Functional characterization of a C-4 sterol methyl oxidase from the endomycorrhizal fungus Glomus intraradices.
Sterols are crucial components of eukaryotic membranes that control membrane fluidity and permeability. They play an important role in cell signaling, polarity and sorting. Since many steps in the pathway are essential, sterol biosynthesis inhibitors (SBI) are widely used as antifungal agents. This work reports the identification and the characterization of a C-4 sterol methyl oxidase (SMO), the first gene involved in the sterol biosynthetic pathway, so far described from an arbuscular mycorrhizal fungus. The sequence, called GintSMO, shows a primary structure, a hydrophobicity profile and a pattern of histidine-rich motifs which are typical of C-4 methyl sterol oxidases. The complementation assay in a Saccharomyces cerevisiae mutant strain demonstrates that GintSMO encodes a functional SMO. Changes in GintSMO transcript levels and in the amount of the sterol precursor squalene were observed in in vitro grown extraradical structures exposed to the fenpropimorph SBI fungicide.
Oger
Elodie
E
Dipartimento di Biologia Vegetale, Università degli Studi di Torino, Torino, Italy.
Ghignone
Stefano
S
Campagnac
Estelle
E
Fontaine
Joël
J
Grandmougin-Ferjani
Anne
A
Lanfranco
Luisa
L
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D055137:Glomeromycota / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D038821:Mycorrhizae / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D016415:Sequence Alignment; D013261:Sterols / Q000378:metabolism
D005656:Fungal Proteins; D013261:Sterols; D006899:Mixed Function Oxygenases; C027532:methylsterol monooxygenase