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Curr Genet ; 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001274


The amino acid biosynthetic pathway of invasive pathogenic fungi has been studied as a potential antifungal drug target. Studies of the disruption of genes involved in amino acid biosynthesis have demonstrated the importance of this pathway in the virulence of Cryptococcus neoformans. Here, we identified the MET5 (CNL05500) and MET10 (CNG03990) genes in this pathway, both encoding sulfite reductase, which catalyzes the reduction of sulfite to sulfide. The MET14 (CNE03880) gene was also identified, which is responsible for the conversion of sulfate to sulfite. The use of cysteine as a sulfur source led to the production of methionine via hydrogen sulfide synthesis mediated by CYS4 (CNA06170), CYS3 (CNN01730), and MST1 (CND03690). MST1 exhibited high homology with the TUM1 gene of Saccharomyces cerevisiae, which has functional similarity with the 3-mercaptopyruvate sulfurtransferase (3-MST) gene in humans. Although the hypothesis that hydrogen sulfide is produced from cysteine via CYS4, CYS3, and MST1 warrants further study, the new insight into the metabolic pathway of sulfur-containing amino acids in C. neoformans provided here indicates the usefulness of this system in the development of screening tools for antifungal drug agents.

Int J Syst Evol Microbiol ; 70(2): 1158-1165, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31833830


Two yeast strains isolated from soil collected in Hokkaido, Japan, were found to secrete two extracellular lipases that exhibited activities at both 25 and 4 °C. Both strains could utilize olive oil, rapeseed oil, lard and fish oil as sole carbon sources. The similarity of the D1/D2 domain of the large subunit ribosomal RNA (LSU rRNA) sequence of these yeast strains to that of other yeasts in the GenBank database was very low (<96 %). The phylogenetic trees based on the LSU rRNA sequences and translation elongation factor-1-α (tef1-α) sequences indicated that both strains represented a member of the Wickerhamomyces /Candida clade. Sexual reproduction was not observed. The name Wickerhamomyces psychrolipolyticus f.a., sp. nov is proposed for this newly described yeast species producing cold-active lipases. This novel species is distinguishable from the type strains of other related species, Wickerhamomyces alni, Candida ulmi and Candida quercuum due to their abilities to grow at 4 to 30 °C, to produce lipase that is active also at 4 °C and to assimilate soluble starch.

Filogenia , Saccharomycetales/classificação , Microbiologia do Solo , Composição de Bases , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Japão , Lipase , Técnicas de Tipagem Micológica , Fator 1 de Elongação de Peptídeos/genética , Subunidades Ribossômicas Maiores/genética , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNA , Temperatura
Gan To Kagaku Ryoho ; 45(13): 2220-2222, 2018 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-30692337


A 61-year-old woman was referred to our hospital because of epigastric pain during chemotherapy for breast cancer recurrence. She was diagnosed with left breast cancer and underwent mastectomy with axillary lymph node dissection 13 years previously. The postoperative pathological examination result was luminal invasive lobular carcinoma. Hydronephrosis appeared after 1 month, which we diagnosed as ureter stenosis caused by radiation therapy for the lumbar metastasis and thus inserted an ureteralstent. After 1 month, computed tomography demonstrated expansion of the tumor into the stomach and duodenum. Upper gastrointestinalendoscopy demonstrated stenosis of the duodenum with intact mucosa. We diagnosed the duodenalstenosis due to the retroperitonealmetastasis of breast cancer and inserted duodenal, biliary, and pancreatic duct stents. The plural stent insertion was effective, and chemotherapy was administered with enforcement possibility for 7 months afterward.

