title: Evidence for three differentially regulated catalase genes in Neurospora crassa: effects of oxidative stress, heat shock, and development.
abstract: Genetic and biochemical studies demonstrated that Neurospora crassa possesses three catalases encoded by three separate structural genes. The specific activities of the three enzymes varied in response to superoxide-mediated stress, heat shock, and development. The three loci, which we designated cat-1, cat-2, and cat-3, map to the right arms of chromosomes III, VII, and III, respectively. The cat-1-encoded enzyme (designated Cat-1; estimated molecular weight, 315,000; pI 5.2) was the predominant catalase in rapid-growth mycelium, and its activity was substantially increased in paraquat-treated and heat-shocked mycelium. Cat-2 (Mw, 165,000; pI 5.4) was absent from rapid-growth mycelium but present at low levels in conidia and stationary-phase mycelium. It was the predominant catalase in extracts derived from mycelium that had been heat shocked for 2 h. Cat-3 (Mw, 340,000; pI 5.5) was the predominant catalase in extracts from mature conidia.
authors.affiliation: Department of Biology, University of New Mexico, Albuquerque 87131.
authors.forename: P
authors.initials: P
authors.lastname: Chary
authors.forename: D O
authors.initials: DO
authors.lastname: Natvig
mesh_terms: D000367:Age Factors; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D005786:Gene Expression Regulation; D005796:Genes; D005800:Genes, Fungal; D006358:Hot Temperature; D007526:Isoelectric Point; D008970:Molecular Weight; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000235:genetics* / Q000254:growth & development; D013481:Superoxides / Q000494:pharmacology*
chemical_list: D013481:Superoxides; D002374:Catalase