title: β(1,3)-glucan synthase complex from Alternaria infectoria, a rare dematiaceous human pathogen.
abstract: The fungal cell wall polymer β-(1,3)-D-glucan is synthesized by the enzyme β-(1,3)- D-glucan synthase that is a complex composed of at least two proteins, Rho1p and Fks1p. Here, we report the nucleotide sequence of a single FKS gene and of the regulatory unit, RHO1 from the dematiaceous pathogenic fungus Alternaria infectoria. The predicted AiFks and AiRho share, respectively, 93% and 100% identity with that of Drechslera tritici-repentis. We also report that the sensitivity to caspofungin of eight different A. infectoria clinical strains is similar, with a MIC > 32 µg/ml and a MEC of 1 µg/ml, except for one strain which had a MEC of 1.4 µg/ml. This same strain exhibited one substitution at the hot spot 2, S1405A, compatible with less susceptible phenotypes, with the other seven strains having no mutations in either hot spot 1 or 2. The relative quantification of the expression of AiFKS and of AiRHO demonstrated a decrease in response to an exposure to caspofungin at 0.5 µg/ml.
authors.affiliation: CNC-Centre for Neurosciences and Cell Biology, University of Coimbra, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Anjos
authors.forename: Chantal
authors.initials: C
authors.lastname: Fernandes
authors.forename: Branca M A
authors.initials: BM
authors.lastname: Silva
authors.forename: Célia
authors.initials: C
authors.lastname: Quintas
authors.forename: Alexandra
authors.initials: A
authors.lastname: Abrunheiro
authors.forename: Neil A R
authors.initials: NA
authors.lastname: Gow
authors.forename: Teresa
authors.initials: T
authors.lastname: Gonçalves
mesh_terms: D000528:Alternaria / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D019943:Amino Acid Substitution; D000935:Antifungal Agents / Q000494:pharmacology; D000077336:Caspofungin; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D054714:Echinocandins / Q000494:pharmacology; D005964:Glucosyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D055666:Lipopeptides; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010802:Phylogeny; D017354:Point Mutation; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D047071:beta-Glucans / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D004271:DNA, Fungal; D054714:Echinocandins; D055666:Lipopeptides; D047071:beta-Glucans; C033363:beta-1,3-glucan; D005964:Glucosyltransferases; C020570:1,3-beta-glucan synthase; D000077336:Caspofungin