The Nox/Ferric reductase/Ferric reductase-like families of Eumycetes

Grissa, Ibtissem; Bidard, Frédérique; Grognet, Pierre; Grossetête, Sandrine; Silar, Philippe

doi:10.1016/j.funbio.2010.07.002

Cited by 28 publications

(18 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Position-specific iterated (PSI)-BLAST analyses with the sequence of the catalytic subunit of the human NOX2 against the yeast genome showed that all features of NOX enzymes could be found in yeast ferric reductases, which are, like NADPH oxidases, proven flavocytochromes b 558 (16). We conclude that within the large NOX protein superfamily functional diversity developed and a new function (ferric reductase or, more generally, IMR) arose (11). Among the yeast FRE subfamily the closest homolog to human NOX enzymes was found to be the yeast ORF YGL160W, bearing 32.1% sequence similarity (16.6% identity) to NOX5.…”

Section: Resultsmentioning

confidence: 84%

Yno1p/Aim14p, a NADPH-oxidase ortholog, controls extramitochondrial reactive oxygen species generation, apoptosis, and actin cable formation in yeast

Rinnerthaler

Büttner

Laun

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

131

136

View full text Add to dashboard Cite

The large protein superfamily of NADPH oxidases (NOX enzymes) is found in members of all eukaryotic kingdoms: animals, plants, fungi, and protists. The physiological functions of these NOX enzymes range from defense to specialized oxidative biosynthesis and to signaling. In filamentous fungi, NOX enzymes are involved in signaling cell differentiation, in particular in the formation of fruiting bodies. On the basis of bioinformatics analysis, until now it was believed that the genomes of unicellular fungi like Saccharomyces cerevisiae and Schizosaccharomyces pombe do not harbor genes coding for NOX enzymes. Nevertheless, the genome of S. cerevisiae contains nine ORFs showing sequence similarity to the catalytic subunits of mammalian NOX enzymes, only some of which have been functionally assigned as ferric reductases involved in iron ion transport. Here we show that one of the nine ORFs (YGL160W, AIM14) encodes a genuine NADPH oxidase, which is located in the endoplasmic reticulum (ER) and produces superoxide in a NADPH-dependent fashion. We renamed this ORF YNO1 (yeast NADPH oxidase 1). Overexpression of YNO1 causes YCA1-dependent apoptosis, whereas deletion of the gene makes cells less sensitive to apoptotic stimuli. Several independent lines of evidence point to regulation of the actin cytoskeleton by reactive oxygen species (ROS) produced by Yno1p.cell cycle | integral membrane reductase | wiskostatin | latrunculin R eactive oxygen species (ROS) have multiple roles in physiology and pathophysiology, in particular during aging and induction of programmed cell death. This includes also nonmitochondrial sources, besides the long-studied mitochondrially generated ROS. These findings can be viewed as important additions to the classical "free radical theory of aging" (1) and theories developed thereafter (2, 3).In higher organisms, among others, at least two major sources of superoxide other than mitochondria are known. On the one hand, xanthine oxidase, an enzyme in the catabolism of purines, which catalyses the oxidation of hypoxanthine to xanthine and to uric acid, produces superoxide (4). On the other hand, NADPH oxidases (NOX) catalyze the production of superoxide from oxygen and NADPH (5).The NADPH oxidase superfamily of membrane-located enzymes of higher cells has been known for a decade (for review, ref. 5). Whereas the human NOX2 was discovered early on, other NOX (Nox1/3/4/5) as well as dual oxidase (DUOX) (Duox1/2) enzymes (displaying two domains: a NADPH oxidase domain and a peroxidase domain) have been found relatively recently in human cells. The human NOX2 was discovered as a defense enzyme of neutrophils and macrophages, which produce a burst of superoxide (O 2 · − ) as a first line of defense against invading microorganisms. Although X-ray or NMR structure determinations are not available, we know from indirect evidence and bioinformatics that the catalytic subunit of the macrophage enzyme contains six transmembrane helices, is located in the plasma membrane, and produces superoxide in a vectorial ...

show abstract

Section: Resultsmentioning

confidence: 84%

Yno1p/Aim14p, a NADPH-oxidase ortholog, controls extramitochondrial reactive oxygen species generation, apoptosis, and actin cable formation in yeast

