Effects of leader sequences upon the heterologous expression of restrictocin in Aspergillus nidulans and Aspergillus niger

1995 ◽  
Vol 41 (7) ◽  
pp. 601-611 ◽  
Author(s):  
Tristan Brandhorst ◽  
William R. Kenealy
Keyword(s):  
Aspergillus Niger ◽  
Heterologous Expression ◽  
Aspergillus Nidulans ◽  
Signal Sequence ◽  
Leader Sequence ◽  
Toxic Effects ◽  
Transcript Levels ◽  
Pro Region ◽  
Cellular Lysis

The effects of altered leader sequences on the secretion and localization of restrictocin expression in Aspergillus nidulans and Aspergillus niger were investigated. The region encoding the leader sequence of the Aspergillus resirictus restrictocin (res) gene was altered and variants were expressed under the glucoamylase (glaA) promoter in A. nidulans and A. niger. The entire restrictocin leader sequence was replaced by the glaA leader sequence in one variant. In another, the signal sequence of restrictocin was replaced with the glaA signal, leaving a hybrid with the putative restrictocin pro region in place of the glaA pro region. The putative pro region was deleted from the restrictocin leader of a third variant. Toxic effects, such as reduced transcript levels and cellular lysis, were minimal when restrictocin was expressed with the native leader sequence, but became more pronounced as the leader sequence was varied. These toxic effects were inversely proportional to the level of restrictocin secreted. In all transformed strains, restrictocin secretion appeared at the periphery of colonies and was observed to occur at the tips of hyphae. Localization of restrictocin to differentiated structures (conidiophores), as occurs in A. resirictus, was observed only in transformed strains containing the complete restrictocin leader sequence.Key words: localization, secretion, targeting, translocation, development.

Heterologous expression of the Aspergillus nidulans alcR–alcA system in Aspergillus niger

2002 ◽  
Vol 37 (1) ◽  
pp. 89-97 ◽  
Author(s):  
I Nikolaev ◽  
M Mathieu ◽  
P.J.I van de Vondervoort ◽  
J Visser ◽  
B Felenbok
Keyword(s):  
Aspergillus Niger ◽  
Heterologous Expression ◽  
Aspergillus Nidulans

Cloning of a gar (Lepisosteus osseus) GH cDNA: trends in actinopterygian GH structure

1996 ◽  
Vol 16 (1) ◽  
pp. 73-80 ◽  
Author(s):  
D A Rubin ◽  
J H Youson ◽  
L E Marra ◽  
R M Dores
Keyword(s):  
Cdna Library ◽  
Untranslated Region ◽  
Signal Sequence ◽  
Leader Sequence ◽  
Open Reading Frame ◽  
Russian Sturgeon ◽  
Reading Frame ◽  
Terminal Codon

ABSTRACT A cDNA containing the sequence of GH was cloned and sequenced from a pituitary cDNA library for the holostean fish Lepisosteus osseus (common name: gar). The gar GH cDNA contained an open reading frame of 633 nucleotides and a 3′ untranslated region (including the terminal codon TAG) of 1058 nucleotides. The overall length of the gar GH cDNA including leader sequence, signal sequence, hormone sequence and 3′ untranslated region was 1713 nucleotides. Thus, the gar GH cDNA is the largest vertebrate GH cDNA yet cloned. A comparison of GH sequences from ancient (holostean fishes — gar and bowfin; one chondrostean fish — the Russian sturgeon) and more modern (27 species of teleosts) members of class Actinopterygii indicate that members of this class have maintained many of the invariant residues deemed necessary for GH folding motifs (intramolecular relationships) observed in mammals.

scholarly journals عزل وتعريف واختبار كفاءة بعض الفطريات في تحلل الهيدروكربون من التربة الملوثة بالنفط

2020 ◽  
Vol 3 (1) ◽  
pp. 78-90
Author(s):  
سعاد محمد خليفة أبوالغيث ◽  
أحلام القمودي محمد زعيط
Keyword(s):  
Aspergillus Niger ◽  
Aspergillus Fumigatus ◽  
Aspergillus Nidulans ◽  
Aspergillus Flavus ◽  
Malt Extract Agar ◽  
Malt Extract ◽  
Extract Agar

