United States Department of Agriculture—Agricultural Research Service studies on polyketide toxins of <i>Fusarium oxysporum</i> f sp <i>vasinfectum</i>: potential targets for disease control

Bell, Alois A.; Wheeler, Michael H.; Liu, Jinggao; Stipanovic, Robert D.; Puckhaber, Lorraine S.; Orta, Heather

doi:10.1002/ps.713

Cited by 68 publications

(59 citation statements)

References 49 publications

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“…Purification and Structural Characterization of the aurZspecific Compound YWA1-The ⌬aurZ mutant was grown at room temperature in darkness for 14 days on agar plates containing Bells medium (27) with maltose as the carbon source and urea as the nitrogen source as described in Ref. 4.…”

Section: Methodsmentioning

confidence: 99%

Two Novel Classes of Enzymes Are Required for the Biosynthesis of Aurofusarin in Fusarium graminearum

Frandsen

Schütt

Lund

et al. 2011

Journal of Biological Chemistry

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Previous studies have reported the functional characterization of 9 out of 11 genes found in the gene cluster responsible for biosynthesis of the polyketide pigment aurofusarin in Fusarium graminearum. Here we reanalyze the function of a putative aurofusarin pump (AurT) and the two remaining orphan genes, aurZ and aurS. Targeted gene replacement of aurZ resulted in the discovery that the compound YWA1, rather than nor-rubrofusarin, is the primary product of F. graminearum polyketide synthase 12 (FgPKS12). AurZ is the first representative of a novel class of dehydratases that act on hydroxylated ␥-pyrones. Replacement of the aurS gene resulted in accumulation of rubrofusarin, an intermediate that also accumulates when the GIP1, aurF, or aurO genes in the aurofusarin cluster are deleted. Based on the shared phenotype and predicted subcellular localization, we propose that AurS is a member of an extracellular enzyme complex (GIP1-AurF-AurO-AurS) responsible for converting rubrofusarin into aurofusarin. This implies that rubrofusarin, rather than aurofusarin, is pumped across the plasma membrane. Replacement of the putative aurofusarin pump aurT increased the rubrofusarin-to-aurofusarin ratio, supporting that rubrofusarin is normally pumped across the plasma membrane. These results provide functional information on two novel classes of proteins and their contribution to polyketide pigment biosynthesis.The plant pathogenic fungus Fusarium graminearum (teleomorph Gibberella zeae) is capable of producing a plethora of secondary metabolites, many of which belong to the polyketide class of compounds, such as the mycotoxins zearalenone, fusarin C, and aurofusarin (1). The F. graminearum genome encodes 15 polyketide synthases (PKS) 2 (2, 3), of which FgPKS12 is the progenitor of nor-rubrofusarin/rubrofusarin/aurofusarin (4, 5), FgPKS4 and FgPKS13 are the progenitors of zearalenone (1, 6), FgPKS10 is the progenitor of fusarin C (7, 8), and FgPKS3 is the progenitor of an uncharacterized black/purple perithecial pigment (8). PKS genes are typically found in gene clusters that comprise genes encoding transcription factor, transporters, and tailoring enzymes required for biosynthesis of the final product (1, 4 -6). In addition to genes encoding well characterized classes of enzymes, the clusters typically also include orphan genes that encode proteins annotated as "hypothetical" or "conserved hypothetical proteins," signifying that no similarity to any previously characterized protein has been found. In the case of F. graminearum, more than half of all gene models found in the Fusarium graminearum Genome Database from the Munich Information Center for Protein Sequences (MIPS) fall into either of these two categories (9).Functional characterization of hypothetical proteins is challenging, but those belonging to secondary metabolite gene clusters provide a unique opportunity because their location suggests a function in the respective biosynthetic pathways. The PKS12 gene cluster in F. graminearum, which is responsible for biosyn...

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Section: Methodsmentioning

confidence: 99%

Two Novel Classes of Enzymes Are Required for the Biosynthesis of Aurofusarin in Fusarium graminearum

Frandsen

Schütt

Lund

et al. 2011

Journal of Biological Chemistry

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“…The insoluble sodium salt of the pigment recovered from the interface was suspended in 0.1 N hydrochloric acid, re-extracted with chloroform, and dried (anhydrous sodium sulfate). The extract was concentrated by rotary evaporation; the purple colored compound was re-crystallized with chloroform yielding the pure pigment (Bell et al 2003;Brewer et al 1973). The pigment was TLC purified.…”

