Copper-Modulated Gene Expression and Senescence in the Filamentous Fungus <i>Podospora anserina</i>

Borghouts, Corina; Werner, Alexandra; Elthon, Thomas E.; Osiewacz, Heinz D.

doi:10.1128/mcb.21.2.390-399.2001

Cited by 109 publications

(123 citation statements)

References 63 publications

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“…Joseph-Horne et al, 2001). In addition, the activity of COX is copper-dependent and cellular copper homeostasis is a major cause of fungal senescence (Borghouts et al, 2000(Borghouts et al, , 2001. Consistent with this, a low-affinity copper transporter, CN808791, is downregulated in both sectors in all the growth media, and a high-affinity copper transporter (AJ273995) is also downregulated during growth in SDB (Supplementary Table S1).…”

Section: Discussionsupporting

confidence: 61%

Colony sectorization of Metarhizium anisopliae is a sign of ageing

2005

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Spontaneous phenotypic degeneration resulting in sterile sectors is frequently observed when culturing filamentous fungi on artificial medium. Sterile sectors from two different strains of the insect pathogenic fungus Metarhizium anisopliae were investigated and found to contain reduced levels of cAMP and destruxins (insecticidal peptides). Microarray analysis using slides printed with 1730 clones showed that compared to wild-type, sterile sectors down-regulated 759 genes and upregulated 27 genes during growth in Sabouraud glucose broth or on insect cuticle. The differentially expressed genes are largely involved in cell metabolism (18?8 %), cell structure and function (13?6 %) and protein metabolism (8?8 %). Strong oxidative stress was demonstrated in sectorial cultures using the nitro blue tetrazolium assay and these cultures show other syndromes associated with ageing, including mitochondrial DNA alterations. However, genes involved in deoxidation and self-protection (e.g. heat-shock proteins, HSPs) were also upregulated. Further evidence of physiological adaptation by the degenerative sectorial cultures included cell-structure reorganization and the employment of additional signalling pathways. In spite of their very similar appearance, microarray analysis identified 181 genes differentially expressed between the two sectors, and the addition of exogenous cAMP only restored conidiation in one of them. Most of the differentially expressed genes were involved in catabolic or anabolic pathways, but the latter included genes for sporulation. Compared to the mammalian ageing process, sectorization in M. anisopliae showed many similarities, including similar patterns of cAMP production, oxidative stress responses and the involvement of HSPs. Thus, a common molecular machinery for ageing may exist throughout the eukaryotes. INTRODUCTIONThe ascomycete Metarhizium anisopliae is a widespread, soil-borne pathogen of insects, ticks and mites (Roberts & St Leger, 2004). Strains of this fungus are being developed for the control of pest species (Butt et al., 2001). Like many other fungi (Morrow et al., 1989;Kale & Bennett, 1992;Li et al., 1994), it frequently shows culture degeneration (sterile sectorization): a loss or reduction in sporulation and virulence with a fluffy-mycelium type growth. Fungal culture degeneration is usually irreversible and inheritable, and can result in great commercial losses (Li et al., 1994;Horgen et al., 1996;Ryan et al., 2003).Apart from the reports of secondary metabolite decline in degenerative fungal cultures (Wing et al., 1995; Guzman-dePena & Ruiz-Herrera, 1997;Ryan et al., 2002; Kale et al., 2003), little information is available to explain fungal culture instability at the molecular level. However, genomic DNA methylation was reported in a sector of Fusarium oxysporum after successive subculturing (Kim, 1997). In another case, fungal morphological instability was linked to dsRNA virus infection (Dawe & Nuss, 2001).In this study, the spontaneous sterile sectors from two genetically di...

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Section: Discussionsupporting

confidence: 61%

Colony sectorization of Metarhizium anisopliae is a sign of ageing

2005

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“…Importantly, experimental data suggest an age-related increase of copper levels in the cytoplasm of P. anserina (Averbeck et al, 2001;Borghouts et al, 2001). Thus, it is reasonable to speculate about a role of PaMTH1 in counteracting the age-related increase of ROS formation via the metal depending activation of phenolic compounds.…”

Section: Discussionmentioning

confidence: 99%

Over‐expression of an S‐adenosylmethionine‐dependent methyltransferase leads to an extended lifespan of Podospora anserina without impairments in vital functions

Kunstmann

Osiewacz

2008

Aging Cell

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SummaryPaMTH1, a putative methyltransferase previously described to increase in abundance in total protein extracts during aging of Podospora anserina is demonstrated to accumulate in the mitochondrial cell fraction of senescent cultures. The protein is localized in the mitochondrial matrix and displays a methyltransferase activity utilizing flavonoids as substrates. Constitutive over-expression of PaMth1 in P. anserina results in a reduced carbonylation of proteins and an extended lifespan without impairing vital functions suggesting a protecting role of PaMTH1 against oxidative stress.

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“…The regulation of AOX2 is different from the regulation of alternative oxidase genes from other fungi, where the transcription of alternative oxidases increases under low-copper conditions because a shortage of copper impairs the activity of copper-containing respiratory enzymes such as cytochrome c oxidase (Borghouts et al, 2001;Downie & Garland, 1973).…”

Section: Discussionmentioning

confidence: 99%