scholarly journals Internalization of the Aspergillus nidulans AstA Transporter into Mitochondria Depends on Growth Conditions, and Affects ATP Levels and Sulfite Oxidase Activity

2020 ◽  
Vol 21 (20) ◽  
pp. 7727
Author(s):  
Sebastian Piłsyk ◽  
Adam Mieczkowski ◽  
Maciej P. Golan ◽  
Agata Wawrzyniak ◽  
Joanna S. Kruszewska
Keyword(s):  
Aspergillus Nidulans ◽  
Oxidase Activity ◽  
Energy State ◽  
Sulfur Metabolism ◽  
Growth Conditions ◽  
Sulfite Oxidase ◽  
Gene Encoding ◽  
Atp Levels ◽  
Asta Gene ◽  
Overexpressing Strain

The astA gene encoding an alternative sulfate transporter was originally cloned from the genome of the Japanese Aspergillus nidulans isolate as a suppressor of sulfate permease-deficient strains. Expression of the astA gene is under the control of the sulfur metabolite repression system. The encoded protein transports sulfate across the cell membrane. In this study we show that AstA, having orthologs in numerous pathogenic or endophytic fungi, has a second function and, depending on growth conditions, can be translocated into mitochondria. This effect is especially pronounced when an astA-overexpressing strain grows on solid medium at 37 °C. AstA is also recruited to the mitochondria in the presence of mitochondria-affecting compounds such as menadione or antimycin A, which are also detrimental to the growth of the astA-overexpressing strain. Disruption of the Hsp70–Porin1 mitochondrial import system either by methylene blue, an Hsp70 inhibitor, or by deletion of the porin1-encoding gene abolishes AstA translocation into the mitochondria. Furthermore, we observed altered ATP levels and sulfite oxidase activity in the astA-overexpressing strain in a manner dependent on sulfur sources. The presented data indicate that AstA is also involved in the mitochondrial sulfur metabolism in some fungi, and thereby indirectly manages redox potential and energy state.

scholarly journals Isolation of a gene required for programmed initiation of development by Aspergillus nidulans.

1992 ◽  
Vol 12 (9) ◽  
pp. 3827-3833 ◽  
Author(s):  
T H Adams ◽  
W A Hide ◽  
L N Yager ◽  
B N Lee
Keyword(s):  
Life Cycle ◽  
Aspergillus Nidulans ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Nutrient Deprivation ◽  
Deletion Mutants ◽  
Wild Type ◽  
Microbial Development ◽  
Type Strains ◽  
Posttranscriptional Level

In contrast to many other cases in microbial development, Aspergillus nidulans conidiophore production initiates primarily as a programmed part of the life cycle rather than as a response to nutrient deprivation. Mutations in the acoD locus result in "fluffy" colonies that appear to grow faster than the wild type and proliferate as undifferentiated masses of vegetative cells. We show that unlike wild-type strains, acoD deletion mutants are unable to make conidiophores under optimal growth conditions but can be induced to conidiate when growth is nutritionally limited. The requirement for acoD in conidiophore development occurs prior to activation of brlA, a primary regulator of development. The acoD transcript is present both in vegetative hyphae prior to developmental induction and in developing cultures. However, the effects of acoD mutations are detectable only after developmental induction. We propose that acoD activity is primarily controlled at the posttranscriptional level and that it is required to direct developmentally specific changes that bring about growth inhibition and activation of brlA expression to result in conidiophore development.

scholarly journals Control of reactive oxygen species (ROS) production through histidine kinases in Aspergillus nidulans under different growth conditions

FEBS Open Bio ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 90-95 ◽  
Author(s):  
Saki Hayashi ◽  
Megumi Yoshioka ◽  
Tetsuji Matsui ◽  
Kensuke Kojima ◽  
Masashi Kato ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Aspergillus Nidulans ◽  
Reactive Oxygen ◽  
Growth Conditions ◽  
Ros Production ◽  
Oxygen Species ◽  
Histidine Kinases

scholarly journals Level of Sulfite Oxidase Activity Affects Sulfur and Carbon Metabolism in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Dinara Oshanova ◽  
Assylay Kurmanbayeva ◽  
Aizat Bekturova ◽  
Aigerim Soltabayeva ◽  
Zhadyrassyn Nurbekova ◽  
...  
Keyword(s):  
Sulfur Metabolism ◽  
Biomass Accumulation ◽  
Sulfite Oxidase ◽  
Sulfite Reductase ◽  
Wild Type ◽  
Direct Exposure ◽  
Important Player ◽  
Sulfur Supply ◽  
Lower Biomass

Molybdenum cofactor containing sulfite oxidase (SO) enzyme is an important player in protecting plants against exogenous toxic sulfite. It was also demonstrated that SO activity is essential to cope with rising dark-induced endogenous sulfite levels and maintain optimal carbon and sulfur metabolism in tomato plants exposed to extended dark stress. The response of SO and sulfite reductase to direct exposure of low and high levels of sulfate and carbon was rarely shown. By employing Arabidopsis wild-type, sulfite reductase, and SO-modulated plants supplied with excess or limited carbon or sulfur supply, the current study demonstrates the important role of SO in carbon and sulfur metabolism. Application of low and excess sucrose, or sulfate levels, led to lower biomass accumulation rates, followed by enhanced sulfite accumulation in SO impaired mutant compared with wild-type. SO-impairment resulted in the channeling of sulfite to the sulfate reduction pathway, resulting in an overflow of organic S accumulation. In addition, sulfite enhancement was followed by oxidative stress contributing as well to the lower biomass accumulation in SO-modulated plants. These results indicate that the role of SO is not limited to protection against elevated sulfite toxicity but to maintaining optimal carbon and sulfur metabolism in Arabidopsis plants.

