In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp1 protein is 520 amino acids long and is comparable to the Ytp1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtp1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Deltamtp1 mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.
Fungal Proteins ; genetics ; physiology ; Genes, Fungal ; Magnaporthe ; genetics ; Membrane Proteins ; genetics ; Oryza ; microbiology ; Promoter Regions, Genetic

Aspergillus niger is an important industrial workhorse with extensive application in the sectors of industrial enzymes, heterogeneous proteins, organic acids and etc. The disclosure of its genomic sequence to the public brought the study of A. niger into the post-genomic era. Diverse omic data are being produced massively and rapidly, which largely upgrades our understanding to the hyperproduction mechanism of A. niger to a systems and molecular level. At meanwhile, its genetic operating system is becoming mature, which enables genome-scale genetic perturbation within A. niger. In conclusion, we are on the right way to redesign and engineer A. niger to an omnipotent cellular factory.
Aspergillus niger ; genetics ; metabolism ; Biotechnology ; methods ; Enzymes ; genetics ; secretion ; Gene Expression Regulation, Fungal ; Genes, Fungal ; Genome, Fungal ; Protein Biosynthesis ; genetics ; Recombinant Proteins ; secretion ; Transcription, Genetic

OBJECTIVETo investigate the application of differential display-2PCR(DD-PCR) in research on gene expression of Candida.

METHODSResistance to fluconazole was induced in a Candida albicans isolate 435 from vagina by culturing in YEPD broth with increasing fluconazole concentration in vitro, and the resistant isolate 435-2 (MIC=128 microg/ml ) was obtained after 80 days of incubation. Comparisons between 435 and 435-2 either in fluconazole-containing medium or in drug-free medium were performed with the modified DD-PCR including amplification with long primers, silver staining, reverse dot blot and non-radiographic labeling techniques.

RESULTSThree differential displayed bands were found which showed high homology to alcohol dehydrogenase 1 (ADH1), TOP2 and CDR1, respectively. The up-regulating expression of ADH1 and CDR1 associated with fluconazole resistance was further identified by RT-PCR.

CONCLUSIONThe up-regulating expression of ADH1 and CDR1 was associated with fluconazole resistance in Candida albicans, ADH1 might be a candidate of novel fluconazole resistant gene.

Antifungal Agents ; pharmacology ; Candida albicans ; drug effects ; genetics ; Drug Resistance, Fungal ; genetics ; Fluconazole ; pharmacology ; Fungal Proteins ; genetics ; Membrane Transport Proteins ; genetics ; Oxidoreductases ; genetics ; Polymerase Chain Reaction ; methods

BACKGROUNDCandida albicans is the most frequently seen opportunistic human fungal pathogen. Terbinafine is an allylamine antifungal agent that has been proven to have high clinical efficacy in the therapy of fungal infections, the mechanism of action of terbinafine involves the specific inhibition of fungal squalene epoxidase, resulting in ergosterol deficiency and accumulation of intracellular squalene. We used cDNA microarray analysis technology to monitor global expression profile changes of Candida albicans genes in response to terbinafine treatment, and we anticipated a panoramic view of the responses of Candida albicans cells to the representatives of allylamine antifungal agents at the molecular level in an effort to identify drug class-specific and mechanism-independent changes in gene expression.

METHODSCandida albicans strain ATCC 90028 was exposed to either medium alone or terbinafine at a concentration equivalent to the 1/2 minimal inhibitory concentrations (MICs, 4 mg/L) for 90 minutes. RNA was isolated and gene expression profiles were compared to identify the changes in the gene expression profile using a cDNA microarray analysis. Differential expression of 10 select genes detected by cDNA microarray analysis was confirmed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSA total of 222 genes were found to be responsive to terbinafine, including 121 up-regulated genes and 101 down-regulated genes. These included genes encoding membrane transport proteins belonging to the members of the ATP-binding cassette (ABC) or major facilitator superfamily (MFS; CDR1, AGP2, GAP6, PHO84, HOL3, FCY23, VCX1), genes involved in stress response and detoxification (CDR1, AGP2, HOL3), and gene involved in the ergosterol biosynthesis pathway (ERG12). The results of semi-quantitative RT-PCR were consistent with that of the cDNA microarray analysis.

CONCLUSIONSThe up-regulation of the gene encoding the multidrug resistance efflux pump CDR1 may contribute to the terbinafine resistance in Candida albicans. However, the precise roles of other affected genes remain unclear, further studies of these genes and their respective products that play roles in the context of antifungal resistance are warranted.

