Early Consequences of Thiophosphate Substitution in Escherichia coli: Possible Epigenetic and Energetic Factors

Abstract

Substitution of thiophosphate for phosphate during the culture of Escherichia coli leads to an increase in biosynthetic activity across a broad spectrum of pathways. To investigate the basis for this enhanced profile, early analysis of RNA transcripts was performed using RNA seq methods. The results identified a possible mediator of activation, namely the ser/thr kinase, yegI, which was increased ~190X fold during the first 1 hr. of induction. There is also a massive shift in the amount of non-ribosomal RNA relative to rRNA of 8-10X fold. RNA seq analysis further supports the idea that energy savings from reduced RNA turnover in thiophosphate treated cells, is the driving force for triggering the enhanced transcriptional profile in Escherichia coli. Thus, in response to an increased energy state, the cells appear to activate a new transcriptional program via a protein kinase cascade.