A heat-activated protein expression system for biotechnology

Abstract

The thermosensory diguanylate cyclase (TdcA) enzyme found in the Pseudomonas aeruginosa strain CF39S produces cyclic diguanylate (c-di-GMP) in response to increases in temperature. The application of TdcA in a heat-activated protein expression system was explored as an alternative to conventional induction systems. C-di-GMP-dependent gene expression measurements were conducted to investigate gene expression levels in Pseudomonas species in the presence of TdcA. An E. coli K12 mutant library was also used to investigate temperature-dependent gene expression levels for the development of a heat-activated protein expression system. Results demonstrated the thermostatted activity of TdcA in Pseudomonas species, while multiple molecular determinants were found to contribute to temperature-dependent biofilm formation and c-di-GMP-dependent gene expression levels in E. coli K12 species. Of these determinants, the c-di-GMP specific phosphodiesterase PdeO was identified as a significant contributor. Further investigation into the applicability of heat-activated expression systems would be of great benefit to the biotechnology sector.