title: Repeat-induced point mutations in Pad-1, a putative RNA splicing factor from Neurospora crassa, confer dominant lethal effects on ascus development.
abstract: We describe the characterization of a gene, Pad-1, from Neurospora crassa which displays sequence characteristics of the RS class of hnRNA-binding proteins (hnRNP) and mRNA splicing factors. This is the first report of the isolation of a putative hnRNP gene from N. crassa. PAD-1 showed 30% identity and 57% similarity to a protein, HCC1, which was isolated using autoantibodies from patients suffering from hepatocellular carcinoma. Both HCC1 and PAD-1 show amino acid sequence similarities to the human splicing factor, U2AF65. Mutations induced in Pad-1 by repeat-induced point (RIP) mutation show dominant effects on ascus and ascospore formation, a novel phenotypic class of RIP mutants. A mutant isolated from the Pad-1 RIP cross displayed a severe vegetative growth defect and dominant effects on ascus development, indicating that Pad-1 is essential for both asexual and sexual development.
authors.affiliation: Botany Department and Biotechnology Laboratory, University of British Columbia, Vancouver, Canada.
authors.forename: G A
authors.initials: GA
authors.lastname: Kuldau
authors.forename: N B
authors.initials: NB
authors.lastname: Raju
authors.forename: N L
authors.initials: NL
authors.lastname: Glass
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005656:Fungal Proteins; D005799:Genes, Dominant; D005800:Genes, Fungal; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009492:Neurospora crassa / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics; D017354:Point Mutation / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics*; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015138:RNA, Nuclear / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics*; D017411:Ribonucleoproteins, Small Nuclear; D016415:Sequence Alignment; D000072668:Splicing Factor U2AF; D013172:Spores, Fungal / Q000502:physiology
chemical_list: D005656:Fungal Proteins; C084105:HCC1 autoantigen; D009687:Nuclear Proteins; C112587:Pad-1 protein, Neurospora crassa; D012331:RNA, Fungal; D012333:RNA, Messenger; D015138:RNA, Nuclear; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D000072668:Splicing Factor U2AF; C000607494:U2AF2 protein, human