title: Identification of NoxD/Pro41 as the homologue of the p22phox NADPH oxidase subunit in fungi.
abstract: NADPH oxidases (Nox) are membrane complexes that produce O2(-). Researches in mammals, plants and fungi highlight the involvement of Nox-generated ROS in cell proliferation, differentiation and defense. In mammals, the core enzyme gp91(phox)/Nox2 is associated with p22(phox) forming the flavocytochrome b558 ready for activation by a cytosolic complex. Intriguingly, no homologue of the p22(phox) gene has been found in fungal genomes, questioning how the flavoenzyme forms. Using whole genome sequencing combined with phylogenetic analysis and structural studies, we identify the fungal p22(phox) homologue as being mutated in the Podospora anserina mutant IDC(509). Functional studies show that the fungal p22(phox), PaNoxD, acts along PaNox1, but not PaNox2, a second fungal gp91(phox) homologue. Finally, cytological analysis of functional tagged versions of PaNox1, PaNoxD and PaNoxR shows clear co-localization of PaNoxD and PaNox1 and unravel a dynamic assembly of the complex in the endoplasmic reticulum and in the vacuolar system.
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain, case courrier 7040 Lamarck, 75205, Paris Cedex 13, France; Univ Paris Sud, Institut de Génétique et Microbiologie, UMR8621, 91405, Orsay Cedex, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Lacaze
authors.forename: Hervé
authors.initials: H
authors.lastname: Lalucque
authors.forename: Ulrike
authors.initials: U
authors.lastname: Siegmund
authors.forename: Philippe
authors.initials: P
authors.lastname: Silar
authors.forename: Sylvain
authors.initials: S
authors.lastname: Brun
mesh_terms: D000595:Amino Acid Sequence; D003573:Cytochrome b Group / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D016681:Genome, Fungal; D009154:Mutation; D025282:Mycelium / Q000648:ultrastructure; D019255:NADPH Oxidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D048468:Podospora / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA; D013481:Superoxides / Q000378:metabolism; D014617:Vacuoles / Q000201:enzymology*
chemical_list: D003573:Cytochrome b Group; D013481:Superoxides; C036888:cytochrome b558; D019255:NADPH Oxidases; C086986:CYBA protein, human