Identification and Functional Characterization of the 2-Hydroxy Fatty N-Acyl-Δ3(E)-desaturase from Fusarium graminearum

Abstract

⌬3(E)-Unsaturated fatty acids are characteristic components of glycosylceramides from some fungi, including also humanand plant-pathogenic species. The function and genetic basis for this unsaturation is unknown. For Fusarium graminearum, which is pathogenic to grasses and cereals, we could show that the level of ⌬3-unsaturation of glucosylceramide (GlcCer) was highest at low temperatures and decreased when the fungus was grown above 28°C. With a bioinformatics approach, we identified a new family of polypeptides carrying the histidine box motifs characteristic for membrane-bound desaturases. One of the corresponding genes was functionally characterized as a sphingolipid-⌬3(E)-desaturase.

Structural Analysis of Fungal Cerebrosides

“…LCB was first described in monohexosylceramides from Aspergillus oryzae (Fujino and Ohnishi, 1976) and was subsequently isolated from Schizophyllum commune (Kawai and Ikeda, 1985), from the plant pathogen Fusicoccum amygdale (Ballio et al, 1979), and the edible fungi Clitocybe geotropa and Clitocybe nebularis (Fogedal et al, 1986). CMHs were further characterized in lipid extracts from the fungal species Alternaria raphani (Wang et al, 2009), Aspergillus fumigatus (Boas et al, 1994; Toledo et al, 1999), Aspergillus nidulans (Levery et al, 2002), Aspergillus niger (Levery et al, 2000; Levery, 2005), Aspergillus versicolor (Boas et al, 1994), Acremonium chrysogenum (Sakaki et al, 2001), Amanita muscaria (Weiss and Stiller, 1972), Candida albicans (Matsubara et al, 1987), Candida deformans (Mineki et al, 1994), Candida utilis (Wagner and Zofcsik, 1966), Colletotrichum gloeosporioides (da Silva et al, 2004), Cryptococcus neoformans (Rodrigues et al, 2000), Fonsecaea pedrosoi (Nimrichter et al, 2004), Fusarium graminearum (Zaüner et al, 2008), Fusarium solani (Duarte et al, 1998), Ganoderma lucidum (Mizushina et al, 1998), Hansenula anomala (Ng and Laneelle, 1977), Histoplasma capsulatum (Toledo et al, 2001), Hypsizygus marmoreus (Sawabe et al, 1994), Kluyveromyces waltii (Takakuwa et al, 2002), Kluyveromyces thermotolerans (Takakuwa et al, 2002), Kluyveromyces lactis (Takakuwa et al, 2002), Lentinus edodes (Kawai, 1989), Magnaporthe grisea (Koga et al, 1998; Umemura et al, 2000; Maciel et al, 2002), Mortierella alpina (Batrakov et al, 2002), Metrilium senile (Karlsson et al, 1979), Neurospora crassa (Lester et al, 1974; Park et al, 2005), Paracoccidioides brasilensis (Takahashi et al, 1996), Penicillium chrysogenum (Peng et al, 2011), Pichia pastoris (Sakaki et al, 2001), Polyporus ellisii (Gao et al, 2001), Polyporus squamosus (Arigi et al, 2007), Pseudallescheria boydii (Pinto et al, 2002), Rhynchosporium secalis (Sakaki et al, 2001), Saccharomyces kluyveri (Takakuwa et al, 2002), Sordaria macrospore (Sakaki et al, 2001), Sporothrix schenckii (Toledo et al, 2000), Termitomyces albuminosus (Qi et al, 2001), Zygosaccharomyces cidri , and Zygosaccharomyces fermentati (Takakuwa et al, 2002). …”

Highlights of recent progress in plant lipid research

“…Although LCB-phosphates appear to have bioactive properties in plants, the lack of any apparent phenotypes in the LCB Δ4 desaturase mutants was taken as evidence that ∆4-unsaturated sphingolipids, and in particular sphingosine-1-phosphate, do not have the important signaling roles described in mammalian cells or as previously reported in Arabidopsis (L. Michaelson, O45) [30]. Additional studies on the functions of key enzymes involved in sphingolipid metabolism from other plants (e.g., rice ceramidase, M. Pata, P104 [31]) and fungi ( e.g., sphingolipid Δ3-desaturase, S. Z äuner, O46 [32]; cerebroside synthesis, S. Senik, P108) will contribute to generalizations regarding sphingolipid functions.…”

Cerebrosides and Steroids from the Edible Mushroom Meripilus giganteus with Antioxidant Potential

“…Cerebrosides originating from fungi are conserved structures which consist of a ceramide portion with 9-methyl-4,8-sphingadienine in amidic linkage to 2-hydroxyoctadecanoic or 2-hydroxyhexadecanoic acids, and a carbohydrate moiety, namely glucose or galactose. Several fungal cerebrosides were isolated from the plant pathogens Fusarium graminearum [21], Fusarium solani [22], but also from edible and/or medicinal mushrooms for, e.g., Clitocybe geotropa and Clitocybe nebularis [23], Lentinus edodes [24], Polyporus squamosus [25], and Schizophyllum commune [26].…”