استهدفت هذه الدراسة عزل بعض أنواع الفطريات من التربة الملوثة بالهيدروكربون بمصفاة الزاوية لتكرير النفط، حيث تم عزل وتعريف بعض الفطريات مثل Rhizopus, Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Aspergillus nidulans وأوضحت نتائج هذه الدراسة أن تواجد وتنوع فطر Aspergillus قد تفوق معنويا مقارنة بتواجد وتنوع فطرRhizopus. كما تم في هذه الدراسة اختبار قدرة وكفاءة الفطريات المعزولة على النمو واستغلال المركبات الهيدروكربونية المتمثلة في زيت الحمادة وزيت الشرارة بتركيز 1% و3%، حيث أوضحت النتائج بأن جنس Rhizopus سجل أعلى معدل للنمو على الوسط الغذائي Malt Extract Agar، وسجل كلا من فطر A. fumigatus وفطر A. flavus معدّل النمو القطري أعلى معنويا من النمو القطري لفطرA. niger  وفطر A. nidulans. هذه المعدّلات العالية تدل على إمكانية استخدام الفطريات المعزولة في المعالجة البيولوجية للتربة الملوّثة بالنفط.

scholarly journals The Lipomyces starkeyi gene Ls120451 encodes a cellobiose transporter that enables cellobiose fermentation in Saccharomyces cerevisiae

2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Jorg C de Ruijter ◽  
Kiyohiko Igarashi ◽  
Merja Penttilä
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Aspergillus Niger ◽  
Heterologous Expression ◽  
In Silico ◽  
Penicillium Oxalicum ◽  
Microbial Fermentation ◽  
Lipomyces Starkeyi ◽  
Yeast Saccharomyces Cerevisiae ◽  
Sugar Transporters ◽  
Selection Of

ABSTRACT Processed lignocellulosic biomass is a source of mixed sugars that can be used for microbial fermentation into fuels or higher value products, like chemicals. Previously, the yeast Saccharomyces cerevisiae was engineered to utilize its cellodextrins through the heterologous expression of sugar transporters together with an intracellular expressed β-glucosidase. In this study, we screened a selection of eight (putative) cellodextrin transporters from different yeast and fungal hosts in order to extend the catalogue of available cellobiose transporters for cellobiose fermentation in S. cerevisiae. We confirmed that several in silico predicted cellodextrin transporters from Aspergillus niger were capable of transporting cellobiose with low affinity. In addition, we found a novel cellobiose transporter from the yeast Lipomyces starkeyi, encoded by the gene Ls120451. This transporter allowed efficient growth on cellobiose, while it also grew on glucose and lactose, but not cellotriose nor cellotetraose. We characterized the transporter more in-depth together with the transporter CdtG from Penicillium oxalicum. CdtG showed to be slightly more efficient in cellobiose consumption than Ls120451 at concentrations below 1.0 g/L. Ls120451 was more efficient in cellobiose consumption at higher concentrations and strains expressing this transporter grew slightly slower, but produced up to 30% more ethanol than CdtG.

Thaumatin Production in Aspergillus awamori by Use of Expression Cassettes with Strong Fungal Promoters and High Gene Dosage

1999 ◽  
Vol 65 (3) ◽  
pp. 1168-1174 ◽  
Author(s):  
Francisco-Jose Moralejo ◽  
Rosa-Elena Cardoza ◽  
Santiago Gutierrez ◽  
Juan F. Martin
Keyword(s):  
Protein Translocation ◽  
Gene Dosage ◽  
Signal Sequence ◽  
Aspergillus Awamori ◽  
Recognition Sequence ◽  
Transcript Levels ◽  
Sweet Protein ◽  
High Gene ◽  
Protease Deficient ◽  
Fungal Promoters