Neoplasias da Mama , Carcinoma Lobular , Neoplasias Retroperitoneais , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Mastectomia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasias Retroperitoneais/secundário , Neoplasias Retroperitoneais/cirurgia , Stents
New Phytol ; 217(3): 1042-1049, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29194635


Plant cell surface receptor-like kinases (RLKs) mediate the signals from microbe-associated molecular patterns (MAMPs) that induce immune responses. Lipopolysaccharide (LPS), the major constituent of the outer membrane of gram-negative bacteria, is a common MAMP perceived by animals and plants; however, the plant receptors/co-receptors are unknown except for LORE, a bulb-type lectin S-domain RLK (B-lectin SD1-RLK) in Arabidopsis. OsCERK1 is a multifunctional RLK in rice that contains lysin motifs (LysMs) and is essential for the perception of chitin, a fungal MAMP, and peptidoglycan, a bacterial MAMP. Here, we analyzed the relevance of OsCERK1 to LPS perception in rice. Using OsCERK1-knockout mutants (oscerk1), we evaluated hydrogen peroxide (H2 O2 ) production and gene expression after LPS treatment. We also examined the LPS response in knockout mutants for the B-lectin SD1-RLK genes in rice and for all LysM-protein genes in Arabidopsis. Compared with wild-type rice cells, LPS responses in oscerk1 cells were mostly diminished. By contrast, rice lines mutated in either of three B-lectin SD1-RLK genes and Arabidopsis lines mutated in the LysM-protein genes responded normally to LPS. From these results, we conclude that OsCERK1 is an LPS receptor/co-receptor and that the LPS perception systems of rice and Arabidopsis are significantly different.

Lipopolissacarídeos/farmacologia , Oryza/imunologia , Imunidade Vegetal/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mutação/genética , Oryza/efeitos dos fármacos , Células Vegetais/efeitos dos fármacos , Células Vegetais/metabolismo , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo
J Exp Bot ; 58(8): 1957-67, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17452753


The aerial surfaces of the common or crystalline ice plant Mesembryanthemum crystallinum L., a halophytic, facultative crassulacean acid metabolism species, are covered with specialized trichome cells called epidermal bladder cells (EBCs). EBCs are thought to serve as a peripheral salinity and/or water storage organ to improve survival under high salinity or water deficit stress conditions. However, the exact contribution of EBCs to salt tolerance in the ice plant remains poorly understood. An M. crystallinum mutant lacking EBCs was isolated from plant collections mutagenized by fast neutron irradiation. Light and electron microscopy revealed that mutant plants lacked EBCs on all surfaces of leaves and stems. Dry weight gain of aerial parts of the mutant was almost half that of wild-type plants after 3 weeks of growth at 400 mM NaCl. The EBC mutant also showed reduced leaf succulence and leaf and stem water contents compared with wild-type plants. Aerial tissues of wild-type plants had approximately 1.5-fold higher Na(+) and Cl(-) content than the mutant grown under 400 mM NaCl for 2 weeks. Na(+) and Cl(-) partitioning into EBCs of wild-type plants resulted in lower concentrations of these ions in photosynthetically active leaf tissues than in leaves of the EBC-less mutant, particularly under conditions of high salt stress. Potassium, nitrate, and phosphate ion content decreased with incorporation of NaCl into tissues in both the wild type and the mutant, but the ratios of Na(+)/K(+) and Cl(-)/NO(3)(-)content were maintained only in the leaf and stem tissues of wild-type plants. The EBC mutant showed significant impairment in plant productivity under salt stress as evaluated by seed pod and seed number and average seed weight. These results clearly show that EBCs contribute to succulence by serving as a water storage reservoir and to salt tolerance by maintaining ion sequestration and homeostasis within photosynthetically active tissues of M. crystallinum.

Mesembryanthemum/metabolismo , Cloreto de Sódio/metabolismo , Homeostase , Mesembryanthemum/citologia , Mesembryanthemum/genética , Mutação , Nitratos/metabolismo , Fenótipo , Fosfatos/metabolismo , Fotossíntese , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Caules de Planta/citologia , Caules de Planta/genética , Caules de Planta/metabolismo , Potássio/metabolismo , Reprodução , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo