title: Functional analysis of a tannic-acid-inducible and hypoviral-regulated small heat-shock protein Hsp24 from the chestnut blight fungus Cryphonectria parasitica.
abstract: A small heat-shock protein gene, CpHsp24, of Cryphonectria parasitica was selected based on its expression pattern, which showed that it was tannic acid inducible and that its induction was severely hampered by a hypovirus. The predicted protein sequence of CpHsp24 consisted of a hallmark α-crystalline domain flanked by a variable N-terminal and a short C-terminal region. Disruption of CpHsp24 resulted in a slow growth rate under standard growth conditions. The CpHsp24-null mutant showed enhanced sensitivity to heat shock, which was consistent with Northern and Western analyses displaying the heat-shock induction of the CpHsp24 gene and protein, respectively. Virulence tests on the excised bark revealed a severe decrease in the necrotic area of the CpHsp24-null mutant. When the hypovirus was transferred, virus-containing CpHsp24-null progeny displayed severely retarded growth patterns with hypovirulent characteristics of reduced pigmentation and sporulation. Because the tannic-acid-inducible and hypoviral-suppressible expression and the severely impaired virulence are also characteristics of the laccase3 gene (lac3), lac3 expression in the CpHsp24-null mutant was also examined. The resulting lac3 induction was severely affected in the CpHsp24-null mutant, suggesting that CpHsp24 is important for lac3 induction and that CpHsp24 may act as a molecular chaperone for the lac3 protein.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Baek
authors.forename: Jin-Ah
authors.initials: JA
authors.lastname: Park
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Kim
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Oh
authors.forename: Seung-Moon
authors.initials: SM
authors.lastname: Park
authors.forename: Dae-Hyuk
authors.initials: DH
authors.lastname: Kim
mesh_terms: D001203:Ascomycota / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D029785:Cyperaceae / Q000382:microbiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D050888:Heat-Shock Proteins, Small / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D042845:Laccase / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D024301:Plant Bark / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology*; D017434:Protein Structure, Tertiary; D012328:RNA Viruses / Q000502:physiology; D017384:Sequence Deletion; D013312:Stress, Physiological; D013634:Tannins / Q000494:pharmacology*; D014197:Trees; D014774:Virulence
chemical_list: D005656:Fungal Proteins; D050888:Heat-Shock Proteins, Small; D013634:Tannins; D042845:Laccase