Chemogenomic profiling in yeast reveals antifungal mode-of-action of polyene macrolactam auroramycin

PLoS One. 2019 Jun 10;14(6):e0218189. doi: 10.1371/journal.pone.0218189. eCollection 2019.

Abstract

In this study, we report antifungal activity of auroramycin against Candida albicans, Candida tropicalis, and Cryptococcus neoformans. Auroramycin, a potent antimicrobial doubly glycosylated 24-membered polyene macrolactam, was previously isolated and characterized, following CRISPR-Cas9 mediated activation of a silent polyketide synthase biosynthetic gene cluster in Streptomyces rosesporous NRRL 15998. Chemogenomic profiling of auroramycin in yeast has linked its antifungal bioactivity to vacuolar transport and membrane organization. This was verified by disruption of vacuolar structure and membrane integrity of yeast cells with auroramycin treatment. Addition of salt but not sorbitol to the medium rescued the growth of auroramycin-treated yeast cells suggesting that auroramycin causes ionic stress. Furthermore, auroramycin caused hyperpolarization of the yeast plasma membrane and displayed a synergistic interaction with cationic hygromycin. Our data strongly suggest that auroramycin inhibits yeast cells by causing leakage of cations from the cytoplasm. Thus, auroramycin's mode-of-action is distinct from known antifungal polyenes, reinforcing the importance of natural products in the discovery of new anti-infectives.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antifungal Agents / pharmacology*
  • Candida albicans / drug effects
  • Candida tropicalis / drug effects
  • Cations / metabolism
  • Cryptococcus neoformans / drug effects
  • Cytoplasm / metabolism
  • Lactams, Macrocyclic / pharmacology*
  • Polyenes / pharmacology*
  • Vacuoles / metabolism
  • Yeasts / drug effects*

Substances

  • Antifungal Agents
  • Cations
  • Lactams, Macrocyclic
  • Polyenes

Grants and funding

Funded by FTW. NRF2013-THE001-094. National Research Foundation. https://www.nrf.gov.sg/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.