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1.
Sci Rep ; 13(1): 4285, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36922566

RESUMEN

Conidiation is an important reproductive process in Aspergillus. We previously reported, in A. nidulans, that the deletion of a putative glycosyltransferase gene, rseA/cpsA, causes an increase in the production of extracellular hydrolases and a severe reduction in conidiation. The aim of this study was to obtain novel genetic factors involved in the repression of conidiation in the rseA deletion mutant. We isolated mutants in which the rseA deletion mutant conidiation defect is suppressed and performed a comparative genomic analysis of these mutants. A gene encoding a putative transcription factor was identified as the associated candidate causative gene. The candidate gene was designated as srdA (suppressor gene for the conidiation defect of the rseA deletion mutant). The conidiation efficiency of the rseAsrdA double-deletion mutant was increased. Introduction of wild-type srdA into the suppressor mutants caused a conidiation defect similar to that of the rseA deletion mutant. Notably, the conidiation efficiencies of the rseAsrdA double-deletion and srdA single-deletion mutants were higher than that of the wild-type strain. These results indicate that srdA is a novel genetic factor that strongly represses conidiation of the rseA deletion mutant, and a putative transcriptional regulator, SrdA is a negative regulator of conidiation in A. nidulans.


Asunto(s)
Aspergillus nidulans , Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Regulación Fúngica de la Expresión Génica , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Mutación , Factores de Transcripción/metabolismo , Esporas Fúngicas/genética , Esporas Fúngicas/metabolismo , Eliminación de Gen
2.
PLoS Genet ; 18(1): e1009965, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-35041649

RESUMEN

Aspergillus fumigatus causes a range of human and animal diseases collectively known as aspergillosis. A. fumigatus possesses and expresses a range of genetic determinants of virulence, which facilitate colonisation and disease progression, including the secretion of mycotoxins. Gliotoxin (GT) is the best studied A. fumigatus mycotoxin with a wide range of known toxic effects that impair human immune cell function. GT is also highly toxic to A. fumigatus and this fungus has evolved self-protection mechanisms that include (i) the GT efflux pump GliA, (ii) the GT neutralising enzyme GliT, and (iii) the negative regulation of GT biosynthesis by the bis-thiomethyltransferase GtmA. The transcription factor (TF) RglT is the main regulator of GliT and this GT protection mechanism also occurs in the non-GT producing fungus A. nidulans. However, the A. nidulans genome does not encode GtmA and GliA. This work aimed at analysing the transcriptional response to exogenous GT in A. fumigatus and A. nidulans, two distantly related Aspergillus species, and to identify additional components required for GT protection. RNA-sequencing shows a highly different transcriptional response to exogenous GT with the RglT-dependent regulon also significantly differing between A. fumigatus and A. nidulans. However, we were able to observe homologs whose expression pattern was similar in both species (43 RglT-independent and 11 RglT-dependent). Based on this approach, we identified a novel RglT-dependent methyltranferase, MtrA, involved in GT protection. Taking into consideration the occurrence of RglT-independent modulated genes, we screened an A. fumigatus deletion library of 484 transcription factors (TFs) for sensitivity to GT and identified 15 TFs important for GT self-protection. Of these, the TF KojR, which is essential for kojic acid biosynthesis in Aspergillus oryzae, was also essential for virulence and GT biosynthesis in A. fumigatus, and for GT protection in A. fumigatus, A. nidulans, and A. oryzae. KojR regulates rglT, gliT, gliJ expression and sulfur metabolism in Aspergillus species. Together, this study identified conserved components required for GT protection in Aspergillus species.


Asunto(s)
Aspergillus/crecimiento & desarrollo , Gliotoxina/farmacología , Metiltransferasas/genética , Factores de Transcripción/genética , Aspergillus/efectos de los fármacos , Aspergillus/genética , Aspergillus fumigatus/efectos de los fármacos , Aspergillus fumigatus/genética , Aspergillus fumigatus/crecimiento & desarrollo , Aspergillus nidulans/efectos de los fármacos , Aspergillus nidulans/genética , Aspergillus nidulans/crecimiento & desarrollo , Aspergillus oryzae/efectos de los fármacos , Aspergillus oryzae/genética , Aspergillus oryzae/crecimiento & desarrollo , Proteínas Fúngicas/genética , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Gliotoxina/biosíntesis , RNA-Seq
3.
J Biosci Bioeng ; 131(6): 589-598, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33827772

RESUMEN

Koji molds, such as Aspergillus oryzae and Aspergillus sojae, are used in the food industry in East Asia and have been explored for the large-scale production of extracellular hydrolases. We previously found that the deletion of a gene encoding a putative GT2 glycosyltransferase increased production of extracellular hydrolases in A. sojae. The gene was named rseA (regulator of the secretory enzyme A). We predicted that intracellular signaling pathways were involved in the increased production of hydrolases in the ΔrseA mutant of A. sojae. However, little has been reported on molecular biological knowledge about A. sojae. Hence, Aspergillus nidulans, a typical model organism used in molecular biology, was employed for the functional characterization of rseA in this study. Deletion of the rseA ortholog in A. nidulans induced increased extracellular production of hydrolases under the solid-state cultivation condition, similar to that in A. sojae. The involvement of the cell wall integrity pathway and the high osmolarity glycerol pathway in ΔrseA was further investigated. The results indicated that the HOG pathway played an important role in the increased extracellular production of hydrolases caused by the deletion of the rseA gene. rseA ortholog in A. nidulans was identical to cpsA, which was reported to function as a regulator of mycotoxin production, morphogenesis, and cell wall biosynthesis. However, this is the first study reporting that rseA/cpsA regulates extracellular hydrolase production in A. nidulans.


Asunto(s)
Aspergillus nidulans/genética , Glicerol/metabolismo , Glicosiltransferasas/genética , Hidrolasas/metabolismo , Aspergillus/enzimología , Aspergillus/genética , Aspergillus nidulans/metabolismo , Pared Celular/metabolismo , Medios de Cultivo/química , Espacio Extracelular/enzimología , Espacio Extracelular/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Eliminación de Gen , Glicosiltransferasas/metabolismo , Hidrolasas/genética , Ingeniería Metabólica/métodos , Redes y Vías Metabólicas/genética , Técnicas Microbiológicas , Organismos Modificados Genéticamente , Concentración Osmolar , Vías Secretoras/genética
4.
Chembiochem ; 22(1): 203-211, 2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-32885554

RESUMEN

The filamentous fungus Aspergillus oryzae has 27 putative iterative type I polyketide synthase (PKS) gene clusters, but the secondary metabolites produced by them are mostly unknown. Here, we focused on eight clusters that were reported to be expressed at relatively high levels in a transcriptome analysis. By comparing metabolites between an octuple-deletion mutant of these eight PKS gene clusters and its parent strain, we found that A. oryzae produced 2,4'-dihydroxy-3'-methoxypropiophenone (1) and its precursor, 4'-hydroxy-3'-methoxypropiophenone (3) in a specific liquid medium. Furthermore, an iterative type I PKS (PpsB) encoded by AO090102000166 and an acetyl-CoA ligase (PpsA) encoded downstream from ppsB were shown to be essential for their biosynthesis. PpsC, encoded upstream from ppsB, was shown to have 3-binding activity (Kd =26.0±6.2 µM) and is suggested to be involved in the conversion of 3 to 1. This study deepens our understanding of cryptic secondary metabolism in A. oryzae.


Asunto(s)
Aspergillus oryzae/genética , Sintasas Poliquetidas/genética , Aspergillus oryzae/metabolismo , Estructura Molecular , Sintasas Poliquetidas/metabolismo
5.
J Biosci Bioeng ; 130(5): 480-488, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32800811