Antifungal Agents ; pharmacology ; Candida albicans ; drug effects ; genetics ; Ergosterol ; biosynthesis ; Fungal Proteins ; genetics ; Gene Expression Profiling ; Genome, Fungal ; Membrane Transport Proteins ; genetics ; Naphthalenes ; pharmacology ; Oligonucleotide Array Sequence Analysis

In this study, peaT1 gene was subcloned into the Pichia pastoris expression vector pPIC9K, which contained both the methanol-inducible promoter and the transcription terminator of the AOX1 gene, resulting the plasmid pPIC9K-peaT1. The recombinant plasmid was linearized by Sal I or Bgl II and transformed into P. pastoris GS115 by electroporation method. Recombinant strain was screened by Minimal Dextrose Medium and further confirmed by PCR. The gene was in frame integrated into the Pichia genome through homologous recombination, resulting the recombinant strain. Regulated by the alpha-Factor, promoter of AOX1 gene and termination signal of yeast genomic, the recombinant protein was expressed and secreted into the supernatant. The SDS-PAGE analysis indicated that the apparent molecular weight of target protein was about 35 kD. Bioassay results showed that the inhibition rate of the expressed protein against TMV was 30.37%. The supernatant was collected and then purified by anion exchange chromatography. This protein can promote seedling growth of wheat obviously.
Alternaria ; genetics ; Fungal Proteins ; biosynthesis ; genetics ; pharmacology ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; Triticum ; drug effects ; growth & development

Breeding of robust industrial Saccharomyces cerevisiae strains with high ethanol tolerance is of great significance for efficient fuel ethanol production. Zinc finger proteins play important roles in gene transcription and translation, and exerting control on the regulation of multiple genes. The sequence and localization of the zinc finger motif can be designed and engineered, and the artificial zinc finger protein can be used to regulate celluar metabolism. Stress tolerance of microbial strains is related to multiple genes. Therefore, it is possible to use artificially-designed zinc finger proteins to breed stress tolerant strains. In this study, a library containing artificial zinc finger protein encoding genes was transformed into the model yeast strain S288c. A recombinant strain named M01 with improved ethanol tolerance was obtained. The plasmid in M01 was isolated, and then transformed into the industrial yeast strain Sc4126. Ethanol tolerance of the recombinant strain of Sc4126 were significantly improved. When high gravity ethanol fermentation using 250 g/L glucose was performed, comparing with the wild-type strain, fermentation time of the recombinant strain was decreased by 24 h and the final ethanol concentration was enhanced by 6.3%. The results of this study demonstrate that artificial zinc finger proteins are able to exert control on stress tolerance of yeast strains, and these results provide basis to construct robust industrial yeast strains for efficient ethanol fermentation.
Adaptation, Physiological ; drug effects ; Drug Resistance, Fungal ; genetics ; Ethanol ; pharmacology ; Fungal Proteins ; genetics ; metabolism ; Industrial Microbiology ; Mutation ; genetics ; Peptide Library ; Saccharomyces cerevisiae ; genetics ; growth & development ; Zinc Fingers

OBJECTIVETo establish real-time PCR and loop-mediated isothermal amplification (LAMP) systems for detecting Cryptococcus neoformans CAP10 gene.

METHODSSpecific primers were designed targeting CAP10 gene of Cryptococcus neoformans, and the plasmid was constructed. After optimization of the reaction condition, the plasmid was quantitatively detected using real-time PCR and LAMP, and the detection sensitivity and specificity were evaluated. Clinical samples were also detected using the two methods.

RESULTSThe detection sensitivity of real-time PCR and LAMP was 6.8×10(1) and 6.8×10(3) copies, respectively. Real-time PCR yielded a higher positivity rate than LAMP. Both of the two methods showed a high detection specificity and produced negative results in the detection of Neisseria meningitidis, Candida albicans, Candida tropicalis, Aspergillus flavus, Aspergillus niger and Escherichia coli.

CONCLUSIONReal-time PCR is highly sensitive and specific for detecting Cryptococcus neoformans CAP10 gene but requires sophisticated equipment. LAMP, though with a relatively lower sensitivity, is simple to operate without the need of special equipment, and the result can be conveniently observed. Both of the two methods are suitable for detecting Cryptococcus neoformans and evaluating the treatment outcomes.

Cryptococcus neoformans ; genetics ; Fungal Proteins ; genetics ; Nucleic Acid Amplification Techniques ; methods ; Plasmids ; RNA, Fungal ; genetics ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

BACKGROUNDGlucocorticoid is speculated to be able to have Aspergillus fumigatus (A. fumigatus) being more susceptible to reactive oxygen species (ROS) by inhibiting Afyap1, the transcription factor activating protein-1 (AP-1) homologue in A. fumigatus, which may provide a clue to expand the clinical use of glucocorticoid in patients with fungal infections. In this study, we used dexamethasone to determine the direct effect on oxidative killing susceptibility of A. fumigatus in vitro, as well as the expression level of Afyap1 gene and its target genes (catalase and superoxide dismutase (SOD) genes).

METHODSA. fumigatus spores were treated with different concentrations (0, 0.02, 0.2 mg/ml) of glucocorticoids and assigned to four groups (A: 0.5 hour, B: 2 hours, C: 7 hours, D: 16 hours) according to the time of treatment. The H2O2 oxidative killing assay was done, using the standard method-spot test, in each group of A. fumigatus. We measured the oxidative killing susceptibility as well as the expression level of the gene Afyap1, CATA, SOD1 and SOD2 in A. fumigatus at each group. The antifungal susceptibility to itraconazole and amphotericin B in each group of A. fumigatus was also measured with M38-A2 method.

RESULTSThe oxidative killing susceptibility of A. fumigatus was increased, consistent with the reduction of Afyap1, CATA, SOD1 and SOD2 gene expression level after being treated with dexamethasone for 0.5 hours. However, these observations were disappeared along with being treated for longer time. The antifungal susceptibility to itraconazole and amphotericin B in the A. fumigatus strains treated with dexamethasone indicated no change, compared with those without dexamethasone treatment.

CONCLUSIONDexamethasone can have A. fumigatus being more susceptible to ROS when treated for shorter period (0.5 to 2 hours) via the reduction of Afyap1 gene expression as well as the down-stream enzyme-coding gene expression.

Aspergillus fumigatus ; drug effects ; genetics ; metabolism ; Dexamethasone ; pharmacology ; Fungal Proteins ; genetics ; metabolism ; Hydrogen Peroxide ; pharmacology

The Spt-Ada-Gcn5-acetyltransferase (SAGA) is an ancillary transcription initiation complex which is highly conserved. The ADA1 (alteration/deficiency in activation 1, also called histone H2A functional interactor 1, HFI1) is a subunit in the core module of the SAGA protein complex. ADA1 plays an important role in plant growth and development as well as stress resistance. In this paper, we performed genome-wide identification of banana ADA1 gene family members based on banana genomic data, and analyzed the basic physicochemical properties, evolutionary relationships, selection pressure, promoter cis-acting elements, and its expression profiles under biotic and abiotic stresses. The results showed that there were 10, 6, and 7 family members in Musa acuminata, Musa balbisiana and Musa itinerans. The members were all unstable and hydrophilic proteins, and only contained the conservative SAGA-Tad1 domain. Both MaADA1 and MbADA1 have interactive relationship with Sgf11 (SAGA-associated factor 11) of core module in SAGA. Phylogenetic analysis revealed that banana ADA1 gene family members could be divided into 3 classes. The evolution of ADA1 gene family members was mostly influenced by purifying selection. There were large differences among the gene structure of banana ADA1 gene family members. ADA1 gene family members contained plenty of hormonal elements. MaADA1-1 may play a prominent role in the resistance of banana to cold stress, while MaADA1 may respond to the Panama disease of banana. In conclusion, this study suggested ADA1 gene family members are highly conserved in banana, and may respond to biotic and abiotic stress.
Musa/genetics* ; Phylogeny ; Fungal Proteins ; Cell Nucleus ; Histones ; Stress, Physiological/genetics*

Fungi immunoregulatory proteins family is effective in immunological regulation and anti-tumor. We used Pichia pastoris expression system for recombinant expression of Lz-8, an immunomodulatory protein isolated from fruiting body of Ganoderma lucidum. The Gs115 (mut+) strains of P. pastoris was used as host cells. PCR and sequencing of DNA showed that Lz-8 cDNA was successfully integrated into the P. pastoris genome. Electrophoresis (SDS-PAGE), matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) and immunological techniques were used to identify recombinant Lz-8 (rLz-8). Lz-8 expressed in Escherichia coli, the Pichia system requires further optimization to obtain more active fungi immunomodulatory protein. Lz-8 was expressed in P. pastoris successfully, and polyacrylamide gel electrophoresis in the presence of SDS-PAGE gave a single band with an apparent Mr=14,000 D. MALDI-TOF-MS also showed that molecular weight of rLz-8 was 12,722 D. Aggregation was observed from sheep red blood cells in the presence of purified rLz-8 within the concentration range of 12.5-50 microg/mL. However, no aggregation was seen at concentration greater than 50 microg/mL for any type of human red blood cell. The dose at 0.5 mg/kg of rLz-8 induced macrophage cytophagocytesis, and set interferon as control at 0.5 mg/kg. These results suggested that active and stable rLz-8 was obtained in P. pastoris expression system.
Fungal Proteins ; biosynthesis ; genetics ; immunology ; Immunocompetence ; immunology ; Macrophages ; immunology ; Phagocytosis ; drug effects ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; immunology