Correction: Transcriptomic profiling of the yeast Komagataella phaffii in response to environmental alkalinization.
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ABSTRACT:
SUBMITTER: Albacar M
PROVIDER: S-EPMC10576357 | biostudies-literature | 2023 Oct
REPOSITORIES: biostudies-literature
Publications
Correction: Transcriptomic profiling of the yeast Komagataella phaffii in response to environmental alkalinization.
Albacar Marcel M Zekhnini Abdelghani A Pérez-Valle Jorge J Martínez José L JL Casamayor Antonio A Ariño Joaquín J
Microbial cell factories 20231014 1
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Project description:BackgroundAdaptation to alkalinization of the medium in fungi involves an extensive remodeling of gene expression. Komagataella phaffii is an ascomycetous yeast that has become an organism widely used for heterologous protein expression. We explore here the transcriptional impact of moderate alkalinization in this yeast, in search of suitable novel promoters able to drive transcription in response to the pH signal.ResultsIn spite of a minor effect on growth, shifting the cultures from pH 5.5 to 8.0 or 8.2 provokes significant changes in the mRNA levels of over 700 genes. Functional categories such as arginine and methionine biosynthesis, non-reductive iron uptake and phosphate metabolism are enriched in induced genes, whereas many genes encoding iron-sulfur proteins or members of the respirasome were repressed. We also show that alkalinization is accompanied by oxidative stress and we propose this circumstance as a common trigger of a subset of the observed changes. PHO89, encoding a Na+/Pi cotransporter, appears among the most potently induced genes by high pH. We demonstrate that this response is mainly based on two calcineurin-dependent response elements located in its promoter, thus indicating that alkalinization triggers a calcium-mediated signal in K. phaffii.ConclusionsThis work defines in K. phaffii a subset of genes and diverse cellular pathways that are altered in response to moderate alkalinization of the medium, thus setting the basis for developing novel pH-controlled systems for heterologous protein expression in this fungus.
| S-EPMC10071690 | biostudies-literature
Project description:Adaptation to alkalinization of the medium in fungi involves an extensive remodeling of gene expression. Komagataella phaffii is an ascomycetous yeast that has become an organism widely used for heterologous protein expression. We explore here the transcriptional impact of moderate alkalinization in this yeast. In spite of a minor effect on growth, shifting the cultures from pH 5.5 to 8.0 or 8.2 provokes significant changes in the mRNA levels of over 700 genes. Functional categories such as arginine and methionine biosynthesis, non-reductive iron uptake and phosphate metabolism are enriched in induced genes, whereas many genes encoding iron-sulfur proteins or members of the respirasome were repressed. We also show that alkalinization is accompanied by oxidative stress and we propose this circumstance as a common trigger of a subset of the observed changes. PHO89, encoding a Na+/Pi cotransporter, appears among the most potently induced genes by high pH. We demonstrate that this response is mainly based on two calcineurin-dependent response elements located in its promoter, thus indicating that alkalinization triggers a calcium-mediated signal in K. phaffii. Further characterization of alkaline pH responsive promoters may lead to developing novel pH-controlled systems for heterologous protein expression in this fungus.
2023-04-12 | GSE224427 | GEO
Project description:Transcriptomic profiling of the yeast Komagataella phaffii in response to environmental alkalinization
| PRJNA931229 | ENA
Project description:The compartmentalization of metabolic and regulatory pathways is a common pattern of living organisms. Eukaryotic cells are subdivided into several organelles enclosed by lipid membranes. Organelle proteomes define their functions. Yeasts, as simple eukaryotic single cell organisms, are valuable models for higher eukaryotes and frequently used for biotechnological applications. While the subcellular distribution of proteins is well studied in Saccharomyces cerevisiae, this is not the case for other yeasts like Komagataella phaffii (syn. Pichia pastoris). Different to most well-studied yeasts, K. phaffii can grow on methanol, which provides specific features for production of heterologous proteins and as a model for peroxisome biology. We isolated microsomes, very early Golgi, early Golgi, plasma membrane, vacuole, cytosol, peroxisomes and mitochondria of K. phaffii from glucose- and methanol-grown cultures, quantified their proteomes by liquid chromatography-electrospray ionization-mass spectrometry of either unlabeled or tandem mass tag-labeled samples. Classification of the proteins by their relative enrichment, allowed the separation of enriched proteins from potential contaminants in all cellular compartments except the peroxisomes. We discuss differences to S. cerevisiae, outline organelle specific findings and the major metabolic pathways and provide an interactive map of the subcellular localization of proteins in K. phaffii.
