Open AccessEnhancing the copy number of episomal plasmids in S accharomyces cerevisiae for improved protein production
Author(s) -
Chen Yun,
Partow Siavash,
Scalcinati Gionata,
Siewers Verena,
Nielsen Jens
Publication year - 2012
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2012.00809.x
Subject(s) - biology , ura3 , plasmid , microbiology and biotechnology , saccharomyces cerevisiae , lac operon , gene , expression vector , target protein , recombinant dna , biochemistry
2 μm‐based episomal expression vectors are widely used in S accharomyces cerevisiae for recombinant protein production and synthetic pathway optimization. In this study, we report a new approach to increase the plasmid copy number ( PCN ) and thus improve the expression of plasmid‐encoded proteins. This was achieved by combining destabilization of the marker protein with decreasing the marker gene transcription level. Destabilization of the marker protein alone by fusing a ubiquitin/ N ‐degron tag (ubi‐tag) to the N ‐terminus of the U ra3 marker protein could increase the PCN and activity of LacZ expressed from the same vector. When arginine was exposed at the N ‐terminus of the marker protein after cleavage of ubiquitin, the PCN and LacZ activity were increased by 70–80%. Replacement of the native URA3 promoter with the HXT1 , KEX2 or URA3 ‐ d promoter resulted in an increase in the PCN and LacZ activity by about 30–100%. Combining the ubi‐tag and promoter modification of the marker gene, increased the PCN and LacZ activity by threefold. We also demonstrated that this new expression vectors can be used to increase enzyme activity by improving patchoulol production by threefold.