Topic
Pichia pastoris
About: Pichia pastoris is a research topic. Over the lifetime, 7937 publications have been published within this topic receiving 162645 citations. The topic is also known as: Komagataella pastoris.
Papers published on a yearly basis
Papers
More filters
TL;DR: A role for Sap4 to Sap6 in pathogenicity is supported, as a high production of Sap4, Sap5 and Sap6 by C. albicans cells after phagocytosis by murine peritoneal macrophages is demonstrated.
Abstract: Medically important yeasts of the genus Candida secrete aspartyl proteinases (Sap), which are of particular interest as virulence factors. Six closely related gene sequences, SAP1 to SAP6, for secreted proteinases are present in Candida albicans. The methylotrophic yeast Pichia pastoris was chosen as an expression system for preparing substantial amounts of each Sap isoenzyme. Interestingly, Sap4, Sap5 and Sap6, which have not yet been detected in C. albicans cultures in vitro, were produced as active recombinant enzymes. Different Sap polyclonal antibodies were raised in rabbits and tested before further application by enzyme-linked immunosorbent assay (ELISA) against each recombinant Sap. Two antisera recognized only Sap4 to Sap6. Using these antisera, together with sap null mutants obtained by targeted mutagenesis, we could demonstrate a high production of Sap4, Sap5 and Sap6 by C. albicans cells after phagocytosis by murine peritoneal macrophages. Furthermore, a delta sap4,5,6 null mutant was killed 53% more effectively after contact with macrophages than the wild-type strain. These results support a role for Sap4 to Sap6 in pathogenicity.
182 citations
TL;DR: Several new properties of this molecule are reported which show that it is the peroxisomal PTS1 receptor, and the tetratricopeptide repeat (TPR) domain of PAS8p is identified as the PTS1 binding region.
Abstract: The peroxisomal targeting signal 1 (PTS1), consisting of a C-terminal tripeptide (SKL and variants), directs polypeptides to the peroxisome matrix in evolutionarily diverse organisms. Previous studies in the methylotrophic yeast Pichia pastoris identified a 68 kDa protein, PAS8p, as a potential component of the PTS1 import machinery. We now report several new properties of this molecule which, taken together, show that it is the peroxisomal PTS1 receptor. (i) PAS8p is localized to and tightly associated with the cytoplasmic side of the peroxisomal membrane, (ii) peroxisomes of wild-type, but not of pas8 delta (null) mutant, P.pastoris cells bind a PTS1-containing peptide (CRYHLKPLQSKL), (iii) CRYHLKPLQSKL can be cross-linked to PAS8p after binding at the peroxisome membrane and (iv) purified PAS8p binds CRYHLKPLQSKL with high affinity (nanomolar dissociation constant). In addition, the tetratricopeptide repeat (TPR) domain of PAS8p is identified as the PTS1 binding region.
181 citations
TL;DR: It can be concluded that methanol metabolism along with cell lysis towards the end of fermentation contributes to increased proteolytic activity and eventual degradation of recombinant protein.
Abstract: It was observed that during fermentative production of recombinant ovine interferon-tau (r-oIFN-tau) in Pichia pastoris, a secreted recombinant protein, the protein was degraded increasingly after 48 h of induction and the rate of degradation increased towards the end of fermentation at 72 h, when the fermentation was stopped. Proteases, whose primary source was the vacuoles, was found in increasing levels in the cytoplasm and in the fermentation broth after 48 h of induction and reached maximal values when the batch was completed at 72 h. Protease levels at various cell fractions as well as in the culture supernatant were lower when glycerol was used as the carbon source instead of methanol. It can be concluded that methanol metabolism along with cell lysis towards the end of fermentation contributes to increased proteolytic activity and eventual degradation of recombinant protein.
179 citations
TL;DR: The cloning of SnTox3 provides a fundamental tool for the investigation of the S. nodorum–wheat interaction, as well as vital information for the general characterization of necrotroph–plant interactions.
Abstract: The necrotrophic fungus Stagonospora nodorum produces multiple proteinaceous host-selective toxins (HSTs) which act in effector triggered susceptibility. Here, we report the molecular cloning and functional characterization of the SnTox3-encoding gene, designated SnTox3, as well as the initial characterization of the SnTox3 protein. SnTox3 is a 693 bp intron-free gene with little obvious homology to other known genes. The predicted immature SnTox3 protein is 25.8 kDa in size. A 20 amino acid signal sequence as well as a possible pro sequence are predicted. Six cysteine residues are predicted to form disulfide bonds and are shown to be important for SnTox3 activity. Using heterologous expression in Pichia pastoris and transformation into an avirulent S. nodorum isolate, we show that SnTox3 encodes the SnTox3 protein and that SnTox3 interacts with the wheat susceptibility gene Snn3. In addition, the avirulent S. nodorum isolate transformed with SnTox3 was virulent on host lines expressing the Snn3 gene. SnTox3-disrupted mutants were deficient in the production of SnTox3 and avirulent on the Snn3 differential wheat line BG220. An analysis of genetic diversity revealed that SnTox3 is present in 60.1% of a worldwide collection of 923 isolates and occurs as eleven nucleotide haplotypes resulting in four amino acid haplotypes. The cloning of SnTox3 provides a fundamental tool for the investigation of the S. nodorum–wheat interaction, as well as vital information for the general characterization of necrotroph–plant interactions.
179 citations
TL;DR: Overall, the number of GPCR targets that can be produced in the authors' laboratories in sufficient amounts for structural studies has more than doubled, and a general approach for increasing yields of functional mammalian GPCRs severalfold over standard expression conditions is suggested.
Abstract: We have optimized the expression level of 20 mammalian G protein-coupled receptors (GPCRs) in the methylotrophic yeast Pichia pastoris We found that altering expression parameters, including growth temperature, and supplementation of the culture medium with specific GPCR ligands, histidine, and DMSO increased the amount of functional receptor, as assessed by ligand binding, by more than eightfold over standard expression conditions Unexpectedly, we found that the overall amount of GPCR proteins expressed, in most cases, varied only marginally between standard and optimized expression conditions Accordingly, the optimized expression conditions resulted in a marked fractional increase in the ratio of ligand binding-competent receptor to total expressed receptor The results of this study suggest a general approach for increasing yields of functional mammalian GPCRs severalfold over standard expression conditions by using a set of optimized expression condition parameters that we have characterized for the Pichia expression system Overall, we have more than doubled the number of GPCR targets that can be produced in our laboratories in sufficient amounts for structural studies
178 citations