 50 and 65 hours. Differential expression analysis identified key metabolic pathways and their hierarchy of activation during population growth. 4 and 3 pathways were found significantly overrepresented only under 35 to 20 hours or 50 to 35 hours respectively. Six pathways were found to be overrepresented within all three temporal groups (20 to 35 hours, 35 to 50 hours and 50 to 65 hours), with one pathway being significantly overrepresented exclusively in the 50-65 h interval. Central metabolic system enzymes involved in DNA replication were enriched in the late stages while the proteins involved in the transcription and translation machinery were overrepresented in early stages and decreased over time. A strong correlation was found between the expression of about a third of the proteins and mRNA, while another third correlated negatively. The data presented here represents quantitative evidence for the growing populations’ observed behaviour.