Rinnerthaler

Büttner

Laun

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

131

136

View full text Add to dashboard Cite

show abstract

“…However, the molecular genetics of the enzymatic reduction of ferric to ferrous iron have not been investigated for this pathogen. Ferric reductases are present in all fungal species, with variable numbers predicted across fungal genomes; these enzymes have been studied extensively in S. cerevisiae and, to some extent, in C. albicans, S. pombe, and A. fumigatus (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)42). In our study, we identified eight candidate ferric reductase (FRE) genes in C. neoformans, characterized their expression and contributions to reductase activity, and investigated their roles in virulence factor production.…”

Section: Discussionmentioning

confidence: 99%

Role of Ferric Reductases in Iron Acquisition and Virulence in the Fungal Pathogen Cryptococcus neoformans

Saikia

Oliveira

et al. 2014

Infect Immun

View full text Add to dashboard Cite

Iron acquisition is critical for the ability of the pathogenic yeast Cryptococcus neoformans to cause disease in vertebrate hosts. In particular, iron overload exacerbates cryptococcal disease in an animal model, defects in iron acquisition attenuate virulence, and iron availability influences the expression of major virulence factors. C. neoformans acquires iron by multiple mechanisms, including a ferroxidase-permease high-affinity system, siderophore uptake, and utilization of both heme and transferrin. In this study, we examined the expression of eight candidate ferric reductase genes and their contributions to iron acquisition as well as to ferric and cupric reductase activities. We found that loss of the FRE4 gene resulted in a defect in production of the virulence factor melanin and increased susceptibility to azole antifungal drugs. In addition, the FRE2 gene was important for growth on the iron sources heme and transferrin, which are relevant for proliferation in the host. Fre2 may participate with the ferroxidase Cfo1 of the high-affinity uptake system for growth on heme, because a mutant lacking both genes showed a more pronounced growth defect than the fre2 single mutant. A role for Fre2 in iron acquisition is consistent with the attenuation of virulence observed for the fre2 mutant. This mutant also was defective in accumulation in the brains of infected mice, a phenotype previously observed for mutants with defects in high-affinity iron uptake (e.g., the cfo1 mutant). Overall, this study provides a more detailed view of the iron acquisition components required for C. neoformans to cause cryptococcosis.

show abstract

“…Fungi such as Pycnoporus cinnabarinus use laccases, while others like the white rot Phanerochaete chrysosporium use several classical ROS-generating oxidative enzymes [14], [15]. Nevertheless, in every case H 2 O 2 may be produced to degrade cellulose [16], [17].…”

Section: Introductionmentioning

confidence: 99%

Wood Utilization Is Dependent on Catalase Activities in the Filamentous Fungus Podospora anserina

et al. 2012

Self Cite

View full text Add to dashboard Cite

Catalases are enzymes that play critical roles in protecting cells against the toxic effects of hydrogen peroxide. They are implicated in various physiological and pathological conditions but some of their functions remain unclear. In order to decipher the role(s) of catalases during the life cycle of Podospora anserina, we analyzed the role of the four monofunctional catalases and one bifunctional catalase-peroxidase genes present in its genome. The five genes were deleted and the phenotypes of each single and all multiple mutants were investigated. Intriguingly, although the genes are differently expressed during the life cycle, catalase activity is dispensable during both vegetative growth and sexual reproduction in laboratory conditions. Catalases are also not essential for cellulose or fatty acid assimilation. In contrast, they are strictly required for efficient utilization of more complex biomass like wood shavings by allowing growth in the presence of lignin. The secreted CATB and cytosolic CAT2 are the major catalases implicated in peroxide resistance, while CAT2 is the major player during complex biomass assimilation. Our results suggest that P. anserina produces external H2O2 to assimilate complex biomass and that catalases are necessary to protect the cells during this process. In addition, the phenotypes of strains lacking only one catalase gene suggest that a decrease of catalase activity improves the capacity of the fungus to degrade complex biomass.

show abstract

The Nox/Ferric reductase/Ferric reductase-like families of Eumycetes

Cited by 28 publications

References 52 publications

Yno1p/Aim14p, a NADPH-oxidase ortholog, controls extramitochondrial reactive oxygen species generation, apoptosis, and actin cable formation in yeast

Yno1p/Aim14p, a NADPH-oxidase ortholog, controls extramitochondrial reactive oxygen species generation, apoptosis, and actin cable formation in yeast

Role of Ferric Reductases in Iron Acquisition and Virulence in the Fungal Pathogen Cryptococcus neoformans

Wood Utilization Is Dependent on Catalase Activities in the Filamentous Fungus Podospora anserina

Contact Info

Product

Resources

About