Section: Chemicalsmentioning

confidence: 99%

“…Polyketides constitute the largest and diverse group among secondary metabolites. Bikaverin is a polyketide compound, frequently biosynthesized by various Fusarium species (Bell et al 2003). It exhibited a broad spectrum of bioactivity such as an antibiotic effective against Leishmania braziliensis (Balan et al 1970), nematicidal activity against the pine wood nematode Bursaphelenchus xylophilus (Kwon et al 2007), and antioomycete activity in the control of tomato late blight disease (Son et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Neuroprotective Effects of Bikaverin on H2O2-Induced Oxidative Stress Mediated Neuronal Damage in SH-SY5Y Cell Line

et al. 2014

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The generation of free radicals and oxidative stress has been linked to several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, Huntington's disease, and Amyotrophic lateral sclerosis. The use of free radical scavenging molecules for the reduction of intracellular reactive oxygen species is one of the strategies used in the clinical management of neurodegeneration. Fungal secondary metabolism is a rich source of novel molecules with potential bioactivity. In the current study, bikaverin was extracted from Fusarium oxysporum f. sp. lycopersici and its structural characterization was carried out. Further, we explored the protective effects of bikaverin on oxidative stress and its anti-apoptotic mechanism to attenuate H 2 O 2 -induced neurotoxicity using human neuroblastoma SH-SY5Y cells. Our results elucidate that pretreatment of neurons with bikaverin attenuates the mitochondrial and plasma membrane damage induced by 100 lM H 2 O 2 to 82 and 26 % as evidenced by MTT and LDH assays. H 2 O 2 induced depletion of antioxidant enzyme status was also replenished by bikaverin which was confirmed by Realtime Quantitative PCR analysis of SOD and CAT genes. Bikaverin pretreatment efficiently potentiated the H 2 O 2 -induced neuronal markers, such as BDNF, TH, and AADC expression, which orchestrate the neuronal damage of the cell. The H 2 O 2 -induced damage to cells, nuclear, and mitochondrial integrity was also restored by bikaverin. Bikaverin could be developed as a preventive agent against neurodegeneration and as an alternative to some of the toxic synthetic antioxidants.

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“…Many fungi that exhibit these characteristic properties, in general, are capable of reducing Au (III) or Ag (I) [22]. Besides these extracellular enzymes, several naphthoquinones [23][24][25] and anthraquinones [26] with excellent redox properties, were reported in Fusarium oxysporum that could act as electron shuttle in metal reductions [28][29][30]. Specifically the following results towards production of nanoparticles have been achieved using fungi:…”

Section: Mechanism Of Nanoparticle Production Through Fungimentioning

confidence: 99%

Biosynthesis of Silver Nanoparticles by Fungus Trichoderma Reesei (A Route for Large-Scale Production of AgNPs)

Vahabi¹,

Mansoori²,

Karimi³

2011

Insciences J.

366

156

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Abstract:One of the requirements for advancement of nanotechnology are the development of reliable experimental protocols for the synthesis of nanomaterials over a range of biological compositions, sizes and high monodispersity. An attractive possibility of green nanotechnology is to use micro-organisms in the synthesis of nanoparticles. Recently, the utilization of biological systems, especially fungi, has emerged as a novel method for the synthesis of nanoparticles. Nanoparticles are considered as fundamental molecular building blocks for nanotechnology. They are the starting points for preparing many nanostructured materials and devices. In this paper we report the extracellular biosynthesis of silver nanoparticles (AgNPs) by using a fungus named Trichoderma Reesei (also known as Hypocrea jecorina). In the biosynthesis of AgNPs by this fungus, the fungus mycelium is exposed to the silver nitrate solution. That prompts the fungus to produce enzymes and metabolites for its own survival. In this process the toxic Ag+ ions are reduced to the nonetoxic metallic AgNPs through the catalytic effect of the extracellular enzyme and metabolites of the fungus. Absorption UV-Visible light spectroscopy is used to follow up with the reaction process. Fluorescence emission spectroscopy is used to produce detailed information on the progress of reduction of silver nitrate (formation of silver nanoparticles) on the nanosecond timescale. Fourier transform infrared spectroscopy is used for quantitative analyses of the reaction products. Our measurements indicate that extracellular biosynthesis of AgNPs by Trichoderma reesei produces AgNPs with the diameters in the range of 5-50 nm. Trichoderma Reesei is an environmentally friendly fungus, and it is well known for its formation of extracellular enzyme and metabolites in very large amounts, much higher than other fungi. The present process is an excellent candidate for industrial scale production of silver nanoparticles. 66Insciences Journal | Nanotechnology

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United States Department of Agriculture—Agricultural Research Service studies on polyketide toxins of Fusarium oxysporum f sp vasinfectum: potential targets for disease control

Cited by 68 publications

References 49 publications

Two Novel Classes of Enzymes Are Required for the Biosynthesis of Aurofusarin in Fusarium graminearum

Two Novel Classes of Enzymes Are Required for the Biosynthesis of Aurofusarin in Fusarium graminearum

Neuroprotective Effects of Bikaverin on H2O2-Induced Oxidative Stress Mediated Neuronal Damage in SH-SY5Y Cell Line

Biosynthesis of Silver Nanoparticles by Fungus Trichoderma Reesei (A Route for Large-Scale Production of AgNPs)

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