scholarly journals Formate-Dependent H2 Production by the Mesophilic Methanogen Methanococcus maripaludis

2008 ◽  
Vol 74 (21) ◽  
pp. 6584-6590 ◽  
Author(s):  
Boguslaw Lupa ◽  
Erik L. Hendrickson ◽  
John A. Leigh ◽  
William B. Whitman
Keyword(s):  
Dry Weight ◽  
Maximal Activity ◽  
Growth Conditions ◽  
H2 Production ◽  
Resting Cells ◽  
Wild Type ◽  
Methanococcus Maripaludis ◽  
Gene Encoding ◽  
Major Pathway ◽  
Key Enzyme

ABSTRACT Methanococcus maripaludis, an H2- and formate-utilizing methanogen, produced H2 at high rates from formate. The rates and kinetics of H2 production depended upon the growth conditions, and H2 availability during growth was a major factor. Specific activities of resting cells grown with formate or H2 were 0.4 to 1.4 U�mg−1 (dry weight). H2 production in formate-grown cells followed Michaelis-Menten kinetics, and the concentration of formate required for half-maximal activity (Kf ) was 3.6 mM. In contrast, in H2-grown cells this process followed sigmoidal kinetics, and the Kf was 9 mM. A key enzyme for formate-dependent H2 production was formate dehydrogenase, Fdh. H2 production and growth were severely reduced in a mutant containing a deletion of the gene encoding the Fdh1 isozyme, indicating that it was the primary Fdh. In contrast, a mutant containing a deletion of the gene encoding the Fdh2 isozyme possessed near-wild-type activities, indicating that this isozyme did not play a major role. H2 production by a mutant containing a deletion of the coenzyme F420-reducing hydrogenase Fru was also severely reduced, suggesting that the major pathway of H2 production comprised Fdh1 and Fru. Because a Δfru-Δfrc mutant retained 10% of the wild-type activity, an additional pathway is present. Mutants possessing deletions of the gene encoding the F420-dependent methylene-H4MTP dehydrogenase (Mtd) or the H2-forming methylene-H4MTP dehydrogenase (Hmd) also possessed reduced activity, which suggested that this second pathway was comprised of Fdh1-Mtd-Hmd. In contrast to H2 production, the cellular rates of methanogenesis were unaffected in these mutants, which suggested that the observed H2 production was not a direct intermediate of methanogenesis. In conclusion, high rates of formate-dependent H2 production demonstrated the potential of M. maripaludis for the microbial production of H2 from formate.

scholarly journals Regulation of freA, acoA, lysF, and cycA Expression by Iron Availability in Aspergillus nidulans

2002 ◽  
Vol 68 (11) ◽  
pp. 5769-5772 ◽  
Author(s):  
Harald Oberegger ◽  
Michelle Schoeser ◽  
Ivo Zadra ◽  
Markus Schrettl ◽  
Walther Parson ◽  
...  
Keyword(s):  
Aspergillus Nidulans ◽  
Iron Homeostasis ◽  
Regulatory Mechanism ◽  
Growth Conditions ◽  
Iron Limitation ◽  
Transcriptional Level ◽  
Iron Availability ◽  
Gata Factor ◽  
Genes Encoding ◽  
Encoding Gene

ABSTRACT In the filamentous fungus Aspergillus nidulans, iron homeostasis is regulated at the transcriptional level by the negative-acting GATA factor SREA. In this study the expression of a putative heme-containing metalloreductase-encoding gene, freA, was found to be upregulated by iron limitation independently of SREA, demonstrating the existence of an iron-regulatory mechanism which does not involve SREA. In contrast to freA, various other genes encoding proteins in need of iron-containing cofactors—acoA, lysF, and cycA—were downregulated in response to iron depletion. Remarkably, SREA deficiency led to increased expression of acoA, lysF, and cycA under iron-replete growth conditions.

Identification of a bacterial di-haem cytochrome c peroxidase from Methylomicrobium album BG8

Microbiology ◽  
2010 ◽  
Vol 156 (9) ◽  
pp. 2682-2690 ◽  
Author(s):  
O. A. Karlsen ◽  
Ø. Larsen ◽  
H. B. Jensen
Keyword(s):  
Copper Ions ◽  
Sequence Similarity ◽  
Physiological Role ◽  
Growth Conditions ◽  
Inverse Pcr ◽  
Restriction Enzyme Digestion ◽  
Methylococcus Capsulatus ◽  
Gene Encoding ◽  
Reading Frame ◽  
Methylomicrobium Album

The nucleotide sequence of an open reading frame (corB) downstream of the copper-repressible CorA-encoding gene of the methanotrophic bacterium Methylomicrobium album BG8 was obtained by restriction enzyme digestion and inverse PCR. The amino acid sequence deduced from this gene showed significant sequence similarity to the surface-associated di-haem cytochrome c peroxidase (SACCP) previously isolated from Methylococcus capsulatus (Bath), including both c-type haem-binding motifs. Homology analysis placed this protein, phylogenetically, within the subfamily containing the M. capsulatus SACCP of the bacterial di-haem cytochrome c peroxidase (BCCP) family of proteins. Immunospecific recognition confirmed synthesis of the M. album CorB as a protein non-covalently associated with the outer membrane and exposed to the periplasm. corB expression is regulated by the availability of copper ions during growth and the protein is most abundant in M. album when grown at a low copper-to-biomass ratio, indicating an important physiological role of CorB under these growth conditions. corB was co-transcribed with the gene encoding CorA, constituting a copper-responding operon, which appears to be under the control of a σ 54-dependent promoter. M. album CorB is the second isolated member of the recently described subfamily of the BCCP family of proteins. So far, these proteins have only been described in methanotrophic bacteria.

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