In yeast, the STB5 gene encodes a transcriptional factor belonging to binuclear cluster class (Zn2Cys6) of transcriptional regulators specific to ascomycetes. In this study, we prepared the Kluyveromyces lactis stb5Δ strain and assessed its responses to different stresses. We showed that KlSTB5 gene is able to complement the deficiencies of Saccharomyces cerevisiae stb5Δ mutant. The results of phenotypic analysis suggested that KlSTB5 gene deletion did not sensitize K. lactis cells to oxidative stress inducing compounds but led to Klstb5Δ resistance to 4-nitroquinoline-N-oxide and hygromycin B. Expression analysis indicated that the loss of KlSTB5 gene function induced the transcription of drug efflux pump encoding genes that might contribute to increased 4-nitroquinoline-N-oxide and hygromycin B tolerance. Our results show that KlStb5p functions as negative regulator of some ABC transporter genes in K. lactis.
- Klíčová slova
- Drug resistance, Kluyveromyces lactis, Oxidative stress, Transcriptional regulator,
- MeSH
- 4-nitrochinolin-1-oxid farmakologie MeSH
- delece genu MeSH
- fungální proteiny genetika metabolismus MeSH
- Kluyveromyces účinky léků genetika metabolismus MeSH
- oxidační stres účinky léků MeSH
- regulace genové exprese u hub účinky léků MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae účinky léků genetika metabolismus MeSH
- transkripční faktory genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 4-nitrochinolin-1-oxid MeSH
- fungální proteiny MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- Stb5 protein, S cerevisiae MeSH Prohlížeč
- transkripční faktory MeSH
Farnesol (FAR) has already demonstrated an inhibitory effect on Candida albicans biofilm. The aim of this work was to determine the effectiveness of externally added FAR in combination with fluconazole (FLC) on Candida albicans biofilm and on regulation of the ergosterol genes ERG20, ERG9, and ERG11. The effectiveness of compounds was determined by MTT assay and evaluated by the minimal inhibitory concentrations reducing a sessile biofilm to 50% activity (0.5 μg/mL and 200 μmol/L for FLC and FAR, respectively). These concentrations as well as 30 and 100 μmol/L FAR were selected for a study of the effectiveness of the FAR/FLC combination. The reduction in biofilm robustness mainly caused by the presence of 200 μmol/L FAR-alone or in combination with FLC-was accompanied by a significant inhibition of the yeast-to-hyphae transition that was observed by light microscopy and CLSM. Results from qRT-PCR indicated that while 30 μmol/L FAR only slightly regulated the expression of all 3 genes in the 48-h biofilm, the presence of 200 μmol/L FAR downregulated all the tested genes. However, the addition of 0.5 μg/mL of FLC to the samples with 200 μmol/L FAR restored the downregulation of the ERG20 and ERG11 genes to the control level. Moreover, the gene ERG9 was slightly upregulated. In summary, FAR acted via multiple effects on the C. albicans biofilm, but only a higher concentration of FAR proved to be effective.
- MeSH
- antifungální látky farmakologie MeSH
- biofilmy účinky léků růst a vývoj MeSH
- Candida albicans účinky léků růst a vývoj MeSH
- ergosterol genetika metabolismus MeSH
- farnesol farmakologie MeSH
- flukonazol farmakologie MeSH
- geny hub genetika MeSH
- hyfy účinky léků MeSH
- metabolické sítě a dráhy účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- regulace genové exprese u hub účinky léků MeSH
- synergismus léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antifungální látky MeSH
- ergosterol MeSH
- farnesol MeSH
- flukonazol MeSH
With emerging fungal infections and developing resistance, there is a need for understanding the mechanisms of resistance as well as its clinical impact while planning the treatment strategies. Several approaches could be taken to overcome the problems arising from the management of fungal diseases. Besides the discovery of novel effective agents, one realistic alternative is to enhance the activity of existing agents. This strategy could be achieved by combining existing antifungal agents with other bioactive substances with known activity profiles (combination therapy). Azole antifungals are the most frequently used class of substances used to treat fungal infections. Fluconazole is often the first choice for antifungal treatment. The aim of this work was to study potential synergy between azoles and 1,4-dihydropyridine-2,3,5-tricarboxylate (termed derivative H) in order to control fungal infections. This article points out the synergy between azoles and newly synthesized derivative H in order to fight fungal infections. Experiments confirmed the role of derivative H as substrate/inhibitor of fungal transporter Cdr1p relating to increased sensitivity to fluconazole. These findings, plus decreased expression of ERG11, are responsible for the synergistic effect.
- Klíčová slova
- ABC transporter, Antifungal agents, Efflux, Fungal infection, Synergy,
- MeSH
- ABC transportéry antagonisté a inhibitory genetika MeSH
- antifungální látky chemická syntéza farmakologie terapeutické užití MeSH
- Candida albicans účinky léků genetika MeSH
- dihydropyridiny chemická syntéza farmakologie terapeutické užití MeSH
- flukonazol farmakologie terapeutické užití MeSH
- fungální léková rezistence účinky léků MeSH
- fungální proteiny antagonisté a inhibitory genetika MeSH
- kandidóza farmakoterapie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- mutace MeSH
- regulace genové exprese u hub účinky léků MeSH
- sterol-14-demethylasa genetika MeSH
- synergismus léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 1,4-dihydropyridine MeSH Prohlížeč
- ABC transportéry MeSH
- antifungální látky MeSH
- dihydropyridiny MeSH
- flukonazol MeSH
- fungální proteiny MeSH
- sterol-14-demethylasa MeSH
The accumulation of glycerol is essential for yeast viability upon hyperosmotic stress. Here we show that the osmotolerant yeast Zygosaccharomyces rouxii has two genes, ZrSTL1 and ZrSTL2, encoding transporters mediating the active uptake of glycerol in symport with protons, contributing to cell osmotolerance and intracellular pH homeostasis. The growth of mutants lacking one or both transporters is affected depending on the growth medium, carbon source, strain auxotrophies, osmotic conditions and the presence of external glycerol. These transporters are localised in the plasma membrane, they transport glycerol with similar kinetic parameters and besides their expected involvement in the cell survival of hyperosmotic stress, they surprisingly both contribute to an efficient survival of hypoosmotic shock and to the maintenance of intracellular pH homeostasis under non-stressed conditions. Unlike STL1 in Sa. cerevisiae, the two Z. rouxii STL genes are not repressed by glucose, but their expression and activity are downregulated by fructose and upregulated by non-fermentable carbon sources, with ZrSTL1 being more influenced than ZrSTL2. In summary, both transporters are highly important, though Z. rouxii CBS 732(T) cells do not use external glycerol as a source of carbon.
- MeSH
- biologický transport MeSH
- delece genu MeSH
- fyziologický stres MeSH
- glycerol metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- mikrobiální viabilita MeSH
- organické látky metabolismus MeSH
- osmoregulace * MeSH
- osmotický tlak MeSH
- regulace genové exprese u hub účinky léků MeSH
- symportéry genetika metabolismus MeSH
- Zygosaccharomyces genetika růst a vývoj metabolismus fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- glycerol MeSH
- kultivační média MeSH
- organické látky MeSH
- symportéry MeSH
