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Wu P, Zhou J, Yu Y, Lu H. Characterization of essential elements for improved episomal expressions in
Kluyveromyces marxianus. Biotechnol J 2022; 17:e2100382. [DOI: 10.1002/biot.202100382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 12/16/2021] [Accepted: 01/04/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Pingping Wu
- State Key Laboratory of Genetic Engineering School of Life Sciences Fudan University Shanghai China
- Shanghai Engineering Research Center of Industrial Microorganisms Shanghai China
| | - Jungang Zhou
- State Key Laboratory of Genetic Engineering School of Life Sciences Fudan University Shanghai China
- Shanghai Engineering Research Center of Industrial Microorganisms Shanghai China
| | - Yao Yu
- State Key Laboratory of Genetic Engineering School of Life Sciences Fudan University Shanghai China
- Shanghai Engineering Research Center of Industrial Microorganisms Shanghai China
- National Technology Innovation Center of Synthetic Biology Tianjin China
| | - Hong Lu
- State Key Laboratory of Genetic Engineering School of Life Sciences Fudan University Shanghai China
- Shanghai Engineering Research Center of Industrial Microorganisms Shanghai China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology Shanghai China
- National Technology Innovation Center of Synthetic Biology Tianjin China
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McQuaid ME, Pinder JB, Arumuggam N, Lacoste JSC, Chew JSK, Dobson MJ. The yeast 2-μm plasmid Raf protein contributes to plasmid inheritance by stabilizing the Rep1 and Rep2 partitioning proteins. Nucleic Acids Res 2017; 45:10518-10533. [PMID: 29048592 PMCID: PMC5737570 DOI: 10.1093/nar/gkx703] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 08/01/2017] [Indexed: 12/26/2022] Open
Abstract
The yeast 2-μm plasmid is a remarkable genetic parasite, managing efficient maintenance at high-copy number with minimal impact on the host. Equal partitioning of the plasmid upon host cell division requires plasmid proteins Rep1 and Rep2 and the plasmid STB locus. The Rep proteins and the plasmid-encoded Raf protein also regulate plasmid gene transcription. In this study, protein interaction assays, sequence analyses and mutational approaches were used to identify domains and residues in Rep2 and Raf required for association with Rep1 and Rep2 and to delineate the Rep2 DNA-binding domain. Rep2 and Raf displayed similarities in interactions with Rep1 and Rep2, in having Rep1 promote their STB association in vivo, and in stabilizing Rep protein levels. Rep2 mutants impaired for self-association were competent for transcriptional repression while those deficient for Rep1 association were not. Surprisingly, Rep2 mutants impaired for either Rep1 interaction or self-association were able to maintain efficient plasmid inheritance provided Raf was present and competent for Rep protein interaction. Our findings provide insight into the Rep protein complexes required for partitioning and transcriptional repression, and suggest that in addition to its transcriptional function, Raf stabilization of Rep partitioning proteins contributes to the remarkable persistence of the 2-μm plasmid.
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Affiliation(s)
- Mary E McQuaid
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jordan B Pinder
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Niroshaathevi Arumuggam
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jessica S C Lacoste
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Joyce S K Chew
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Melanie J Dobson
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
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Heo P, Yang TJ, Chung SC, Cheon Y, Kim JS, Park JB, Koo HM, Cho KM, Seo JH, Park JC, Kweon DH. Simultaneous integration of multiple genes into the Kluyveromyces marxianus chromosome. J Biotechnol 2013; 167:323-5. [PMID: 23845272 DOI: 10.1016/j.jbiotec.2013.06.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/14/2013] [Accepted: 06/28/2013] [Indexed: 10/26/2022]
Abstract
While Kluyveromyces marxianus is a promising yeast strain for biotechnological applications, genetic engineering of this strain is still challenging, especially when multiple genes are to be transformed. Sequential gene integration, which takes advantage of repetitive insertion/excision of the URA3 gene as a marker, has been the best option until now, because the URA3-deletion mutant is the only precondition for this method. However, we found that the introduced gene is co-excised during the URA3 excision step for next gene introduction, resulting in a very low cumulative probability (<1.57×10⁻⁶ % for 4 genes) of integrating all genes of interest. To overcome this extremely low probability, and to reduce labor and time, all 4 genes were simultaneously transformed. Surprisingly, the infamously high 'non-homologous end joining' activity of K. marxianus enabled simultaneous integration of all 4 genes in a single step, with a probability of 7.9%. Various K. marxianus strains could also be similarly transformed. Our finding not only reduces the labor and time required for such procedures, but also removes a number of preconditions, such as pre-made vectors, selection markers and knockout mutants, which are needed to introduce many genes into K. marxianus.
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Affiliation(s)
- Paul Heo
- Department of Genetic Engineering and Center for Human Interface Nano Technology, Sungkyunkwan University, Suwon 440-746, South Korea
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Characterization of Saccharomyces cerevisiae promoters for heterologous gene expression in Kluyveromyces marxianus. Appl Microbiol Biotechnol 2012; 97:2029-41. [PMID: 22911091 DOI: 10.1007/s00253-012-4306-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/12/2012] [Accepted: 07/12/2012] [Indexed: 10/28/2022]
Abstract
Kluyveromyces marxianus is now considered one of the best choices of option for industrial applications of yeast because the strain is able to grow at high temperature, utilizes various carbon sources, and grows fast. However, the use of K. marxianus as a host for industrial applications is still limited. This limitation is largely due to a lack of knowledge on the characteristics of the promoters since the time and amount of protein expression is strongly dependent on the promoter employed. In this study, four well-known constitutive promoters (P(CYC), P(TEF), P(GPD), and P(ADH)) of Saccharomyces cerevisiae were characterized in K. marxianus in terms of protein expression level and their stochastic behavior. After constructing five URA3-auxotrophic K. marxianus strains and a plasmid vector, four cassettes each comprising one of the promoters--the gene for the green fluorescence protein (GFP)--CYC1 terminator (T(CYC)) were inserted into the vector. GFP expression under the control of each one of the promoters was analyzed by reverse transcription PCR, fluorescence microscopy, and flow cytometer. Using these combined methods, the promoter strength was determined to be in the order of P(GPD) > P(ADH) ∼ P(TEF) >> P(CYC). All promoters except for the P(CYC) exhibited three distinctive populations, including non-expressing cells, weakly expressing cells, and strongly expressing cells. The relative ratios between populations were strongly dependent on the promoter and culture time. Forward scattering was independent of GFP fluorescence intensity, indicating that the different fluorescence intensities were not just due to different cell sizes derived from budding. It also excluded the possibility that the non-expressing cells resulted from plasmid loss because plasmid stability was maintained at almost 100 % over the culture time. The same cassettes, cloned into a single copy plasmid pRS416 and transformed into S. cerevisiae, showed only one population. When the cassettes were integrated into the chromosome, the stochastic behavior was markedly reduced. These combined results imply that the gene expression stochasticity should be overcome in order to use this strain for delicate metabolic engineering, which would require the co-expression of several genes.
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Abstract
Most strains of the yeast Saccharomyces cerevisiae contain many copies of a 2-μm plasmid, a selfish autonomously replicating DNA that relies on two different mechanisms to ensure its survival. One of these mechanisms involves the high fidelity segregation of the plasmids to daughter cells during cell division, a property that is starkly reminiscent of centromeres. A new study reported in this issue (see Hajra et al. on p. 779) demonstrates that this high fidelity is achieved by the 2-μm plasmid, effectively recruiting the centromeric histone Cse4 from its host yeast cell to forge its own centromere and finally revealing how the 2-μm plasmid has survived in budding yeasts over millions of years.
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Affiliation(s)
- Harmit S Malik
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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Rodicio R, Koch S, Schmitz HP, Heinisch JJ. KlRHO1 and KlPKC1 are essential for cell integrity signalling in Kluyveromyces lactis. Microbiology (Reading) 2006; 152:2635-2649. [PMID: 16946259 DOI: 10.1099/mic.0.29105-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell integrity in yeasts is ensured by a rigid cell wall whose synthesis is triggered by a MAP kinase-mediated signal-transduction cascade. Upstream regulatory components of this pathway inSaccharomyces cerevisiaeinvolve a single protein kinase C, which is regulated by interaction with the small GTPase Rho1. Here, two genes were isolated which encode these proteins fromKluyveromyces lactis(KlPKC1andKlRHO1). Sequencing showed ORFs which encode proteins of 1161 and 208 amino acids, respectively. The deduced proteins shared 59 and 85 % overall amino acid identities, respectively, with their homologues fromS. cerevisiae. Null mutants in both genes were non-viable, as shown by tetrad analyses of the heterozygous diploid strains. Overexpression of theKlRHO1gene under the control of theScGAL1promoter severely impaired growth in bothS. cerevisiaeandK. lactis. On the other hand, a similar construct withKlPKC1did not show a pronounced phenotype. Two-hybrid analyses showed interaction between Rho1 and Pkc1 for theK. lactisproteins and theirS. cerevisiaehomologues. A green fluorescent protein (GFP) fusion to the C-terminal end of KlPkc1 located the protein to patches in the growing bud, and at certain stages of the division process also to the bud neck. N-terminal GFP fusions to KlRho1 localized mainly to the cell surface (presumably the cytoplasmic side of the plasma membrane) and to the vacuole, with some indications of traffic from the former to the latter. Thus, KlPkc1 and KlRho1 have been shown to serve vital functions inK. lactis, to interact in cell integrity signalling and to traffic between the plasma membrane and the vacuole.
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Affiliation(s)
- Rosaura Rodicio
- Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo, 33006 Oviedo, Spain
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
| | - Sabrina Koch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
| | - Hans-Peter Schmitz
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
| | - Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
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Salani F, Bianchi MM. Production of glucoamylase in pyruvate decarboxylase deletion mutants of the yeast Kluyveromyces lactis. Appl Microbiol Biotechnol 2005; 69:564-72. [PMID: 16175368 DOI: 10.1007/s00253-005-0148-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Revised: 08/18/2005] [Accepted: 08/19/2005] [Indexed: 10/25/2022]
Abstract
Yeasts are widely used as hosts for the production of diverse heterologous proteins ranging from laboratory scale to industrial scale. The aim of this work is to provide new tools for the production of heterologous proteins in the yeast Kluyveromyces lactis. The promoter of the single gene (KlPDC1) encoding pyruvate decarboxylase is strong, inducible, and responsive to the presence of fermentable sugars and anoxic conditions in this yeast. Expression of KlPDC1 is repressed by ethanol and by autoregulation, a mechanism that involves protein KlPdc1. We constructed a heterologous gene expression cassette for a secreted protein (glucoamylase, GAM) under the control of the KlPDC1 promoter on a stable multicopy plasmid. GAM production by wild-type transformed strains was compared with that of klpdc1-deleted transformants. We obtained higher GAM production in the latter strains, which was due to continued expression of the GAM gene during the stationary phase rather than due to GAM transcription levels higher than the wild-type strains during growth phase. This finding opens new perspectives on the physiology of the stationary phase in K. lactis and suggests the possibility of using high-cell-density approaches for the efficient production of heterologous proteins with this yeast.
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Affiliation(s)
- Francesca Salani
- Centre of Excellence in Molecular Biology and Medicine, University of Rome La Sapienza, Rome, 00185, Italy
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Cai XP, Zhang J, Yuan HY, Fang ZA, Li YY. Secretory expression of heterologous protein in Kluyveromyces cicerisporus. Appl Microbiol Biotechnol 2004; 67:364-9. [PMID: 15614561 DOI: 10.1007/s00253-004-1834-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 10/02/2004] [Accepted: 11/06/2004] [Indexed: 10/26/2022]
Abstract
To explore the potential of heterologous protein expression in Kluyveromyces cicerisporus, three expression plasmids, pUK1-PIT, pUKD-PIT and pUKD-S-PIT, based on the vector pUK1 or pUKD were constructed and transformed, respectively, into yeast strain K. cicerisporus Y179U. Human interferon alpha-2a, used as an example protein, was successfully expressed and secreted by transformant Y179U/pUKD-PIT and Y179U/pUKD-S-PIT. In the flask culture, strain Y179U/pUKD-S-PIT could express interferon at 60 mg/l. The stability of plasmid pUKD-S-PIT in the host was higher than that of pUKD-PIT. This was consistent with their expression levels of interferon. There were two interferon-related bands found by Western blotting analysis. The possible reason for this is discussed.
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Affiliation(s)
- X P Cai
- Institute of Genetics, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
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Bartkeviciute D, Sasnauskas K. Studies of yeast Kluyveromyces lactis mutations conferring super-secretion of recombinant proteins. Yeast 2003; 20:1-11. [PMID: 12489121 DOI: 10.1002/yea.935] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have isolated mutants responsible for a super-secretion phenotype in Kluyveromyces lactis using the gene coding for a Bacillus amyloliquefaciens alpha-amylase as a marker for secretion. These mutations defined two groups, dominant and recessive. The recessive mutant strain, which secreted the heterologous protein in five-fold excess compared to the wild-type strain, was used for the cloning of genes, restraining the super-secreting phenotype. In screening for genes affecting super-secreting phenotype, we found that multiple copies of 10 different independently isolated DNA sequences suppressed the super-secreting phenotype. The first among the genes characterized, named KlSEL1 ('secretion lowering') showed homology to Saccharomyces cerevisiae ORF YML013w. The KlSEL1 gene is predicted to encode a polypeptide of 620 amino acid residues containing a putative transmembrane domain and UBX domain, characteristic for the ubiquitin-regulatory proteins. We demonstrated that the disruption of the SEL1 orthologues in K. lactis and S. cerevisiae conferred the super-secreting phenotype. SEL1 isolated from S. cerevisiae suppressed the super-secretion phenotype in K. lactis klsel1 strain, likewise homologous KlSEL1. No other phenotypic features for strains lacking the SEL1 gene were noticed except for the S. cerevisiae mutant growth being notably slower than in a wt strain. No growth changes were observed in the K. lactis klsel1 mutant. The set of genes (suppressors of over-secreting phenotype) could be attractive for further analysis of gene functions, super-secreting mechanisms and construction of new strains. This collection could be useful for the expedient construction of reduced yeast genomes, optimized for heterologous protein secretion.
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Schaffrath R, Breunig KD. Genetics and molecular physiology of the yeast Kluyveromyces lactis. Fungal Genet Biol 2000; 30:173-90. [PMID: 11035939 DOI: 10.1006/fgbi.2000.1221] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With the recent development of powerful molecular genetic tools, Kluyveromyces lactis has become an excellent alternative yeast model organism for studying the relationships between genetics and physiology. In particular, comparative yeast research has been providing insights into the strikingly different physiological strategies that are reflected by dominance of respiration over fermentation in K. lactis versus Saccharomyces cerevisiae. Other than S. cerevisiae, whose physiology is exceptionally affected by the so-called glucose effect, K. lactis is adapted to aerobiosis and its respiratory system does not underlie glucose repression. As a consequence, K. lactis has been successfully established in biomass-directed industrial applications and large-scale expression of biotechnically relevant gene products. In addition, K. lactis maintains species-specific phenomena such as the "DNA-killer system, " analyses of which are promising to extend our knowledge about microbial competition and the fundamentals of plasmid biology.
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Affiliation(s)
- R Schaffrath
- Institut für Genetik, Martin-Luther-Universität-Wittenberg, D-06099 Halle(Saale), Germany.
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Bartkevi&cbreve;iūte D, Siek&sbreve;tele R, Sasnauskas K. Heterologous expression of the Kluyveromyces marxianus endopolygalacturonase gene (EPG1) using versatile autonomously replicating vector for a wide range of host. Enzyme Microb Technol 2000; 26:653-656. [PMID: 10862869 DOI: 10.1016/s0141-0229(00)00155-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A versatile plasmid shuttle vector system pKDU7 was constructed, which is useful for the heterologous gene expression in a wide range of Kluyveromyces and Saccharomyces strains. This cloning vector was constructed using the 1.6-µm circular plasmid pKD1 of Kluyveromyces drosophilarum, the URA3 gene of K. marxianus as well as the pUC19 sequences. The stability of vector in transformants strongly depends on the integrity of the functionally important elements of pKD1. It was shown by comparison of three recombinant vectors, which possessed the pKD1 sequence inserted in different ways. The efficient transformation and stability maintenance of the vector constructed in various strains of Kluyveromyces and Saccharomyces was shown by the expression of the EPG1 gene of the Kluyveromyces marxianus encoding pectin-degrading endopolygalacturonase.
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Abstract
A gratuitous induction system based on the strong, indigenous LAC4 promoter was developed for Kluyveromyces lactis. To prevent consumption of the inducer galactose, a strain with a gal1-209 mutation was employed; this mutation disables the galactokinase function but retains the regulatory function for induction. The Escherichia coli lacZ gene (encoding beta-galactosidase) is functional in K. lactis and was used as the reporter gene downstream of the LAC4 promoter on a multicopy plasmid. The gal1-209 strain exhibited several unexpected phenomena, including partial consumption of the inducer galactose (although at a much slower rate relative to GAL1 strains) and growth inhibition at high concentrations of galactose. These unusual characteristics, however, did not prevent the successful construction of a strong gratuitous induction system. Due to the low rate of inducer consumption for the gratuitous strain, very low concentrations of galactose (1:20 galactose:glucose) resulted in high-level induction. Under these conditions, beta-galactosidase specific and volumetric activities were 4.2- and 5.5-fold higher, respectively, than those for the "GAL1" nongratuitous strain. This research demonstrated the improved productivity possible via LAC4 promoter-based gratuitous induction (and thus a more stable inducer concentration). The effects of various carbon source concentrations on growth and induction were also determined.
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Affiliation(s)
- H B Hsieh
- Department of Chemical and Biochemical Engineering & Materials Science, University of California, Irvine, California 92697-2575, USA
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Morlino GB, Tizzani L, Fleer R, Frontali L, Bianchi MM. Inducible amplification of gene copy number and heterologous protein production in the yeast Kluyveromyces lactis. Appl Environ Microbiol 1999; 65:4808-13. [PMID: 10543790 PMCID: PMC91648 DOI: 10.1128/aem.65.11.4808-4813.1999] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Heterologous protein production can be doubled by increasing the copy number of the corresponding heterologous gene. We constructed a host-vector system in the yeast Kluyveromyces lactis that was able to induce copy number amplification of pKD1 plasmid-based vectors upon expression of an integrated copy of the plasmid recombinase gene. We increased the production and secretion of two heterologous proteins, glucoamylase from the yeast Arxula adeninivorans and mammalian interleukin-1beta, following gene dosage amplification when the heterologous genes were carried by pKD1-based vectors. The choice of the promoters for expression of the integrated recombinase gene and of the episomal heterologous genes are critical for the mitotic stability of the host-vector system.
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Affiliation(s)
- G B Morlino
- Department of Cell and Developmental Biology, University of Rome "La Sapienza," Rome 00185, Italy
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He S, Fox TD. Mutations affecting a yeast mitochondrial inner membrane protein, pnt1p, block export of a mitochondrially synthesized fusion protein from the matrix. Mol Cell Biol 1999; 19:6598-607. [PMID: 10490599 PMCID: PMC84629 DOI: 10.1128/mcb.19.10.6598] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The machinery that inserts mitochondrially encoded proteins into the inner membrane and translocates their hydrophilic domains through the membrane is poorly understood. We have developed a genetic screen for Saccharomyces cerevisiae mutants defective in this export process. The screen is based on the fact that the hydrophilic polypeptide Arg8(m)p is exported from the matrix if it is synthesized within mitochondria as a bifunctional Cox2p-Arg8(m)p fusion protein. Since export of Arg8(m)p causes an Arg(-) phenotype, defective mutants can be selected as Arg(+). Here we show that mutations in the nuclear gene PNT1 block the translocation of mitochondrially encoded fusion proteins across the inner membrane. Pnt1p is a mitochondrial integral inner membrane protein that appears to have two hydrophilic domains in the matrix, flanking a central hydrophobic hairpin-like anchor. While an S. cerevisiae pnt1 deletion mutant was more sensitive to H(2)O(2) than the wild type was, it was respiration competent and able to export wild-type Cox2p. However, deletion of the PNT1 orthologue from Kluyveromyces lactis, KlPNT1, caused a clear nonrespiratory phenotype, absence of cytochrome oxidase activity, and a defect in the assembly of KlCox2p that appears to be due to a block of C-tail export. Since PNT1 was previously described as a gene affecting resistance to the antibiotic pentamidine, our data support a mitochondrial target for this drug.
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Affiliation(s)
- S He
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703, USA
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Bui DM, Kunze I, Horstmann C, Schmidt T, Breunig KD, Kunze G. Expression of the Arxula adeninivorans glucoamylase gene in Kluyveromyces lactis. Appl Microbiol Biotechnol 1996; 45:102-6. [PMID: 8920185 DOI: 10.1007/s002530050655] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The glucoamylase gene of the yeast Arxula adeninivorans was expressed in Kluyveromyces lactis by using the GAP promoter from Saccharomyces cerevisiae and a multicopy plasmid vector. The transformants secreted 90.1% of the synthesized glucoamylase into the culture medium. The secreted glucoamylase activities are about 20 times higher in comparison to those of Saccharomyces cerevisiae transformants using the same promoter. Secreted glucoamylase possesses identical N-terminal amino acid sequences to those secreted by A. adeninivorans showing that cleavage of the N-terminal signal peptide takes place at the same site. Biochemical characteristics of glucoamylase expressed by K. lactis and A. adeninivorans are very similar.
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Affiliation(s)
- D M Bui
- Institut für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany
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Hensing MC, Rouwenhorst RJ, Heijnen JJ, van Dijken JP, Pronk JT. Physiological and technological aspects of large-scale heterologous-protein production with yeasts. Antonie Van Leeuwenhoek 1995; 67:261-79. [PMID: 7778895 DOI: 10.1007/bf00873690] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Commercial production of heterologous proteins by yeasts has gained considerable interest. Expression systems have been developed for Saccharomyces cerevisiae and a number of other yeasts. Generally, much attention is paid to the molecular aspects of heterologous-gene expression. The success of this approach is indicated by the high expression levels that have been obtained in shake-flask cultures. For large-scale production however, possibilities and restrictions related to host-strain physiology and fermentation technology also have to be considered. In this review, these physiological and technological aspects have been evaluated with the aid of numerical simulations. Factors that affect the choice of a carbon substrate for large-scale production involve price, purity and solubility. Since oxygen demand and heat production (which are closely linked) limit the attainable growth rate in large-scale processes, the biomass yield on oxygen is also a key parameter. Large-scale processes impose restrictions on the expression system. Many promoter systems that work well in small-scale systems cannot be implemented in industrial environments. Furthermore, large-scale fed-batch fermentations involve a substantial number of generations. Therefore, even low expression-cassette instability has a profound effect on the overall productivity of the system. Multicopy-integration systems may provide highly stable expression systems for industrial processes. Large-scale fed-batch processes are typically performed at a low growth rate. Therefore, effects of a low growth rate on the physiology and product formation rates of yeasts are of key importance. Due to the low growth rates in the industrial process, a substantial part of the substrate carbon is expended to meet maintenance-energy requirements. Factors that reduce maintenance-energy requirements will therefore have a positive effect on product yield. The relationship between specific growth rate and specific product formation rate (kg product.[kg biomass]-1.h-1) is the main factor influencing production levels in large-scale production processes. Expression systems characterized by a high specific rate of product formation at low specific growth rates are highly favourable for large-scale heterologous-protein production.