RESUMEN

Free dihomo-γ-linolenic acid (DGLA), a polyunsaturated free fatty acid (FFA), is a precursor of the eicosanoid prostaglandin E1 and is expected to be a source material for artificial production. We previously constructed the Aspergillus oryzae mutant strain ARA1 that produced free DGLA from the disruptant of faaA, an acyl-CoA synthetase gene, where FFA productivity increased by 9.2-fold compared with that of the wild-type strain. Here, we aimed to achieve enhancement of free DGLA productivity. Because saturated FFAs, such as palmitic acid and stearic acid, accounted for about 45% and 25% of total FFAs produced by ARA1, respectively, we used a strategy to facilitate elongation and desaturation of these FFAs to oleic acid and linoleic acid by overexpressing genes encoding elongase, Δ9-desaturase, and Δ12-desaturase originally expressed in A. oryzae. Ten genes were predicted to encode desaturases, and their overexpression DNA constructs were introduced into ARA1. AO090001000224 and AO090011000488 facilitated Δ12-desaturation and Δ9-desaturation most, respectively, following overexpression. Next, ARA1 strain was modified to DGLA1cre strain for producing free DGLA as a final product, and co-overexpression of these two desaturase genes was then introduced to DGLA1cre. Moreover, single overexpression of two genes predicted to encode elongases was additionally introduced, and only AO090003000572 facilitated elongation. Consequently, in the co-overexpression mutant of AO090001000224, AO090011000488, and AO090003000572, free DGLA content ratio increased by 1.8-fold from ARA1 to 14.5%, and the productivity also increased by 1.8-fold to 0.086 mmol/g-dry-cell-weight. The yield was 284 mg/L. These findings provided insights into strategies for improving microbial production of polyunsaturated FFAs.


Asunto(s)
Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Ácido Graso Desaturasas/genética , Elongasas de Ácidos Grasos/genética , Ácido Linoleico/química , Ácido Linoleico/metabolismo , Expresión Génica , Ingeniería Genética
6.
J Gen Appl Microbiol ; 66(3): 195-199, 2020 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-31776294

RESUMEN

We recently developed an Aspergillus oryzae strain in which malonyl-coenzyme A (CoA) supply is strengthened by the deletion of snfA and SCAP as an efficient host to produce a plant polyketide, curcumin. Here, we examined the effectiveness of this strain in producing another polyketide, atrochrysone carboxylic acid (ACA), which is synthesized from eight molecules of malonyl-CoA using an iterative type I polyketide synthase, ACA synthase (ACAS), and atrochrysone carboxyl ACP thioesterase (ACTE) in Aspergillus terreus. When ACAS and ACTE were introduced, the A. oryzae ΔsnfAΔSCAP strain produced approximately four times more ACA-related polyketides than did the control strain expressing both genes. This result further demonstrated the availability of the A. oryzae ΔsnfAΔSCAP strain for heterologous polyketide production.


Asunto(s)
Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Malonil Coenzima A/metabolismo , Policétidos/metabolismo , Curcumina/metabolismo , Eliminación de Gen , Genes Fúngicos , Sintasas Poliquetidas/metabolismo
7.
Biosci Biotechnol Biochem ; 83(7): 1372-1381, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31023165

RESUMEN

The filamentous fungus Aspergillus oryzae was recently used as a heterologous host for fungal secondary metabolite production. Here, we aimed to produce the plant polyketide curcumin in A. oryzae. Curcumin is synthesized from feruloyl-coenzyme A (CoA) and malonyl-CoA by curcuminoid synthase (CUS). A. oryzae expressing CUS produced curcumin (64 µg/plate) on an agar medium containing feruloyl-N-acetylcysteamine (a feruloyl-CoA analog). To increase curcumin yield, we attempted to strengthen the supply of malonyl-CoA using two approaches: enhancement of the reaction catalyzed by acetyl-CoA carboxylase (ACC), which produces malonyl-CoA from acetyl-CoA, and inactivation of the acetyl-CoA-consuming sterol biosynthesis pathway. Finally, we succeeded in increasing curcumin yield sixfold by the double disruption of snfA and SCAP; SnfA is a homolog of SNF1, which inhibits ACC activity by phosphorylation in Saccharomyces cerevisiae and SCAP is positively related to sterol biosynthesis in Aspergillus terreus. This study provided useful information for heterologous polyketide production in A. oryzae.


