Regulation of cytochrome c oxidase subunit 1 (COX1) expression in Cryptococcus neoformans by temperature and host environment

Microbiology. 2003 Apr;149(Pt 4):1041-1049. doi: 10.1099/mic.0.26021-0.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cryptococcus neoformans / classification
  • Cryptococcus neoformans / enzymology*
  • Cryptococcus neoformans / growth & development*
  • DNA, Mitochondrial / genetics
  • Electron Transport Complex IV / genetics
  • Electron Transport Complex IV / metabolism*
  • Environment*
  • Gene Expression Regulation, Fungal*
  • Humans
  • Karyotyping
  • Mitochondria / genetics
  • Molecular Sequence Data
  • Sequence Analysis, DNA
  • Serotyping
  • Temperature*


  • DNA, Mitochondrial
  • Electron Transport Complex IV

Associated data

  • GENBANK/AY101381