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Affiliation(s)
- M C Hensing
- Department of Microbiology and Enzymology, Kluyver Laboratory of Biotechnology, Delft University of Technology, The Netherlands
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Swinkels BW, van Ooyen AJ, Bonekamp FJ. The yeast Kluyveromyces lactis as an efficient host for heterologous gene expression. Antonie Van Leeuwenhoek 1993; 64:187-201. [PMID: 8092859 DOI: 10.1007/bf00873027] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Several different yeast species have been developed into systems for efficient heterologous gene expression. In this paper we review foreign gene expression in the dairy yeast Kluyveromyces lactis. This yeast presents several advantageous properties in comparison to other yeast species. These include its impressive secretory capacities, its excellent fermentation characteristics on large scale, its food grade status and the availability of both episomal and integrative expression vectors. Moreover, in contrast to the methylotrophic yeasts that are frequently used for the expression of foreign genes, K. lactis does not require explosion-proof fermentation equipment. Here, we present an overview of the available tools for heterologous gene expression in K. lactis (available promoters, vector systems, etc). Also, the production of prochymosin, human serum albumin and pancreatic phospholipase by K. lactis is discussed in more detail, and used to rate the achievements of K. lactis with respect to other micro-organisms in which these proteins have been produced.
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Affiliation(s)
- B W Swinkels
- Gist-Brocades B.V., Research and Development, Delft, The Netherlands
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Bianchi MM. Site-specific recombination of the circular 2 microns-like plasmid pKD1 requires integrity of the recombinase gene A and of the partitioning genes B and C. J Bacteriol 1992; 174:6703-6. [PMID: 1400222 PMCID: PMC207658 DOI: 10.1128/jb.174.20.6703-6706.1992] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In the circular plasmid pKD1, which stably replicates in Kluyveromyces lactis, the three open reading frames encode a site-specific recombinase (gene A) and two proteins involved in mitotic stability (genes B and C). A recombination analysis of plasmids in which gene B or C is inactivated reveals that unlike the 2 microns plasmid of Saccharomyces cerevisiae, these genes are also required for the site specificity of plasmid recombination.
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Affiliation(s)
- M M Bianchi
- Department of Cell and Developmental Biology, University of Rome, La Sapienza, Italy
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Bergkamp RJ, Kool IM, Geerse RH, Planta RJ. Multiple-copy integration of the alpha-galactosidase gene from Cyamopsis tetragonoloba into the ribosomal DNA of Kluyveromyces lactis. Curr Genet 1992; 21:365-70. [PMID: 1326415 DOI: 10.1007/bf00351696] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have developed a vector system for high-copy-number integration into the ribosomal DNA of the yeast Kluyveromyces lactis. This system is analogous to the pMIRY-system developed for Saccharomyces cerevisiae. Plasmids containing a portion of K. lactis rDNA for targeted homologous recombination, as well as the S. cerevisiae TRP1 gene with various promoter deletions, were constructed and, after transformation to K. lactis, analyzed for both copy number and stability. These plasmids were found to be present in about 60 copies per cell and were stably maintained during growth under non-selective conditions. Using this vector system, we expressed a fusion construct containing the S. cerevisiae GAL7 promoter, the SUC2 (invertase) signal sequence and the gene coding for alpha-galactosidase from the plant Cyamopsis tetragonoloba. Although the maximum copy number of these integrated plasmids was only about 15, we nevertheless obtained a high level of alpha-galactosidase production (250 mg/l) with a secretion efficiency of about 95%. When compared to extrachromosomal K. lactis vectors containing the same fusion construct, the multicopy integrants showed a much higher alpha-galactosidase production level and a considerably higher stability under non-selective conditions.
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Affiliation(s)
- R J Bergkamp
- Laboratorium voor Biochemie en Moleculaire Biologie, Vrije Universiteit, Amsterdam, The Netherlands
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