Asunto(s)
Aspergillus oryzae/metabolismo , Curcumina/metabolismo , Malonil Coenzima A/metabolismo , Catálisis , Fosforilación , Saccharomyces cerevisiae/metabolismo
8.
Fungal Genet Biol ; 127: 35-44, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30790620

RESUMEN

Aspergillus oryzae is an important microorganism in the bio- and food industries; therefore, understanding the mechanism underlying its secondary metabolism regulation is important for ensuring its safe use. Here, we screened a novel Zn(II)2-Cys6-type protein-encoding gene, AO090003001186, designated as kpeA (kojic acid production enhancement A), from an A. oryzae disruption mutant library of transcriptional regulators. kpeA is highly conserved among filamentous fungi and encodes a protein with Zn(II)2-Cys6 motif located in the middle of the sequence. Phylogenetic analysis revealed that KpeA was classified into a distal group compared to other fungal Zn(II)2-Cys6-type transcriptional regulators. A Cys to Ala substitution mutant of KpeA showed identical phenotype to the kpeA disruption strain, confirming that KpeA is novel type Zn(II)2-Cys6 binding protein. Colonies of the kpeA disruption strain (ΔkpeA) had longer aerial hyphae and showed decreased conidia production. Microscopic analysis suggested that the reduced vesicle size and conidial head formation in ΔkpeA strain account for the decreased conidia production. Transcriptional levels of brlA and downstream abaA and wetA were decreased in ΔkpeA strain. Moreover, ΔkpeA strain produced 6-fold more kojic acid than the control strains, and the expression of kojR and kojA was increased in ΔkpeA strain. Therefore, KpeA is a novel Zn(II)2-Cys6-type protein likely involved in conidiation and kojic acid production at the transcriptional level.


Asunto(s)
Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Proteínas Fúngicas/genética , Pironas/metabolismo , Metabolismo Secundario , Esporas Fúngicas/crecimiento & desarrollo , Regulación Fúngica de la Expresión Génica , Biblioteca de Genes , Fenotipo , Esporas Fúngicas/genética , Zinc
9.
Appl Environ Microbiol ; 85(8)2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-30737353

RESUMEN

Basic-region helix-loop-helix (bHLH) proteins are a superfamily of transcription factors that are often involved in the control of growth and differentiation. Recently, it was reported that the bHLH transcription factor DevR is involved in both asexual and sexual development in Aspergillus nidulans and regulates the conidial melanin production in Aspergillus fumigatus In this study, we identified and characterized an Aspergillus oryzae gene that showed high similarity with devR of A. nidulans and A. fumigatus (AodevR). In the AodevR-disrupted strain, growth was delayed and the number of conidia was decreased on Czapek-Dox (CD) minimal agar plates, but the conidiation was partially recovered by adding 0.6 M KCl. Simultaneously, the overexpression of AodevR was induced and resulted in extremely poor growth when the carbon source changed from glucose to polysaccharide (dextrin) in the CD agar plate. Scanning electron microscopy (SEM) indicated that the overexpression of AodevR resulted in extremely thin aberrant hyphal morphology. Conversely, the deletion of AodevR resulted in thicker hyphae and in more resistance to Congo red relative to the control strain. Quantitative reverse transcriptase PCR (RT-PCR) further indicated that AoDevR significantly affects chitin and starch metabolism, and importantly, the overexpression of AodevR inhibited the expression of genes related to starch degradation. A yeast one-hybrid assay suggested that the DevR protein possibly interacted with the promoter of amyR, which encodes a transcription factor involved in amylase production. Importantly, AoDevR is involved in polysaccharide metabolism and affects the growth of the A. oryzae strain.IMPORTANCEAspergillus oryzae is an industrially important filamentous fungus; therefore, a clear understanding of its polysaccharide metabolism and utilization is very important for its industrial utilization. In this study, we revealed that the basic-region helix-loop-helix (bHLH) transcription factor AoDevR is importantly involved in chitin and starch metabolism in A. oryzae The overexpression of AodevR strongly suppressed the expression of amylase-related genes. The results of a yeast one-hybrid assay suggested that the DevR protein potentially interacts with the promoter of amyR, which encodes a transcription factor involved in amylase production and starch utilization. This study provides new insight for further revealing the regulation mechanism of amylase production in A. oryzae.


