scholarly journals Deletion of the trehalose tps1 gene in Kluyveromyces lactis does not impair growth in glucose

2020 ◽  
Vol 367 (10) ◽  
Author(s):  
Antonio M V Gomes ◽  
Ana Carolina A L Orlandi ◽  
Nádia S Parachin
Keyword(s):  
Dairy Products ◽  
Gene Disruption ◽  
Sole Carbon Source ◽  
Gene Deletion ◽  
Kluyveromyces Lactis ◽  
Growth Failure ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Tps1 Gene ◽  
Encoding Gene

ABSTRACT Trehalose is a non-reducing disaccharide composed of two α-glucose molecules and synthesized by an enzyme complex containing four subunits TPS1 (EC 2.4.1.15), TPS2 (EC 3.1.3.12), TPS3 and TSL1. First reports about trehalose classified this sugar as an energy reserve compound like glycogen. However, lately, trehalose is known to assist yeast cells during heat, osmotic and starvation stresses. In Saccharomyces cerevisiae, the deletion of the tps1 encoding gene eliminated the yeast ability to grow on glucose as the sole carbon source. Kluyveromyces lactis is a yeast present in various dairy products and is currently utilized for the synthesis of more than 40 industrial heterologous products. In this study, the deletion of the tps1 gene in K. lactis showed that unlike S. cerevisiae, tps1 gene disruption does not cause growth failure in glucose, galactose, or fructose. The µMAX rate values of K. lactis tps1Δ strains were equal than the non-disrupted strains, showing that the gene deletion does not affect the yeast growth. After gene disruption, the absence of trehalose into the metabolism of K. lactis was also confirmed.

scholarly journals Expression of an ATP-binding cassette transporter-encoding gene (YOR1) is required for oligomycin resistance in Saccharomyces cerevisiae.

1995 ◽  
Vol 15 (12) ◽  
pp. 6875-6883 ◽  
Author(s):  
D J Katzmann ◽  
T C Hallstrom ◽  
M Voet ◽  
W Wysock ◽  
J Golin ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Sequence Similarity ◽  
Yeast Cells ◽  
Atp Binding ◽  
Zinc Cluster ◽  
Atp Binding Cassette Transporter ◽  
Transporter Family ◽  
Encoding Gene ◽  
Atp Binding Cassette

Semidominant mutations in the PDR1 or PDR3 gene lead to elevated resistance to cycloheximide and oligomycin. PDR1 and PDR3 have been demonstrated to encode zinc cluster transcription factors. Cycloheximide resistance mediated by PDR1 and PDR3 requires the presence of the PDR5 membrane transporter-encoding gene. However, PDR5 is not required for oligomycin resistance. Here, we isolated a gene that is necessary for PDR1- and PDR3-mediated oligomycin resistance. This locus, designated YOR1, causes a dramatic elevation in oligomycin resistance when present in multiple copies. A yor1 strain exhibits oligomycin hypersensitivity relative to an isogenic wild-type strain. In addition, loss of the YOR1 gene blocks the elevation in oligomycin resistance normally conferred by mutant forms of PDR1 or PDR3. The YOR1 gene product is predicted to be a member of the ATP-binding cassette transporter family of membrane proteins. Computer alignment indicates that Yor1p shows striking sequence similarity with multidrug resistance-associated protein, Saccharomyces cerevisiae Ycf1p, and the cystic fibrosis transmembrane conductance regulator. Use of a YOR1-lacZ fusion gene indicates that YOR1 expression is responsive to PDR1 and PDR3. While PDR5 expression is strictly dependent on the presence of PDR1 or PDR3, control of YOR1 expression has a significant PDR1/PDR3-independent component. Taken together, these data indicate that YOR1 provides the link between transcriptional regulation by PDR1 and PDR3 and oligomycin resistance of yeast cells.

scholarly journals Conservation of the Prion Properties of Ure2p through Evolution

2003 ◽  
Vol 14 (8) ◽  
pp. 3449-3458 ◽  
Author(s):  
Agnès Baudin-Baillieu ◽  
Eric Fernandez-Bellot ◽  
Fabienne Reine ◽  
Eric Coissac ◽  
Christophe Cullin
Keyword(s):  
Functional Analysis ◽  
Candida Albicans ◽  
Gene Deletion ◽  
Yeast Species ◽  
Kluyveromyces Lactis ◽  
In Silico Analysis ◽  
Functional Domain ◽  
Extreme Situation ◽  
Homologous Genes ◽  
Silico Analysis

The yeast inheritable [URE3] element corresponds to a prion form of the nitrogen catabolism regulator Ure2p. We have isolated several orthologous URE2 genes in different yeast species: Saccharomyces paradoxus, S. uvarum, Kluyveromyces lactis, Candida albicans, and Schizosaccharomyces pombe. We show here by in silico analysis that the GST-like functional domain and the prion domain of the Ure2 proteins have diverged separately, the functional domain being more conserved through the evolution. The more extreme situation is found in the two S. pombe genes, in which the prion domain is absent. The functional analysis demonstrates that all the homologous genes except for the two S. pombe genes are able to complement the URE2 gene deletion in a S. cerevisiae strain. We show that in the two most closely related yeast species to S. cerevisiae, i.e., S. paradoxus and S. uvarum, the prion domains of the proteins have retained the capability to induce [URE3] in a S. cerevisiae strain. However, only the S. uvarum full-length Ure2p is able to behave as a prion. We also show that the prion inactivation mechanisms can be cross-transmitted between the S. cerevisiae and S. uvarum prions.

Enhancement of bifidobacteria survival by Williopsis saturnus var. saturnus in milk

2016 ◽  
Vol 7 (1) ◽  
pp. 135-144 ◽  
Author(s):  
A.Y.Y. Yeo ◽  
M.Z. Toh ◽  
S.Q. Liu
Keyword(s):  
Viable Cell ◽  
Oxygen Removal ◽  
Physical Contact ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Bifidobacterium Lactis ◽  
Enhancing Effect ◽  
Uht Milk ◽  
Williopsis Saturnus ◽  
Dairy Beverages

The viability of three strains of probiotic Bifidobacterium lactis that were inoculated into UHT milk was examined with and without the presence of the yeast, Williopsis saturnus var. saturnus NCYC 22, in polypropylene tubes at 30 °C. The B. lactis viable cell count for strains HN019 and BB-12 remained above 6.0 Log cfu/ml, while strain B94 had 5.7 Log cfu/ml after six weeks of incubation in the presence of the co-inoculated yeast. Incubating the bifidus milk without added yeast under anaerobic condition did not improve the survival of B. lactis HN019, indicating that oxygen removal may not be responsible for W. saturnus NCYC 22’s viability enhancing property. The addition of yeast supernatant or non-viable yeast also did not show any stabilising effects, suggesting that physical contact and/or interaction between viable W. saturnus and B. lactis plays an important role in sustaining the viability of the probiotic. W. saturnus NCYC 22 could increase the survival of B. lactis in bifidus milk under ambient temperature regardless of the initial concentration of yeast cells inoculated due to yeast growth. This study demonstrated the viability enhancing effect of viable W. saturnus NCYC 22 on B. lactis HN019, which could help towards extending the shelf-life of dairy beverages containing probiotic bifidobacteria.

scholarly journals Kluyveromyces lactis LAC4 Promoter Variants That Lack Function in Bacteria but Retain Full Function in K. lactis

2005 ◽  
Vol 71 (11) ◽  
pp. 7092-7098 ◽  
Author(s):  
Paul A. Colussi ◽  
Christopher H. Taron
Keyword(s):  
Dna Sequences ◽  
Transcription Initiation ◽  
Fluorescent Protein ◽  
Kluyveromyces Lactis ◽  
Targeted Mutagenesis ◽  
Yeast Cells ◽  
Heterologous Proteins ◽  
Gfp Expression ◽  
E Coli ◽  
Cloned Gene

