We have developed a novel urea-inducible recombinant protein production system by exploiting the Proteus mirabilis urease ureR-ureD promoter region and the ureR AraC-family transcriptional regulator. Experiments using the expression of β-galactosidase and green fluorescent protein (GFP) showed that promoter activity is tightly regulated and that varying the concentration of urea can give up to 100-fold induction. Production of proteins of biopharmaceutical interest has been demonstrated, including human growth hormone (hGH), a single chain antibody fragment (scFv) against interleukin-1β and a potential Neisserial vaccine candidate (BamAENm). Expression levels can be fine-tuned by temperature and different urea concentrations, and can be induced with readily available garden fertilisers and even urine. As urea is an inexpensive, stable inducer, a urea-induced expression system has the potential to considerably reduce the costs of large-scale recombinant protein production.
Bibliographical note© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/).
Funding statement: J.H. was generously funded by an Industrial Biotechnology Catalyst (Innovate UK, BBSRC, EPSRC) (BB/M018261/1) to support the translation, development and commercialisation of innovative Industrial Biotechnology processes, and, by a BBSRC IAA Follow-on-Fund award (BBSRC IAA BB/S506709/1). D.F.B was supported by BBSRC grants BB/M018261/1 and BB/R017689/1. AO was funded by a BBSRC PhD studentship as part of the Midlands Integrative Biosciences Training Partnership (MIBTP).
- Escherichia coli
- Recombinant protein production
- Transcription regulation