A flucytosine-responsive Mbp1/Swi4-like protein, Mbs1, plays pleiotropic roles in antifungal drug resistance, stress response, and virulence of Cryptococcus neoformans.

Journal Article (Journal Article)

Cryptococcosis, caused by the basidiomycetous fungus Cryptococcus neoformans, is responsible for more than 600,000 deaths annually in AIDS patients. Flucytosine is one of the most commonly used antifungal drugs for its treatment, but its resistance and regulatory mechanisms have never been investigated at the genome scale in C. neoformans. In the present study, we performed comparative transcriptome analysis by employing two-component system mutants (tco1Δ and tco2Δ) exhibiting opposing flucytosine susceptibility. As a result, a total of 177 flucytosine-responsive genes were identified, and many of them were found to be regulated by Tco1 or Tco2. Among these, we discovered an APSES-like transcription factor, Mbs1 (Mbp1- and Swi4-like protein 1). Expression analysis revealed that MBS1 was regulated in response to flucytosine in a Tco2/Hog1-dependent manner. Supporting this, C. neoformans with the deletion of MBS1 exhibited increased susceptibility to flucytosine. Intriguingly, Mbs1 played pleiotropic roles in diverse cellular processes of C. neoformans. Mbs1 positively regulated ergosterol biosynthesis and thereby affected polyene and azole drug susceptibility. Mbs1 was also involved in genotoxic and oxidative stress responses. Furthermore, Mbs1 promoted production of melanin and capsule and thereby was required for full virulence of C. neoformans. In conclusion, Mbs1 is considered to be a novel antifungal therapeutic target for treatment of cryptococcosis.

Full Text

Duke Authors

Cited Authors

  • Song, M-H; Lee, J-W; Kim, MS; Yoon, J-K; White, TC; Floyd, A; Heitman, J; Strain, AK; Nielsen, JN; Nielsen, K; Bahn, Y-S

Published Date

  • January 2012

Published In

Volume / Issue

  • 11 / 1

Start / End Page

  • 53 - 67

PubMed ID

  • 22080454

Pubmed Central ID

  • PMC3255937

Electronic International Standard Serial Number (EISSN)

  • 1535-9786

Digital Object Identifier (DOI)

  • 10.1128/EC.05236-11


  • eng

Conference Location

  • United States