Candida krusei is a pathogenic yeast species that is phylogenetically outside both of the well-studied yeast groups, whole genome duplication and CUG. Like all other yeast species, it needs to accumulate high amounts of potassium cations, which are needed for proliferation and many other cell functions. A search in the sequenced genomes of nine C. krusei strains revealed the existence of two highly conserved genes encoding putative potassium uptake systems. Both of them belong to the TRK family, whose members have been found in all the sequenced genomes of species from the Saccharomycetales subclade. Analysis and comparison of the two C. krusei Trk sequences revealed all the typical features of yeast Trk proteins but also an unusual extension of the CkTrk2 hydrophilic N-terminus. The expression of both putative CkTRK genes in Saccharomyces cerevisiae lacking its own potassium importers showed that only CkTrk1 is able to complement the absence of S. cerevisiae's own transporters and provide cells with a sufficient amount of potassium. Interestingly, a portion of the CkTrk1 molecules were localized to the vacuolar membrane. The presence of CkTrk2 had no evident phenotype, due to the fact that this protein was not correctly targeted to the S. cerevisiae plasma membrane. Thus, CkTrk2 is the first studied yeast Trk protein to date that was not properly recognized and targeted to the plasma membrane upon heterologous expression in S. cerevisiae.
- Klíčová slova
- Candida, Trk proteins, cation homeostasis, potassium uptake, yeast K+ transporters,
- MeSH
- Candida klasifikace genetika růst a vývoj metabolismus MeSH
- draslík metabolismus MeSH
- fungální proteiny genetika metabolismus MeSH
- fylogeneze MeSH
- genetická variace MeSH
- genom fungální genetika MeSH
- iontový transport MeSH
- proteiny přenášející kationty genetika metabolismus MeSH
- rekombinantní proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae klasifikace genetika růst a vývoj metabolismus MeSH
- Saccharomycetales klasifikace genetika MeSH
- testy genetické komplementace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- draslík MeSH
- fungální proteiny MeSH
- proteiny přenášející kationty MeSH
- rekombinantní proteiny MeSH
Hemolytic factor production by pathogenic Candida species is considered an important attribute in promoting survival within the mammal host through the ability to assimilate iron from the hemoglobin-heme group. Hemolytic capability has been evaluated for Candida species based on hemolysis zones on plate assay, analysis of hemolytic activity in liquid culture medium, and hemolysis from cell-free culture broth. The production of hemolytic factor is variable among Candida species, where C. parapsilosis is the less hemolytic species. In general, no intraspecies differences in beta-hemolytic activities are found among isolates belonging to C. albicans, C. glabrata, C. krusei, C. tropicalis, and C. parapsilosis. The production of hemolytic factor by Candida species is affected by several factors such as glucose supplementation in the culture medium, blood source, presence of erythrocytes and hemoglobin, and presence of electrolytes. On the basis of existing achievements, more researches are still needed in order to extend our knowledge about the biochemical nature of hemolytic molecules produced by distinct Candida species, the mechanism of hemolysis, and the molecular basis of the hemolytic factor expression.
- MeSH
- Candida klasifikace metabolismus fyziologie MeSH
- druhová specificita MeSH
- faktory virulence biosyntéza chemie MeSH
- hemolýza * MeSH
- kandidemie mikrobiologie patologie MeSH
- kultivační média chemie metabolismus MeSH
- lidé MeSH
- membránové glykoproteiny metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- faktory virulence MeSH
- kultivační média MeSH
- mannoproteins MeSH Prohlížeč
- membránové glykoproteiny MeSH
Yeasts, like other microorganisms, create numerous types of multicellular communities, which differ in their complexity, cell differentiation and in the occupation of different niches. Some of the communities, such as colonies and some types of biofilms, develop by division and subsequent differentiation of cells growing on semisolid or solid surfaces to which they are attached or which they can penetrate. Aggregation of individual cells is important for formation of other community types, such as multicellular flocs, which sediment to the bottom or float to the surface of liquid cultures forming flor biofilms, organized at the border between liquid and air under specific circumstances. These examples together with the existence of more obscure communities, such as stalks, demonstrate that multicellularity is widespread in yeast. Despite this fact, identification of mechanisms and regulations involved in complex multicellular behavior still remains one of the challenges of microbiology. Here, we briefly discuss metabolic differences between particular yeast communities as well as the presence and functions of various differentiated cells and provide examples of the ability of these cells to develop different ways to cope with stress during community development and aging.
