Role of phosphate limitation and pyruvate decarboxylase in rewiring of the metabolic network for increasing flux towards isoprenoid pathway in a TATA binding protein mutant of Saccharomyces cerevisiae
| Autor: | Sumana Srinivasan, Kareenhalli V. Venkatesh, Anand K. Bachhawat, Manisha Wadhwa |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Mutant Saccharomyces cerevisiae lcsh:QR1-502 SULFUR Bioengineering Phosphate Applied Microbiology and Biotechnology Cofactor lcsh:Microbiology Phosphates 03 medical and health sciences DEHYDROGENASE Metabolic flux analysis NADPH YEAST BIOSYNTHESIS PRECURSOR ACETYL-COA biology Chemistry Terpenes organic chemicals Isoprenoid pathway PDC6 Metabolism biology.organism_classification TATA-Box Binding Protein Cytosol PHOSPHORUS 030104 developmental biology Biochemistry Metabolic Engineering Mutation ACID CELLS biology.protein SPT15 MACHINERY lipids (amino acids peptides and proteins) Metabolic flux distribution Flux (metabolism) Pyruvate Decarboxylase Pyruvate decarboxylase Metabolic Networks and Pathways NADP Biotechnology |
| Zdroj: | Microbial Cell Factories, Vol 17, Iss 1, Pp 1-14 (2018) |
| ISSN: | 1475-2859 |
| DOI: | 10.1186/s12934-018-1000-1 |
| Popis: | Background Production of isoprenoids, a large and diverse class of commercially important chemicals, can be achieved through engineering metabolism in microorganisms. Several attempts have been made to reroute metabolic flux towards isoprenoid pathway in yeast. Most approaches have focused on the core isoprenoid pathway as well as on meeting the increased precursors and cofactor requirements. To identify unexplored genetic targets that positively influence the isoprenoid pathway activity, a carotenoid based genetic screen was previously developed and three novel mutants of a global TATA binding protein SPT15 was isolated for heightened isoprenoid flux in Saccharomyces cerevisiae. Results In this study, we investigated how one of the three spt15 mutants, spt15_Ala101Thr, was leading to enhanced isoprenoid pathway flux in S. cerevisiae. Metabolic flux analysis of the spt15_Ala101Thr mutant initially revealed a rerouting of the central carbon metabolism for the production of the precursor acetyl-CoA through activation of pyruvate-acetaldehyde-acetate cycle in the cytoplasm due to high flux in the reaction caused by pyruvate decarboxylase (PDC). This led to alternate routes of cytosolic NADPH generation, increased mitochondrial ATP production and phosphate demand in the mutant strain. Comparison of the transcriptomics of the spt15_Ala101Thr mutant cell with SPT15WT bearing cells shows upregulation of phosphate mobilization genes and pyruvate decarboxylase 6 (PDC6). Increasing the extracellular phosphate led to an increase in the growth rate and biomass but diverted flux away from the isoprenoid pathway. PDC6 is also shown to play a critical role in isoprenoid pathway flux under phosphate limitation conditions. Conclusion The study not only proposes a probable mechanism as to how a spt15_Ala101Thr mutant (a global TATA binding protein mutant) could increase flux towards the isoprenoid pathway, but also PDC as a new route of metabolic manipulation for increasing the isoprenoid flux in yeast. |
| Databáze: | OpenAIRE |
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