Asunto(s)
Aspergillus oryzae/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Metabolismo de los Hidratos de Carbono , Proteínas Fúngicas/metabolismo , Factores de Transcripción/metabolismo , Amilasas/biosíntesis , Amilasas/genética , Aspergillus oryzae/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Quitina/metabolismo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Hifa/citología , Hifa/metabolismo , Dominios y Motivos de Interacción de Proteínas , Esporas Fúngicas/crecimiento & desarrollo , Almidón/metabolismo , Factores de Transcripción/genética
10.
Biosci Biotechnol Biochem ; 83(8): 1506-1513, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30466366

RESUMEN

Heptelidic acid (HA), a sesquiterpene lactone, is a known inhibitor of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Recently, we found that HA was produced by Aspergillus oryzae RIB40 and acted as the growth inhibitor of the salt-tolerant lactic acid bacteria in soy sauce brewing. Although several decades have passed since the discovery of HA, the genes involved in its biosynthesis and biosynthetic pathway have not yet been fully identified. In this study, we identified the HA biosynthetic gene cluster (HA cluster) using gene disruption and expression analysis. We also revealed that two transcription regulatory genes adjacent to the HA cluster were responsible for the expression of HA biosynthetic genes in A. oryzae. Interestingly, the HA cluster contained a gene encoding GAPDH (gpdB), which showed much higher resistance to HA than the GAPDH gene (gpdA) located at the other locus, but which did not seem to act as a self-resistant gene.


Asunto(s)
Antibacterianos/metabolismo , Aspergillus oryzae/genética , Familia de Multigenes , Aspergillus oryzae/metabolismo , Genes Fúngicos , Gliceraldehído-3-Fosfato Deshidrogenasas/antagonistas & inhibidores , Sesquiterpenos/metabolismo
11.
Artículo en Inglés | MEDLINE | ID: mdl-30305913

RESUMEN

BACKGROUND: Translocated chromosomal duplications occur spontaneously in many organisms; segmental duplications of large chromosomal regions are expected to result in phenotypic changes because of gene dosage effects. Therefore, experimentally generated segmental duplications in targeted chromosomal regions can be used to study phenotypic changes and determine the functions of unknown genes in these regions. Previously, we performed tandem duplication of a targeted chromosomal segment in Aspergillus oryzae. However, in tandem chromosomal duplication, duplication of chromosomal ends and multiple chromosomal duplication are difficult. In this study, we aimed to generate fungal strains with a translocated duplication or triplication of a targeted chromosomal region via break-induced replication. RESULTS: Double-strand breaks were introduced into chromosomes of parental strains by treating protoplast cells with I-SceI meganuclease. Subsequently, strains were generated by nonreciprocal translocation of a 1.4-Mb duplicated region of chromosome 2 to the end of chromosome 4. Another strain, containing a triplicated region of chromosome 2, was generated by translocating a 1.4-Mb region of chromosome 2 onto the ends of chromosomes 4 and 7. Phenotypic analyses of the strains containing segmental duplication or triplication of chromosome 2 showed remarkable increases in protease and amylase activities in solid-state cultures. Protease activity was further increased in strains containing the duplication and triplication after overexpression of the transcriptional activator of proteases prtT. This indicates that the gene-dosage effect and resulting phenotypes of the duplicated chromosomal region were enhanced by multiple duplications, and by the combination of the structural gene and its regulatory genes. Gene expression analysis, conducted using oligonucleotide microarrays, showed increased transcription of a large population of genes located in duplicated or triplicated chromosomal regions. CONCLUSION: In this study, we performed translocated chromosomal duplications and triplications of a 1.4-Mb targeted region of chromosome 2. Strains containing a duplication of chromosome 2 showed significant increases in protease and amylase activities; these enzymatic activities were further increased in the strain containing a triplication of chromosome 2. This indicates that segmental duplications of chromosomes enhance gene-dosage effects, and that the resulting phenotypes play important phenotypic roles in A. oryzae.