To study the mechanisms involved in the maintenance of a linear mitochondrial genome we investigated the biochemical properties of the recombination protein Mgm101 from Candida parapsilosis. We show that CpMgm101 complements defects associated with the Saccharomyces cerevisiae mgm101-1(ts) mutation and that it is present in both the nucleus and mitochondrial nucleoids of C. parapsilosis. Unlike its S. cerevisiae counterpart, CpMgm101 is associated with the entire nucleoid population and is able to bind to a broad range of DNA substrates in a non-sequence specific manner. CpMgm101 is also able to catalyze strand annealing and D-loop formation. CpMgm101 forms a roughly C-shaped trimer in solution according to SAXS. Electron microscopy of a complex of CpMgm101 with a model mitochondrial telomere revealed homogeneous, ring-shaped structures at the telomeric single-stranded overhangs. The DNA-binding properties of CpMgm101, together with its DNA recombination properties, suggest that it can play a number of possible roles in the replication of the mitochondrial genome and the maintenance of its telomeres.
- MeSH
- buněčné jádro genetika metabolismus MeSH
- Candida genetika metabolismus MeSH
- DNA fungální genetika metabolismus MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- Escherichia coli genetika metabolismus MeSH
- exprese genu MeSH
- genom fungální * MeSH
- genom mitochondriální * MeSH
- homeostáza telomer MeSH
- klonování DNA MeSH
- mitochondriální proteiny genetika metabolismus MeSH
- mitochondrie genetika metabolismus MeSH
- multimerizace proteinu MeSH
- mutace MeSH
- regulace genové exprese u hub * MeSH
- rekombinace genetická MeSH
- rekombinantní proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- telomery chemie metabolismus MeSH
- testy genetické komplementace MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA fungální MeSH
- DNA vazebné proteiny MeSH
- MGM101 protein, S cerevisiae MeSH Prohlížeč
- mitochondriální proteiny MeSH
- rekombinantní proteiny MeSH
- Saccharomyces cerevisiae - proteiny MeSH
Yeast mtDNA is compacted into nucleoprotein structures called mitochondrial nucleoids (mt-nucleoids). The principal mediators of nucleoid formation are mitochondrial high-mobility group (HMG)-box containing (mtHMG) proteins. Although these proteins are some of the fastest evolving components of mt-nucleoids, it is not known whether the divergence of mtHMG proteins on the level of their amino acid sequences is accompanied by diversification of their biochemical properties. In the present study we performed a comparative biochemical analysis of yeast mtHMG proteins from Saccharomyces cerevisiae (ScAbf2p), Yarrowia lipolytica (YlMhb1p) and Candida parapsilosis (CpGcf1p). We found that all three proteins exhibit relatively weak binding to intact dsDNA. In fact, ScAbf2p and YlMhb1p bind quantitatively to this substrate only at very high protein to DNA ratios and CpGcf1p shows only negligible binding to dsDNA. In contrast, the proteins exhibit much higher preference for recombination intermediates such as Holliday junctions (HJ) and replication forks (RF). Therefore, we hypothesize that the roles of the yeast mtHMG proteins in maintenance and compaction of mtDNA in vivo are in large part mediated by their binding to recombination/replication intermediates. We also speculate that the distinct biochemical properties of CpGcf1p may represent one of the prerequisites for frequent evolutionary tinkering with the form of the mitochondrial genome in the CTG-clade of hemiascomycetous yeast species.
- Klíčová slova
- DNA compaction, DNA-binding protein, HMG-box containing protein, Holliday junction, mitochondrial DNA (mtDNA), mitochondrial nucleoid,
- MeSH
- Candida genetika metabolismus MeSH
- mitochondriální proteiny genetika metabolismus MeSH
- molekulární evoluce * MeSH
- proteiny s vysokou pohyblivostí genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- Yarrowia genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- mitochondriální proteiny MeSH
- proteiny s vysokou pohyblivostí MeSH
- Saccharomyces cerevisiae - proteiny MeSH
Lipid homeostasis is well-known in oleaginous yeasts, but there are few non-oleaginous yeast models apart from Saccharomyces cerevisiae. We are proposing the non-oleaginous yeast Candida zeylanoides QU 33 as model. The aim of this study was to investigate the influence of the carbon/nitrogen ratio and the type of nitrogen source upon oil accumulation by this yeast grown on shake flask cultures. The maximum biomass was obtained in yeast extract (2.39 ± 0.19 g/l), followed by peptone (2.24 ± 0.05 g/l), while the highest content of microbial oil (0.35 ± 0.01 g/l) and the maximum lipid yield (15.63%) were achieved with peptone. Oleic acid was the predominant cellular fatty acid in all culture media (>32.23%), followed by linoleic (>15.79%) and palmitic acids (>13.47%). The highest lipid yield using glucose and peptone was obtained at the C/N ratio of 200:1.
Numerous Δ12-, Δ15- and multifunctional membrane fatty acid desaturases (FADs) have been identified in fungi, revealing great variability in the enzymatic specificities of FADs involved in biosynthesis of polyunsaturated fatty acids (PUFAs). Here, we report gene isolation and characterization of novel Δ12/Δ15- and Δ15-FADs named CpFad2 and CpFad3, respectively, from the opportunistic pathogenic yeast Candida parapsilosis. Overexpression of CpFad3 in Saccharomyces cerevisiae strains supplemented with linoleic acid (Δ9,Δ12-18:2) and hexadecadienoic acid (Δ9,Δ12-16:2) leads to accumulation of Δ15-PUFAs, i.e., α-linolenic acid (Δ9,Δ12,Δ15-18:3) and hexadecatrienoic acid with an unusual terminal double bond (Δ9,Δ12,Δ15-16:3). CpFad2 produces a range of Δ12- and Δ15-PUFAs. The major products of CpFad2 are linoleic and hexadecadienoic acid (Δ9,Δ12-16:2), accompanied by α-linolenic acid and hexadecatrienoic acid (Δ9,Δ12,Δ15-16:3). Using GC/MS analysis of trimethylsilyl derivatives, we identified ricinoleic acid (12-hydroxy-9-octadecenoic acid) as an additional product of CpFad2. These results demonstrate that CpFAD2 is a multifunctional FAD and indicate that detailed analysis of fatty acid derivatives might uncover a range of enzymatic selectivities in other Δ12-FADs from budding yeasts (Ascomycota: Saccharomycotina).
- MeSH
- Candida metabolismus MeSH
- desaturasy mastných kyselin metabolismus MeSH
- fylogeneze MeSH
- kyselina linolová metabolismus MeSH
- kyseliny ricinolejové metabolismus MeSH
- molekulární sekvence - údaje MeSH
- nenasycené mastné kyseliny metabolismus MeSH
- Saccharomyces cerevisiae metabolismus MeSH
- sekvence aminokyselin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- desaturasy mastných kyselin MeSH
- kyselina linolová MeSH
- kyseliny ricinolejové MeSH
- nenasycené mastné kyseliny MeSH
- ricinoleic acid MeSH Prohlížeč
The virulence of Candida species depends on many environmental conditions, including extracellular pH and concentration of alkali metal cations. Tests of the tolerance/sensitivity of four pathogenic Candida species (C. albicans, C. dubliniensis, C. glabrata, and C. parapsilosis) to alkali metal cations under various growth conditions revealed significant differences among these species. Though all of them can be classified as rather osmotolerant yeast species, they exhibit different levels of tolerance to different salts. C. parapsilosis and C. albicans are the most salt-tolerant in general; C. dubliniensis is the least tolerant on rich YPD media and C. glabrata on acidic (pH 3.5) minimal YNB medium. C. dubliniensis is relatively salt-sensitive in spite of its ability to maintain as high intracellular K(+)/Na(+) ratio as its highly salt-tolerant relative C. albicans. On the other hand, C. parapsilosis can grow in the presence of very high external NaCl concentrations in spite of its high intracellular Na(+) concentrations (and thus lower K(+)/Na(+) ratio) and thus resembles salt-tolerant (halophilic) Debaryomyces hansenii.
