title: Characterization of IDI-4, a bZIP transcription factor inducing autophagy and cell death in the fungus Podospora anserina.
abstract: In filamentous fungi a cell death reaction occurs when hyphae of unlike genotype fuse. This phenomenon is referred to as heterokaryon incompatibility. In Podospora anserina, this cell death reaction was found to be associated with the transcriptional induction of a set of genes termed idi genes (for induced during incompatibility) and activation of autophagy. Herein, we describe the characterization of idi-4, a novel idi gene encoding a bZIP transcription factor. Expression of idi-4 is induced during cell death by incompatibility and in various stress conditions. Inactivation of idi-4 by gene replacement does not suppress incompatibility but we show that overexpression of idi-4 triggers cell death. Strains which undergo idi-4-induced cell death display cytological hallmarks of cell death by incompatibility notably induction of autophagy. We also report that increased expression of idi-4 leads to transcriptional induction of other idi genes such as idi-7, the orthologue of the yeast ATG8 autophagy gene. Together these results establish IDI-4 as one of the transcription factor regulating autophagy and cell fate in Podospora.
authors.affiliation: Laboratoire de Génétique Moléculaire des Champignons, Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS/Université de Bordeaux 2, 1 rue Camille St Saëns, 33077 Bordeaux cedex, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Dementhon
authors.forename: Sven J
authors.initials: SJ
authors.lastname: Saupe
authors.forename: Corinne
authors.initials: C
authors.lastname: Clavé
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001343:Autophagy / Q000502:physiology*; D000071190:Autophagy-Related Protein 8 Family; D001483:Base Sequence; D016923:Cell Death / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D048430:Cell Shape; D018387:Codon, Initiator; D015966:Gene Expression Regulation, Fungal; D006358:Hot Temperature; D008869:Microtubule-Associated Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D048468:Podospora / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C113757:ATG8 protein, S cerevisiae; D000071190:Autophagy-Related Protein 8 Family; D018387:Codon, Initiator; D008869:Microtubule-Associated Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors