title: Regulation of cytochrome c oxidase subunit 1 (COX1) expression in Cryptococcus neoformans by temperature and host environment.
abstract: In the study of differential gene expression of Cryptococcus neoformans, a transcript of COX1 (cytochrome oxidase c subunit 1) was identified in a serotype A strain. The transcript was upregulated at 37 degrees C compared to 30 degrees C and expressed by yeasts infecting the central nervous system. Northern analysis of COX1 from the serotype A strain revealed two polycistronic transcripts, a temperature-upregulated 2.3 kb transcript and a 1.9 kb transcript that was not affected by temperature. In contrast, COX1 in a serotype D strain showed only a 1.9 kb polycistronic transcript plus a 1.6 kb monocistronic message, and temperature had no effect on the transcripts. The sequence of COX1 revealed similar coding regions between the two strains, but the serotype D strain had five introns whereas no introns were found in the serotype A strain. The serotype D strain had reduced growth rates compared to the serotype A strain at 37 degrees C, but in an AD hybrid strain the serotype D COX1 gene could support efficient high temperature growth. These studies have revealed mitochondrial molecular differences between serotype A and D strains which show evolutionary divergence. It will be important to determine whether differences in mitochondrial structure and function can influence cryptococcosis.
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Dena L
authors.initials: DL
authors.lastname: Toffaletti
authors.affiliation: Department of Biochemistry, Medical College of South Carolina, Charleston, SC 29425, USA.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Del Poeta
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Rude
authors.affiliation: Department of Genetics, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Fred
authors.initials: F
authors.lastname: Dietrich
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Perfect
mesh_terms: D003455:Cryptococcus neoformans / Q000145:classification / Q000201:enzymology* / Q000254:growth & development*; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism*; D004777:Environment; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D007621:Karyotyping; D008928:Mitochondria / Q000235:genetics; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013696:Temperature
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV