The Cryptococcus neoformans GAL7 gene and its use as an inducible promoter

Brian L. Wickes, Jeffrey C. Edman

Research output: Contribution to journalArticlepeer-review

59 Scopus citations


A Cryptococcus neoformans galactose auxotroph was created by ultraviolet light mutagenesis and complemented with a C. neoformans genomic library. The translated sequence of the complementing DNA revealed a high degree of simlarity to a number of UDP glucose‐D‐gatactose‐1‐phosphate uridylyitransferases. Expression of C. neoformans GAL7 mRNA followed a pattern similar to Saccharomyces cerevisiae expression; it was first observed within 2.5 min of induction and fully induced by 30 min. The gene was completely repressed in the presence of glucose. The GAL7 promoter was isolated and used to construct a promoter cassette. Two genes were tested in this cassette for galactose regulation by creating GAL7 promoter fusions with their coding regions. MFα, which encodes a pheromone, was found to produce filaments only in transformants that were induced by galactose. A second gene, β‐glucuronidase (gusA), which is a commonly used reporter gene, was tested and also found to be expressed. When the GAL7 p::GUS fusion was used to quantify inducibitity of the GAL7 promoter, the level of enzyme activity was at least 500‐fold greater for cells grown in galactose than for cells grown in glucose. The GAL7 promoter is the first inducible promoter characterized in C neoformans and the GUS gene is the first heterologous gene shown to be expressed in this yeast pathogen.

Original languageEnglish (US)
Pages (from-to)1099-1109
Number of pages11
JournalMolecular Microbiology
Issue number6
StatePublished - Jun 1995
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Biology
  • Microbiology


Dive into the research topics of 'The Cryptococcus neoformans GAL7 gene and its use as an inducible promoter'. Together they form a unique fingerprint.

Cite this