title: csmA, a gene encoding a class V chitin synthase with a myosin motor-like domain of Aspergillus nidulans, is translated as a single polypeptide and regulated in response to osmotic conditions.
abstract: The csmA gene of Aspergillus nidulans encodes a polypeptide that consists of an N-terminal myosin motor-like domain and a C-terminal chitin synthase domain. csmA null mutants showed marked abnormalities in polarized growth, hyphal wall integrity, and conidiophore development. Furthermore, the growth of the csmA null mutants was sensitive to low osmotic conditions. In an effort to investigate the intracellular behavior of the csmA product (CsmA) and the regulation of its production, we constructed strains that produced CsmA tagged with nine repeats of the hemagglutinin A (HA) epitope at its COOH terminus (CsmA-HA) instead of CsmA. Western blot analysis with anti-HA antibody showed that the entire coding region of csmA was translated as a single polypeptide with an approximate molecular mass of 210kDa. CsmA-HA was produced during vegetative growth; however, its yield was significantly reduced under high osmotic conditions, suggesting that the role of CsmA in growth and morphogenesis is particularly important under low osmotic conditions.
authors.affiliation: Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. ahhoriu@mail.ecc.u-tokyo.ac.jp
authors.forename: Norio
authors.initials: N
authors.lastname: Takeshita
authors.forename: Akinori
authors.initials: A
authors.lastname: Ohta
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Horiuchi
mesh_terms: D001233:Aspergillus nidulans / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence; D002687:Chitin Synthase / Q000096:biosynthesis* / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006388:Hemagglutinins / Q000235:genetics; D007700:Kinetics; D037102:Lectins; D020409:Molecular Motor Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D009218:Myosins / Q000737:chemistry; D009994:Osmolar Concentration; D010452:Peptide Biosynthesis; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D012331:RNA, Fungal / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D006388:Hemagglutinins; D037102:Lectins; D020409:Molecular Motor Proteins; D012331:RNA, Fungal; D011993:Recombinant Fusion Proteins; C114923:hemagglutinin A, Porphyromonas gingivalis; D002687:Chitin Synthase; D009218:Myosins