- MeSH
- Candida albicans patogenita fyziologie MeSH
- Candida glabrata patogenita fyziologie MeSH
- Candida metabolismus patogenita fyziologie MeSH
- chlorid draselný analýza farmakologie MeSH
- chlorid lithný analýza farmakologie MeSH
- chlorid sodný analýza farmakologie MeSH
- druhová specificita MeSH
- soli MeSH
- tolerance k soli fyziologie MeSH
- virulence MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- chlorid draselný MeSH
- chlorid lithný MeSH
- chlorid sodný MeSH
- soli MeSH
Candida dubliniensis pathogenic species, which shares many phenotypic features with C. albicans, may be misidentified in the microbiology laboratory. The growth on DRBC agar at 25 degrees C was shown to be a new tool for differentiation between C. dubliniensis and C. albicans. All 27 isolates of C. dubliniensis showed in this medium rough colonies (peripheral hyphal fringes) and abundant chlamydospore production, while all 103 isolates of C. albicans showed smooth colonies without fringes or chlamydospores. DRBC agar allowed the differentiation of C. albicans from C. dubliniensis with 100 % sensitivity and specificity.
- MeSH
- agar analýza metabolismus MeSH
- Candida klasifikace růst a vývoj izolace a purifikace metabolismus MeSH
- kandidóza mikrobiologie MeSH
- kultivační média analýza metabolismus MeSH
- lidé MeSH
- mykologické určovací techniky metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- Názvy látek
- agar MeSH
- kultivační média MeSH
BACKGROUND: The virulence of Candida species depends on many environmental conditions. Extracellular pH and concentration of alkali metal cations belong among important factors. Nevertheless, the contribution of transporters mediating the exchange of alkali metal cations for protons across the plasma membrane to the cell salt tolerance and other physiological properties of various Candida species has not been studied so far. RESULTS: The tolerance/sensitivity of four pathogenic Candida species to alkali metal cations was tested and the role of one of the cation transporters in that tolerance (presumed to be the plasma-membrane Na+/H+ antiporter) was studied. The genes encoding these antiporters in the most and least salt sensitive species, C. dubliniensis and C. parapsilosis respectively, were identified, cloned and functionally expressed in the plasma membranes of Saccharomyces cerevisiae cells lacking their own cation exporters. Both CpCnh1 and CdCnh1 antiporters had broad substrate specificity and transported Na+, K+, Li+, and Rb+. Their activity in S. cerevisiae cells differed; CpCnh1p provided cells with a much higher salt tolerance than the CdCnh1 antiporter. The observed difference in activity was confirmed by direct measurements of sodium and potassium efflux mediated by these antiporters. CONCLUSION: We have cloned two genes encoding putative Na+/H+ antiporters in C. parapsilosis and C. dubliniensis, and characterized the transport properties of encoded proteins. Our results show that the activity of plasma-membrane Na+/H+ antiporters is one of the factors determining the tolerance of pathogenic Candida species to high external concentrations of alkali metal cations.
- MeSH
- alkalické kovy metabolismus MeSH
- Candida genetika růst a vývoj metabolismus patogenita MeSH
- draslík metabolismus MeSH
- fluorescenční mikroskopie MeSH
- fungální proteiny genetika metabolismus MeSH
- kationty metabolismus MeSH
- lithium metabolismus MeSH
- membránové proteiny genetika metabolismus MeSH
- molekulární sekvence - údaje MeSH
- Na(+)-H(+) antiport genetika metabolismus MeSH
- proteiny přenášející kationty genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika růst a vývoj metabolismus MeSH
- sekundární struktura proteinů MeSH
- sekvence nukleotidů MeSH
- soli metabolismus MeSH
- substrátová specifita MeSH
- superoxid dismutáza 1 MeSH
- superoxiddismutasa metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- alkalické kovy MeSH
- CNH1 protein, Candida albicans MeSH Prohlížeč
- draslík MeSH
- fungální proteiny MeSH
- kationty MeSH
- lithium MeSH
- membránové proteiny MeSH
- Na(+)-H(+) antiport MeSH
- NHA1 protein, S cerevisiae MeSH Prohlížeč
- proteiny přenášející kationty MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- soli MeSH
- superoxid dismutáza 1 MeSH
- superoxiddismutasa MeSH