| S-EPMC6981350 | biostudies-literature
Project description:In the industrially relevant yeast Komagataella phaffii, as in other yeasts, alkalinization of the medium results in fast and extensive transcriptional remodeling. This response has been useful to design novel methanol-free, regulatable platforms for heterologous protein expression. However, its molecular bases are fully unknown. Crz1 and Rim101/PacC are transcription factors known to contribute to the alkaline pH transcriptional responses in many fungi. We identified here the transcription factors Crz1 and Rim101 in K. phaffii and used CRISPR/Cas9 techniques to create single and double mutant strains. Phenotypic characterization shows that crz1 cells are strongly sensitive to Ca2+ ions, mildly sensitive to alkaline pH and hypertolerant to SDS. In contrast, rim101 cells are markedly hypersensitive to Na+ and Li+ ions, to alkaline pH and to SDS. RNA-seq transcriptomic analysis revealed that mutation of RIM101 affects 55% of genes whose expression is altered at pH 8.0, whereas lack of Crz1 alters only 11% of these. Thirty-eight genes are co-regulated by both Crz1 and Rim101. The PMC1 vacuolar Ca+2-ATPase is regulated by Crz1, whereas the ENA2 Na+-ATPase, the PHO89 and PHO84 phosphate transporters, and diverse genes involved in iron homeostasis are Rim101-dependent. These effects were confirmed by proteomic analyses after 3 h of alkalinization. Therefore, while Rim101 appears as a major player in the transcriptional response to alkalinization, nearly 40% of the alkaline pH transcriptional response in K. phaffii is controlled still unknown pathways.
2025-09-02 | GSE297128 | GEO
Project description:The yeast Komagataella phaffii has become a popular host strain among biotechnology start-up companies for producing recombinant proteins for food and adult nutrition applications. Komagataella phaffii is a host of choice due to its long history of safe use, open access to protocols and strains, a secretome free of host proteins and proteases, and contract manufacturing organizations with deep knowledge in bioprocess scale-up. However, a recent publication highlighted the abundance of an unknown polysaccharide that accumulates in the supernatant during fermentation. This poses a significant challenge in using K. phaffii as a production host. This polysaccharide leads to difficulties in achieving high purity products and requires specialized and costly downstream processing steps for removal. In this study, we describe the use of the common K. phaffii host strain YB-4290 for production of the bioactive milk protein lactoferrin. Upon purification of lactoferrin using membrane-based separation methods, significant amounts of carbohydrate were copurified with the protein. It was determined that the carbohydrate is mostly composed of mannose residues with minor amounts of glucose and glucosamine. The polysaccharide fraction has an average molecular weight of 50 kDa and consists mainly of mannan, galactomannan, and amylose. In addition, a large fraction of the carbohydrate has an unknown structure likely composed of oligosaccharides. Additional strains were tested in fermentation to further understand the source of the carbohydrates. The commonly used industrial hosts, BG10 and YB-4290, produce a basal level of exopolysaccharide; YB-4290 producing slightly more than BG10. Overexpression of recombinant protein stimulates exopolysaccharide production well above levels produced by the host strains alone. Overall, this study aims to provide a foundation for developing methods to improve the economics of recombinant protein production using K. phaffii as a production host.One-sentence summaryOverexpression of recombinant protein stimulates the hyperproduction of high-molecular-weight, mannose-based, exopolysaccharides by the industrial yeast Komagataella phaffii.
| S-EPMC11630240 | biostudies-literature
Project description:Centromere organization has evolved dramatically in one clade of fungi, the Saccharomycotina. These yeasts have lost the ability to make normal eukaryotic heterochromatin with histone H3K9 methylation, which is a major component of pericentromeric regions in other eukaryotes. Following this loss, several different types of centromere emerged, including two types of sequence-defined ("point") centromeres, and the epigenetically defined "small regional" centromeres of Candida albicans Here we report that centromeres of the methylotrophic yeast Komagataella phaffii (formerly called Pichia pastoris) are structurally defined. Each of its four centromeres consists of a 2-kb inverted repeat (IR) flanking a 1-kb central core (mid) region. The four centromeres are unrelated in sequence. CenH3 (Cse4) binds strongly to the cores, with a decreasing gradient along the IRs. This mode of organization resembles Schizosaccharomyces pombe centromeres but is much more compact and lacks the extensive flanking heterochromatic otr repeats. Different isolates of K. phaffii show polymorphism for the orientation of the mid regions, due to recombination in the IRs. CEN4 is located within a 138-kb region that changes orientation during mating-type switching, but switching does not induce recombination of centromeric IRs. Our results demonstrate that evolutionary transitions in centromere organization have occurred in multiple yeast clades.
| S-EPMC5010909 | biostudies-literature
Project description:Synthetic autotrophs can serve as chassis strains for bioproduction from CO2 as a feedstock to take measures against the climate crisis. Integration of the Calvin-Benson-Bassham (CBB) cycle into the methylotrophic yeast Komagataella phaffii (Pichia pastoris) enabled it to use CO2 as the sole carbon source. The key enzyme in this cycle is ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) catalyzing the carboxylation step. However, this enzyme is error prone to perform an oxygenation reaction leading to the production of toxic 2-phosphoglycolate. Native autotrophs have evolved different recycling pathways for 2-phosphoglycolate. However, for synthetic autotrophs, no information is available for the existence of such pathways. Deletion of CYB2 in the autotrophic K. phaffii strain led to the accumulation of glycolate, an intermediate in phosphoglycolate salvage pathways, suggesting that such a pathway is enabled by native K. phaffii enzymes. 13C tracer analysis with labeled glycolate indicated that the yeast pathway recycling phosphoglycolate is similar to the plant salvage pathway. This orthogonal yeast pathway may serve as a sensor for RuBisCO oxygenation, and as an engineering target to boost autotrophic growth rates in K. phaffii.
| S-EPMC10791038 | biostudies-literature
Project description:The important industrial protein production host Komagataella phaffii (syn Pichia pastoris) is classified as a non-conventional yeast. But what exactly makes K. phaffii non-conventional? In this review, we set out to address the main differences to the 'conventional' yeast Saccharomyces cerevisiae, but also pinpoint differences to other non-conventional yeasts used in biotechnology. Apart from its methylotrophic lifestyle, K. phaffii is a Crabtree-negative yeast species. But even within the methylotrophs, K. phaffii possesses distinct regulatory features such as glycerol-repression of the methanol-utilization pathway or the lack of nitrate assimilation. Rewiring of the transcriptional networks regulating carbon (and nitrogen) source utilization clearly contributes to our understanding of genetic events occurring during evolution of yeast species. The mechanisms of mating-type switching and the triggers of morphogenic phenotypes represent further examples for how K. phaffii is distinguished from the model yeast S. cerevisiae. With respect to heterologous protein production, K. phaffii features high secretory capacity but secretes only low amounts of endogenous proteins. Different to S. cerevisiae, the Golgi apparatus of K. phaffii is stacked like in mammals. While it is tempting to speculate that Golgi architecture is correlated to the high secretion levels or the different N-glycan structures observed in K. phaffii, there is recent evidence against this. We conclude that K. phaffii is a yeast with unique features that has a lot of potential to explore both fundamental research questions and industrial applications.
| S-EPMC8709784 | biostudies-literature
Project description:In the industrially relevant yeast Komagataella phaffii, as in other yeasts, alkalinization of the medium results in fast and extensive transcriptional remodeling. This response has been useful to design novel methanol-free, regulatable platforms for heterologous protein expression. However, its molecular bases are fully unknown. Crz1 and Rim101/PacC are transcription factors known to contribute to the alkaline pH transcriptional responses in many fungi. We identified here the transcription factors Crz1 and Rim1 in K. phaffii and used CRISPR/Cas9 techniques to create single and double mutant strains. Phenotypic characterization shows that crz1 cells are strongly sensitive to Ca2+ ions, mildly sensitive to alkaline pH and hypertolerant to SDS. In contrast, rim101 cells are markedly hypersensitive to Na+ and Li+ ions, to alkaline pH and to SDS. RNA-seq transcriptomic analysis revealed that mutation of RIM101 affects 55% of genes whose expression is altered at pH 8.0, whereas lack of Crz1 alters only 11% of these. Thirty-eight genes are co-regulated by both Crz1 and Rim101. The PMC1 vacuolar Ca+2-ATPase is regulated by Crz1, whereas the ENA2 Na+-ATPase, the PHO89 and PHO84 phosphate transporters, and diverse genes involved in iron homeostasis are Rim101-dependent. These effects were confirmed by proteomic analyses after 3 h of alkalinization. Therefore, while Rim101 appears as a major player in the transcriptional response to alkalinization, nearly 40% of the alkaline pH transcriptional response in K. phaffii is controlled still unknown pathways.
2025-09-02 | PXD064682 | Pride