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Physiology of Sacch...
Physiology of Saccharomyces cerevisiae Producing Recombinant Insulin in Continuous Culture
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- Kazemi Seresht, Ali, 1980 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
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(creator_code:org_t)
- ISBN 9789173856423
- 2012
- English.
- Related links:
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https://research.cha...
Abstract
Subject headings
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- The yeast Saccharomyces cerevisiae has widely been used as a host for the production of heterologous proteins. High-level production of heterologous proteins is likely to impose a metabolic burden on the host cell and can thus affect various aspects of cellular physiology. Different target proteins often do not result in similar secretion yields, underlining the dependency of secretion efficiency on the physicochemical properties of the protein of interest. Two human insulin analogue precursors (IAPs) were used as model secretory proteins. The IAPs had minor differences in their amino acid sequences, yet pictured more than 7-fold difference in their secretion yields. Global transcriptome analysis carried out in aerobic glucose-limited chemostat experiments pinpointed distinct steps during the protein maturation pathway to be differentially regulated, and indicated an increased degradation of the IAP with the low secretion yield. The use of auxotrophic strains for improved IAP production was examined. The incremental truncation of the promoter of the auxotrophic marker gene URA3 led to higher plasmid copy numbers, and illustrated that the modification of the level of the recombinant gene dosage via the degree of promoter truncation can be a strong tool for optimizing the IAP productivity. The dynamic character of adaptive responses of S. cerevisiae towards a change in their nutrient access was studied based on global gene expression analysis, scrutinizing the impact of restricted supply of phosphate on the physiological state of IAP-expressing cells. The gradual decrease of the phosphate supply resulted in a step-wise modulated phenotypic response, thereby alternating the specific productivity and the secretory flux. A data-driven approach was applied to study the secretory IAP production in S. cerevisiae in prolonged chemostat cultures (80 generations), with the aim to explore the metabolic adaptation of the cells towards the burden of IAP production. Time-course analysis of global transcriptome and targeted metabolome analysis indicated at metabolic re-modeling of the recombinant cells based on augmented negative selection pressure on glycolytic overcapacity, changes in amino acid and central carbon metabolism, and mitochondrial dysfunction to account for decreased cellular expression efficiency in long-term chemostat cultures.
Subject headings
- NATURVETENSKAP -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)
- NATURVETENSKAP -- Biologi -- Annan biologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences -- Other Biological Topics (hsv//eng)
- NATURVETENSKAP -- Biologi -- Mikrobiologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences -- Microbiology (hsv//eng)
- MEDICIN OCH HÄLSOVETENSKAP -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Basic Medicine -- Microbiology in the medical area (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Industriell bioteknik -- Annan industriell bioteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Industrial Biotechnology -- Other Industrial Biotechnology (hsv//eng)
Keyword
- unfolded protein response
- Keywords: heterologous protein production
- prolonged chemostat
- transcriptome
- insulin analogue precursor
- metabolic adaptation
- URA3d
- plasmid copy number
- promoter truncation
- high cell density cultivation
- TPI1
Publication and Content Type
- dok (subject category)
- vet (subject category)
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