ABSTRACT The strong LAC4 promoter (PLAC4) from Kluyveromyces lactis has been extensively used to drive expression of heterologous proteins in this industrially important yeast. A drawback of this expression method is the serendipitous ability of PLAC4 to promote gene expression in Escherichia coli. This can interfere with the process of assembling expression constructs in E. coli cells prior to their introduction into yeast cells, especially if the cloned gene encodes a protein that is detrimental to bacteria. In this study, we created a series of PLAC4 variants by targeted mutagenesis of three DNA sequences (PBI, PBII, and PBIII) that resemble the E. coli Pribnow box element of bacterial promoters and that reside immediately upstream of two E. coli transcription initiation sites associated with PLAC4. Mutation of PBI reduced the bacterial expression of a reporter protein (green fluorescent protein [GFP]) by ∼87%, whereas mutation of PBII and PBIII had little effect on GFP expression. Deletion of all three sequences completely eliminated GFP expression. Additionally, each promoter variant expressed human serum albumin in K. lactis cells to levels comparable to wild-type PLAC4. We created a novel integrative expression vector (pKLAC1) containing the PLAC4 variant lacking PBI and used it to successfully clone and express the catalytic subunit of bovine enterokinase, a protease that has historically been problematic in E. coli cells. The pKLAC1 vector should aid in the cloning of other potentially toxic genes in E. coli prior to their expression in K. lactis.

Kluyveromyces lactis killer toxin inhibits adenylate cyclase of sensitive yeast cells

Nature ◽  
1983 ◽  
Vol 304 (5925) ◽  
pp. 464-466 ◽  
Author(s):  
Yuji Sugisaki ◽  
Norio Gunge ◽  
Kenji Sakaguchi ◽  
Makari Yamasaki ◽  
Gakuzo Tamura
Keyword(s):  
Adenylate Cyclase ◽  
Kluyveromyces Lactis ◽  
Killer Toxin ◽  
Yeast Cells

The stimulation of yeast growth and respiration by compounds produced by yeast cells irradiated with ultraviolet light

1952 ◽  
Vol 40 (2) ◽  
pp. 269-278 ◽  
Author(s):  
S. James Adelstein ◽  
Falls B. Hershey ◽  
John R. Loofbourow ◽  
Irwin W. Sizer
Keyword(s):  
Ultraviolet Light ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Stimulation Of

scholarly journals Identification and analysis of a Saccharomyces cerevisiae copper homeostasis gene encoding a homeodomain protein.

1994 ◽  
Vol 14 (12) ◽  
pp. 7792-7804 ◽  
Author(s):  
S A Knight ◽  
K T Tamai ◽  
D J Kosman ◽  
D J Thiele
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Copper Resistance ◽  
Yeast Cells ◽  
Homeodomain Protein ◽  
Mrna Levels ◽  
Reading Frame ◽  
Cup1 Gene ◽  
Intracellular Copper

Yeast metallothionein, encoded by the CUP1 gene, and its copper-dependent transcriptional activator ACE1 play a key role in mediating copper resistance in Saccharomyces cerevisiae. Using an ethyl methanesulfonate mutant of a yeast strain in which CUP1 and ACE1 were deleted, we isolated a gene, designated CUP9, which permits yeast cells to grow at high concentrations of environmental copper, most notably when lactate is the sole carbon source. Disruption of CUP9, which is located on chromosome XVI, caused a loss of copper resistance in strains which possessed CUP1 and ACE1, as well as in the cup1 ace1 deletion strain. Measurement of intracellular copper levels of the wild-type and cup9-1 mutant demonstrated that total intracellular copper concentrations were unaffected by CUP9. CUP9 mRNA levels were, however, down regulated by copper when yeast cells were grown with glucose but not with lactate or glycerol-ethanol as the sole carbon source. This down regulation was independent of the copper metalloregulatory transcription factor ACE1. The DNA sequence of CUP9 predicts an open reading frame of 306 amino acids in which a 55-amino-acid sequence showed 47% identity with the homeobox domain of the human proto-oncogene PBX1, suggesting that CUP9 is a DNA-binding protein which regulates the expression of important copper homeostatic genes.

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