12.
Biosci Biotechnol Biochem ; 82(8): 1437-1443, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29629630

RESUMEN

In soy sauce brewing, the results of the fermentation of lactic acid greatly affect the quality of soy sauce. The soy sauce moromi produced with Aspergillus oryzae RIB40 allows the growth of Tetragenococcus halophilus NBRC 12172 but not T. halophilus D10. We isolated and identified heptelidic acid (HA), an inhibitor of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), produced by A. oryzae RIB40 as the growth inhibitor of the salt-tolerant lactic acid bacteria. The growth inhibition of T. halophilus D10 by HA was suggested to be associated with the direct inhibition of GAPDH activity under high salt environment. The difference in the susceptibility to HA among various strains of T. halophilus was caused by the mutations in the gene encoding GAPDH.


Asunto(s)
Aspergillus oryzae/metabolismo , Ácido Láctico/metabolismo , Lactobacillales/crecimiento & desarrollo , Alimentos de Soja/microbiología , Secuencia de Aminoácidos , Aspergillus oryzae/enzimología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Fermentación , Industria de Alimentos , Gliceraldehído-3-Fosfato Deshidrogenasas/antagonistas & inhibidores , Gliceraldehído-3-Fosfato Deshidrogenasas/química , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Lactobacillales/efectos de los fármacos , Lactobacillales/fisiología , Pruebas de Sensibilidad Microbiana , Tolerancia a la Sal , Homología de Secuencia de Aminoácido , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/farmacología
13.
Curr Genet ; 64(6): 1245-1260, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29654355

RESUMEN

The paralogous transcription factors AraR and XlnR in Aspergillus regulate genes that are involved in degradation of cellulose and hemicellulose and catabolism of pentose. AraR and XlnR target the same genes for pentose catabolism but target different genes encoding enzymes for polysaccharide degradation. To uncover the relationship between these paralogous transcription factors, we examined their contribution to regulation of the PCP genes and compared their preferred recognition sequences. Both AraR and XlnR are involved in induction of all the pentose catabolic genes in A. oryzae except larA encoding L-arabinose reductase, which was regulated by AraR but not by XlnR. DNA-binding studies revealed that the recognition sequences of AraR and XlnR also differ only slightly; AraR prefers CGGDTAAW, while XlnR prefers CGGNTAAW. All the pentose catabolic genes possess at least one recognition site to which both AraR and XlnR can bind. Cooperative binding by the factors was not observed. Instead, they competed to bind to the shared sites. XlnR bound to the recognition sites mentioned above as a monomer, but bound to the sequence TTAGSCTAA on the xylanase promoters as a dimer. Consequently, AraR and XlnR have significantly similar, but not the same, DNA-binding properties. Such a slight difference in these paralogous transcription factors may lead to complex outputs in enzyme production depending on the concentrations of coexisting inducer molecules in the natural environment.


Asunto(s)
Aspergillus oryzae/metabolismo , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica/fisiología , Vía de Pentosa Fosfato/fisiología , Multimerización de Proteína/fisiología , Elementos de Respuesta , Transactivadores/metabolismo , Aspergillus oryzae/química , Aspergillus oryzae/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Transactivadores/química , Transactivadores/genética
15.
Appl Microbiol Biotechnol ; 102(1): 319-332, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29098410

RESUMEN

The helix-loop-helix (HLH) family of transcriptional factors is a key player in a wide range of developmental processes in organisms from mammals to microbes. We previously identified the bHLH transcription factor SclR in Aspergillus oryzae and found that the loss of SclR function led to significant phenotypic changes, such as rapid protein degradation and cell lysis in dextrin-polypeptone-yeast extract liquid medium. The result implied that SclR is potentially important in both traditional fermentative manufacturing and commercial enzyme production in A. oryzae because of its effect on growth. Therefore, this study presents a comparative assessment at the proteome level of the intracellular differences between an sclR-disrupted strain and a control strain using isobaric tandem mass tag (TMT) labeling for quantification. A total of 5447 proteins were identified, and 568 were differentially expressed proteins (DEPs). Of the DEPs, 251 proteins were increased by 1.5-fold, and 317 proteins were decreased by 1.5-fold in an sclR-disrupted strain compared to the control. The comparison of the quantitative TMT results revealed that SclR was mainly involved in carbon metabolism, especially carbohydrate metabolism. In addition, an enzyme profile by a semi-quantitative method (API-ZYM) indicated that three enzymes (ß-galactosidase, α-glucosidase, and α-mannosidase) were significantly less active in the ∆sclR strain than in the control. Moreover, quantitative RT-PCR showed that the expression of certain genes was changed similarly to their corresponding proteins. These results suggested that a possible function of SclR during growth of A. oryzae is its important involvement in carbohydrate metabolism.