ABSTRACT Four expression cassettes containing strong fungal promoters, a signal sequence for protein translocation, a KEX protease cleavage site, and a synthetic gene (tha) encoding the sweet protein thaumatin II were used to overexpress this protein in Aspergillus awamori lpr66, a PepA protease-deficient strain. The best expression results were obtained with the gdhA promoter ofA. awamori or with the gpdA promoter ofAspergillus nidulans. There was good correlation oftha gene dosage, transcript levels, and thaumatin secretion. The thaumatin gene was expressed as a transcript of the expected size in each construction (1.9 or 1.4 kb), and the transcript levels and thaumatin production rate decayed at the end of the growth phase, except in the double transformant TB2b1-44-GD5, in which secretion of thaumatin continued until 96 h. The recombinant thaumatin secreted by a high-production transformant was purified to homogeneity, giving one major component and two minor components. In all cases, cleavage of the fused protein occurred at the KEX recognition sequence. This work provides new expression systems inA. awamori that result in very high levels of thaumatin production.

scholarly journals Colistin and Isavuconazole Interact Synergistically In Vitro against Aspergillus nidulans and Aspergillus niger

2020 ◽  
Vol 8 (9) ◽  
pp. 1447
Author(s):  
Patrick Schwarz ◽  
Elie Djenontin ◽  
Eric Dannaoui
Keyword(s):  
Aspergillus Niger ◽  
Aspergillus Nidulans ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Important Species ◽  
Agar Diffusion ◽  
Agar Diffusion Assay ◽  
Diffusion Assay

The in vitro interactions of isavuconazole in combination with colistin were evaluated against 55 clinical Aspergillus species isolates belonging to the five most important species (Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) responsible for human aspergillosis by a microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference method for antifungal susceptibility testing. Selected isolates (A. nidulans, n = 10; A. niger, n = 15) were additionally evaluated by an agar diffusion assay using isavuconazole gradient concentration strips with or without colistin incorporated Roswell Parc Memorial Institute (RPMI) agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index. Using the checkerboard method, combination isavuconazole–colistin was synergistic for 100% of the 15 A. nidulans isolates and for 60% of the 20 A. niger isolates. No interactions were found for any of the other isolates. By agar diffusion assay, minimal inhibitory concentrations (MICs) in combination decreased compared to isavuconazole alone for 92% of the isolates. No interactions were found for any A. nidulans isolates, but synergy was observed for 40% of the A. niger isolates. A poor essential agreement of EUCAST and gradient concentration strip MICs at ± 2 log2 dilutions with 0% was obtained. Antagonistic interactions were never observed regardless of the technique used.

scholarly journals Quantitative Analysis of the Relative Transcript Levels of ABC Transporter Atr Genes in Aspergillus nidulans by Real-Time Reverse Transcription-PCR Assay

2002 ◽  
Vol 68 (3) ◽  
pp. 1351-1357 ◽  
Author(s):  
Camile Pizeta Semighini ◽  
Mozart Marins ◽  
Maria Helena S. Goldman ◽  
Gustavo Henrique Goldman
Keyword(s):  
Quantitative Analysis ◽  
Real Time ◽  
Aspergillus Nidulans ◽  
Abc Transporter ◽  
Reverse Transcription ◽  
Wild Type ◽  
Rt Pcr ◽  
Transcript Levels ◽  
Reverse Transcription Pcr ◽  
Nitroquinoline Oxide

ABSTRACT The development of assays for quantitative analysis of the relative transcript levels of ABC transporter genes by real-time reverse transcription-PCR (RT-PCR) might provide important information about multidrug resistance in filamentous fungi. Here, we evaluate the potential of real-time RT-PCR to quantify the relative transcript levels of ABC transporter Atr genes from Aspergillus nidulans. The AtrA to AtrD genes showed different and higher levels in the presence of structurally unrelated drugs, such as camptothecin, imazalil, itraconazole, hygromycin, and 4-nitroquinoline oxide. We also verified the relative transcript levels of the Atr genes in the A. nidulans imazalil-resistant mutants. These genes displayed a very complex pattern in different ima genetic backgrounds. The imaB mutant has higher basal transcript levels of AtrB and -D than those of the wild-type strain. The levels of these two genes are comparable when the imaB mutant is grown in the presence and absence of imazalil. The imaC, -D, and -H mutants have higher basal levels of AtrA than that of the wild type. The same behavior is observed for the relative transcript levels of AtrB in the imaG mutant background.

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