title: The WW domain protein PRO40 is required for fungal fertility and associates with Woronin bodies.
abstract: Fruiting body formation in ascomycetes is a highly complex process that is under polygenic control and is a fundamental part of the fungal sexual life cycle. However, the molecular determinants regulating this cellular process are largely unknown. Here we show that the sterile pro40 mutant is defective in a 120-kDa WW domain protein that plays a pivotal role in fruiting body maturation of the homothallic ascomycete Sordaria macrospora. Although WW domains occur in many eukaryotic proteins, homologs of PRO40 are present only in filamentous ascomycetes. Complementation analysis with different pro40 mutant strains, using full-sized or truncated versions of the wild-type pro40 gene, revealed that the C terminus of PRO40 is crucial for restoring the fertile phenotype. Using differential centrifugation and protease protection assays, we determined that a PRO40-FLAG fusion protein is located within organelles. Further microscopic investigations of fusion proteins with DsRed or green fluorescent protein polypeptides showed a colocalization of PRO40 with HEX-1, a Woronin body-specific protein. However, the integrity of Woronin bodies is not affected in mutant strains of S. macrospora and Neurospora crassa, as shown by fluorescence microscopy, sedimentation, and immunoblot analyses. We discuss the function of PRO40 in fruiting body formation.
authors.affiliation: Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, ND7/131, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Engh
authors.forename: Christian
authors.initials: C
authors.lastname: Würtz
authors.forename: Konstanze
authors.initials: K
authors.lastname: Witzel-Schlömp
authors.forename: Hai Yu
authors.initials: HY
authors.lastname: Zhang
authors.forename: Birgit
authors.initials: B
authors.lastname: Hoff
authors.forename: Minou
authors.initials: M
authors.lastname: Nowrousian
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Rottensteiner
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kück
mesh_terms: D000595:Amino Acid Sequence; D002244:Carbon; D005298:Fertility; D048690:Fruiting Bodies, Fungal / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009491:Neurospora / Q000254:growth & development; D010455:Peptides / Q000378:metabolism; D020675:Peroxisomes / Q000378:metabolism; D020161:Physical Chromosome Mapping; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020037:Sordariales / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D010455:Peptides; D012333:RNA, Messenger; D002244:Carbon