Asunto(s)
Aspergillus oryzae/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Metabolismo de los Hidratos de Carbono , Proteínas Fúngicas/metabolismo , Proteómica , Aspergillus oryzae/enzimología , Aspergillus oryzae/genética , Aspergillus oryzae/crecimiento & desarrollo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Fermentación , Proteínas Fúngicas/genética , Proteoma , Reacción en Cadena en Tiempo Real de la Polimerasa , alfa-Glucosidasas/genética , alfa-Manosidasa/genética , beta-Galactosidasa/genética
16.
Genome Announc ; 5(7)2017 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-28209823

RESUMEN

The highly halotolerant and allopolyploid yeast Zygosaccharomyces rouxii is industrially used for the food production in high concentrations of salt, such as brewing soy sauce and miso paste. Here, we report the draft genome sequence of Z. rouxii NBRC 1876 isolated from miso paste.

17.
Mol Microbiol ; 102(5): 810-826, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27588830

RESUMEN

Fungal cellulolytic and hemicellulolytic enzymes are promising tools for industrial hydrolysis of cellulosic biomass; however, the regulatory network underlying their production is not well understood. The recent discovery of the transcriptional activators ClrB and McmA in Aspergillus nidulans implied a novel regulatory mechanism driven by their interaction, experimental evidence for which was obtained from transcriptional and DNA-binding analyses in this study. It was found that ClrB was essential for induced expression of all the genes examined in this study, while McmA dependency of their expression was gene-dependent. DNA-binding studies revealed McmA assisted in the recruitment of ClrB to the cellulose-responsive element (CeRE) in the promoters of eglA and eglB, expression of which was significantly reduced in the mcmA mutant. The CCG triplet within the CeRE served as the recognition sequence for the ClrB monomer. In contrast, ClrB did not require McmA for binding as a homodimer to the CGGN8 CCG sequences in the promoter of mndB, expression of which was affected less in the mcmA mutant than in all other examined genes. Thus, there are two types of ClrB-mediated regulation: McmA-assisted and McmA-independent. This novel McmA-ClrB synergistic system provides new insights into the complex regulatory network involved in cellulase and hemicellulase production.


Asunto(s)
Aspergillus nidulans/enzimología , Aspergillus nidulans/genética , Celulasa/genética , Glicósido Hidrolasas/genética , Celulasa/biosíntesis , Celulosa/metabolismo , Regulación Fúngica de la Expresión Génica , Glicósido Hidrolasas/biosíntesis , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Proteínas de Mantenimiento de Minicromosoma/genética , Proteínas de Mantenimiento de Minicromosoma/metabolismo , Regiones Promotoras Genéticas , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Activación Transcripcional
18.
Sci Rep ; 6: 32865, 2016 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-27628599

RESUMEN

Esterified drimane-type sesquiterpene lactones such as astellolides display various biological activities and are widely produced by plants and fungi. Given their low homology to known sesquiterpene cyclases, the genes responsible for their biosynthesis have not been uncovered yet. Here, we identified the astellolide gene cluster from Aspergillus oryzae and discovered a novel sesquiterpene biosynthetic machinery consisting of AstC, AstI, and AstK. All these enzymes are annotated as haloacid dehalogenase-like hydrolases, whereas AstC also contains a DxDTT motif conserved in class II diterpene cyclases. Based on enzyme reaction analyses, we found that AstC catalysed the protonation-initiated cyclisation of farnesyl pyrophosphate into drimanyl pyrophosphate. This was successively dephosphorylated by AstI and AstK to produce drim-8-ene-11-ol. Moreover, we also identified and characterised a unique non-ribosomal peptide synthetase, AstA, responsible for esterifying aryl acids to drimane-type sesquiterpene lactones. In this study, we highlight a new biosynthetic route for producing sesquiterpene and its esterified derivative. Our findings shed light on the identification of novel sesquiterpenes via genome mining.


Asunto(s)
Aspergillus oryzae/genética , Familia de Multigenes , Sesquiterpenos/metabolismo , Secuencias de Aminoácidos , Aspergillus oryzae/enzimología , Clonación Molecular , Perfilación de la Expresión Génica , Genes Fúngicos , Espectroscopía de Resonancia Magnética , Análisis de Secuencia por Matrices de Oligonucleótidos , Monoéster Fosfórico Hidrolasas/química , Fosforilación , Proteínas Recombinantes/metabolismo
19.
Appl Microbiol Biotechnol ; 100(13): 5859-68, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26960315

RESUMEN

Aspergillus oryzae produces a large amount of secreted proteins in solid-state culture, and some proteins such as glucoamylase (GlaB) and acid protease (PepA) are specifically produced in solid-state culture, but rarely in submerged culture. From the disruption mutant library of A. oryzae transcriptional regulators, we successfully identified a disruption mutant showing an extremely low production level of GlaB but a normal level of α-amylase production. This strain was a disruption mutant of the C2H2-type transcription factor, FlbC, which is reported to be involved in the regulation of conidiospore development. Disruption mutants of other upstream regulators comprising a conidiation regulatory network had no apparent effect on GlaB production in solid-state culture. In addition to GlaB, the production of acid protease in solid-state culture was also markedly decreased by flbC disruption. Northern blot analyses revealed that transcripts of glaB and pepA were significantly decreased in the flbC disruption strain. These results suggested that FlbC is involved in the transcriptional regulation of genes specifically expressed under solid-state cultivation conditions, possibly independent of the conidiation regulatory network.


Asunto(s)
Aspergillus oryzae/metabolismo , Proteínas Fúngicas/metabolismo , Regulación Enzimológica de la Expresión Génica , Glucano 1,4-alfa-Glucosidasa/genética , Péptido Hidrolasas/genética , Factores de Transcripción/metabolismo , Aspergillus oryzae/enzimología , Aspergillus oryzae/genética , Aspergillus oryzae/crecimiento & desarrollo , Medios de Cultivo/metabolismo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Glucano 1,4-alfa-Glucosidasa/metabolismo , Péptido Hidrolasas/metabolismo , Factores de Transcripción/genética
20.
J Antibiot (Tokyo) ; 69(1): 4-8, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26126743

RESUMEN

The filamentous fungus Aspergillus oryzae is an important industrial mold. Recent genomic analysis indicated that A. oryzae has a large number of biosynthetic genes for secondary metabolites (SMs), but many of the SMs they produce have not been identified. For better understanding of SMs production by A. oryzae, we screened a gene-disruption library of transcription factors including chromatin-remodeling factors and found two gene disruptions that show similarly altered SM production profiles. One is a homolog of Aspergillus nidulans cclA, a component of the histone 3 lysine 4 (H3K4) methyltransferase complex of proteins associated with Set1 complex, and the other, sppA, is an ortholog of Saccharomyces cerevisiae SPP1, another component of a complex of proteins associated with Set1 complex. The cclA and sppA disruptions in A. oryzae are deficient in trimethylation of H3K4. Furthermore, one of the SMs that increased in the cclA disruptant was identified as astellolide F (14-deacetyl astellolide B). These data indicate that both cclA and sppA affect production of SMs including astellolides by affecting the methylation status of H3K4 in A. oryzae.


Asunto(s)
Aspergillus oryzae/metabolismo , Ensamble y Desensamble de Cromatina/fisiología , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica/fisiología , Sesquiterpenos/metabolismo , Aspergillus oryzae/genética , Ensamble y Desensamble de Cromatina/genética , Proteínas Fúngicas/genética , Mutación , Sesquiterpenos Policíclicos , Sesquiterpenos/química
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