Karan S, Choudhury D, Dixit A. Enhanced expression of recombinant proteins in Escherichia coli by co-expression with Vibrio parahaemolyticus CsgG, a pore-forming protein of the curli biogenesis pathway.
J Appl Microbiol 2020;
130:1611-1629. [PMID:
33025668 DOI:
10.1111/jam.14886]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/11/2020] [Accepted: 09/30/2020] [Indexed: 11/28/2022]
Abstract
AIM
To test whether engineered nanopores on the outer membrane (OM) of Escherichia coli can increase expression of heterologous proteins by making additional nutrients available to the host.
METHODS AND RESULTS
Outer membrane nanopores were generated by expressing recombinant Vibrio parahaemolyticus CsgG (rVpCsgG), which spontaneously assembles into a pore-forming channel on the OM, allowing spontaneous diffusion of small chemical entities from the exterior. Protein expression was probed using a reporter protein, sfGFP, expressed on a second compatible plasmid. OM pore formation was shown by acquired erythromycin sensitivity in cells transformed with rVpCsgG, influx of propidium iodide as well as by surface localization of recombinant CsgG by immunogold-labeled transmission electron microscopy. Expression of recombinant CsgG showed increased growth and also enhanced expression of sfGFP in minimal medium and is due to both enhanced transcription as well as translation. Similar enhancement of expression was also observed for a number of different proteins of different origin, sizes and nature.
CONCLUSIONS
Our findings clearly demonstrate that engineered nanopores on the OM of E. coli enhance expression of different heterologous proteins in minimal medium.
SIGNIFICANCE AND IMPACT OF THE STUDY
Vibrio parahaemolyticus CsgG β-nanopore mediated co-expression strategy to improve recombinant protein expression is fully compatible with other methods of protein expression enhancement, and therefore can be a useful tool in biotechnology particularly for whole-cell bio-transformations for production of secondary metabolite.
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