scholarly journals RPD3 and UME6 are involved in the activation of PDR5 transcription and pleiotropic drug resistance in ρ0 cells of Saccharomyces cerevisiae

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yoichi Yamada

Abstract Background In Saccharomyces cerevisiae, the retrograde signalling pathway is activated in ρ0/− cells, which lack mitochondrial DNA. Within this pathway, the activation of the transcription factor Pdr3 induces transcription of the ATP-binding cassette (ABC) transporter gene, PDR5, and causes pleiotropic drug resistance (PDR). Although a histone deacetylase, Rpd3, is also required for cycloheximide resistance in ρ0/− cells, it is currently unknown whether Rpd3 and its DNA binding partners, Ume6 and Ash1, are involved in the activation of PDR5 transcription and PDR in ρ0/− cells. This study investigated the roles of RPD3, UME6, and ASH1 in the activation of PDR5 transcription and PDR by retrograde signalling in ρ0 cells. Results ρ0 cells in the rpd3∆ and ume6∆ strains, with the exception of the ash1∆ strain, were sensitive to fluconazole and cycloheximide. The PDR5 mRNA levels in ρ0 cells of the rpd3∆ and ume6∆ strains were significantly reduced compared to the wild-type and ash1∆ strain. Transcriptional expression of PDR5 was reduced in cycloheximide-exposed and unexposed ρ0 cells of the ume6∆ strain; the transcriptional positive response of PDR5 to cycloheximide exposure was also impaired in this strain. Conclusions RPD3 and UME6 are responsible for enhanced PDR5 mRNA levels and PDR by retrograde signalling in ρ0 cells of S. cerevisiae.

1999 ◽  
Vol 147 (2) ◽  
pp. 235-246 ◽  
Author(s):  
Anton A. Titov ◽  
Günter Blobel

We discovered a nuclear import pathway mediated by the product of the previously identified Saccharomyces cerevisiae gene PDR6 (pleiotropic drug resistance). This gene product functions as a karyopherin (Kap) for nuclear import. Consistent with previously proposed nomenclature, we have renamed this gene KAP122. Kap122p was localized both to the cytoplasm and the nucleus. As a prominent import substrate of Kap122p, we identified the complex of the large and small subunit (Toa1p and Toa2p, respectively) of the general transcription factor IIA (TFIIA). Recombinant GST-Kap122p formed a complex with recombinant His6-Toa1p/Toa2p. In wild-type cells, Toa1p and Toa2p were localized to the nucleus. Consistent with Kap122p being the principal Kap for import of the Toa1p–Toa2p complex, we found that deletion of KAP122 results in increased cytoplasmic localization of both Toa1p and Toa2p. Deletion of KAP122 is not lethal, although deletion of TOA1 and TOA2 is. Together these data suggest that Kap122p is the major Kap for the import of Toa1p–Toa2p into the nucleus. Like other substrate–Kap complexes, the Toa1p/Toa2p/Kap122p complex isolated from yeast cytosol or reconstituted from recombinant proteins, was dissociated by RanGTP but not RanGDP. Kap122p bound to nucleoporins, specifically, to the peptide repeat–containing fragments of Nup1p and Nup2p.


2004 ◽  
Vol 48 (12) ◽  
pp. 4505-4512 ◽  
Author(s):  
Chia-Geun Chen ◽  
Yun-Liang Yang ◽  
Hsin-I Shih ◽  
Chia-Li Su ◽  
Hsiu-Jung Lo

ABSTRACT Overexpression of CDR1, an efflux pump, is one of the major mechanisms contributing to drug resistance in Candida albicans. CDR1 p-lacZ was constructed and transformed into a Saccharomyces cerevisiae strain so that the lacZ gene could be used as the reporter to monitor the activity of the CDR1 promoter. Overexpression of CaNDT80, the C. albicans homolog of S. cerevisiae NDT80, increases the β-galactosidase activity of the CDR1 p-lacZ construct in S. cerevisiae. Furthermore, mutations in CaNDT80 abolish the induction of CDR1 expression by antifungal agents in C. albicans. Consistently, the Candt80/Candt80 mutant is also more susceptible to antifungal drugs than the wild-type strain. Thus, the gene for CaNdt80 may be the first gene among the regulatory factors involved in drug resistance in C. albicans whose function has been identified.


2015 ◽  
Vol 11 (11) ◽  
pp. 3129-3136 ◽  
Author(s):  
Namal V. C. Coorey ◽  
James H. Matthews ◽  
David S. Bellows ◽  
Paul H. Atkinson

Identifying Saccharomyces cerevisiae genome-wide gene deletion mutants that confer hypersensitivity to a xenobiotic aids the elucidation of its mechanism of action (MoA).


Author(s):  
Huili Zhang ◽  
Jianwei He ◽  
Yanyan Ji ◽  
Akio Kato ◽  
Youtao Song

AbstractWe cultured calnexin-disrupted and wild-type Saccharomyces cerevisiae strains under conditions of heat stress. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced mRNA level of the molecular chaperone PDI in the ER was clearly higher in calnexin-disrupted S. cerevisiae relative to the wild type at 37°C, despite being almost the same in the two strains under normal conditions. The western blotting analysis for PDI protein expression in the ER yielded results that show a parallel in their mRNA levels in the two strains. We suggest that PDI may interact with calnexin under heat stress conditions, and that the induction of PDI in the ER can recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast.


2000 ◽  
Vol 182 (24) ◽  
pp. 7007-7013 ◽  
Author(s):  
Marijke A. H. Luttik ◽  
Peter Kötter ◽  
Florian A. Salomons ◽  
Ida J. van der Klei ◽  
Johannes P. van Dijken ◽  
...  

ABSTRACT The Saccharomyces cerevisiae ICL1 gene encodes isocitrate lyase, an essential enzyme for growth on ethanol and acetate. Previous studies have demonstrated that the highly homologousICL2 gene (YPR006c) is transcribed during the growth of wild-type cells on ethanol. However, even when multiple copies are introduced, ICL2 cannot complement the growth defect oficl1 null mutants. It has therefore been suggested thatICL2 encodes a nonsense mRNA or nonfunctional protein. In the methylcitrate cycle of propionyl-coenzyme A metabolism, 2-methylisocitrate is converted to succinate and pyruvate, a reaction similar to that catalyzed by isocitrate lyase. To investigate whetherICL2 encodes a specific 2-methylisocitrate lyase, isocitrate lyase and 2-methylisocitrate lyase activities were assayed in cell extracts of wild-type S. cerevisiae and of isogenicicl1, icl2, and icl1 icl2 null mutants. Isocitrate lyase activity was absent in icl1 andicl1 icl2 null mutants, whereas in contrast, 2-methylisocitrate lyase activity was detected in the wild type and single icl mutants but not in the icl1 icl2mutant. This demonstrated that ICL2 encodes a specific 2-methylisocitrate lyase and that the ICL1-encoded isocitrate lyase exhibits a low but significant activity with 2-methylisocitrate. Subcellular fractionation studies and experiments with an ICL2-green fluorescent protein fusion demonstrated that theICL2-encoded 2-methylisocitrate lyase is located in the mitochondrial matrix. Similar to that of ICL1, transcription of ICL2 is subject to glucose catabolite repression. In glucose-limited cultures, growth with threonine as a nitrogen source resulted in a ca. threefold induction ofICL2 mRNA levels and of 2-methylisocitrate lyase activity in cell extracts relative to cultures grown with ammonia as the nitrogen source. This is consistent with an involvement of the 2-methylcitrate cycle in threonine catabolism.


Yeast ◽  
2010 ◽  
Vol 27 (12) ◽  
pp. 983-998 ◽  
Author(s):  
René Verwaal ◽  
Yang Jiang ◽  
Jing Wang ◽  
Jean-Marc Daran ◽  
Gerhard Sandmann ◽  
...  

1984 ◽  
Vol 4 (7) ◽  
pp. 1238-1245
Author(s):  
M A Post-Beittenmiller ◽  
R W Hamilton ◽  
J E Hopper

The MEL1 gene in Saccharomyces cerevisiae is required for the production of alpha-galactosidase and for the catabolism of melibiose. Production of alpha-galactosidase is induced by galactose or melibiose and repressed by glucose. Inducibility is controlled by the positive and negative regulatory proteins GAL4 and GAL80, respectively. We have cloned the MEL1 gene to study its transcriptional expression and regulation. Evidence is presented that the MEL1 gene encodes alpha-galactosidase and that mel0 is a naturally occurring allele which lacks the alpha-galactosidase-coding sequences. RNAs prepared from wild-type cells and from cells carrying either the noninducible gal4-2 or GAL80S-100 allele grown on three different carbon sources were examined by Northern hybridization analyses. In wild-type cells under noninducing conditions, such as growth on glycerol-lactic acid, the MEL1 transcript was detected at a basal level which was 1 to 2% of the fully induced level. The basal level of expression was diminished in cells carrying the gal4-2 mutant allele but not in cells carrying the GAL80S-100 allele. The basal and induced RNA levels are repressed by glucose. Size determinations of the MEL1 transcripts detected in glycerol-lactic acid- and galactose-grown cells provided no evidence for two distinct transcripts.


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