Marine antifungal theonellamides target 3beta-hydroxysterol to activate Rho1 signaling.

Linking bioactive compounds to their cellular targets is a central challenge in chemical biology. Here we report the mode of action of theonellamides, bicyclic peptides derived from marine sponges. We generated a chemical-genomic profile of theonellamide F using a collection of fission yeast strains in which each open reading frame (ORF) is expressed under the control of an inducible promoter. Clustering analysis of the Gene Ontology (GO) terms associated with the genes that alter drug sensitivity suggested a mechanistic link between theonellamide and 1,3-beta-D-glucan synthesis. Indeed, theonellamide F induced overproduction of 1,3-beta-D-glucan in a Rho1-dependent manner. Subcellular localization and in vitro binding assays using a fluorescent theonellamide derivative revealed that theonellamides specifically bind to 3beta-hydroxysterols, including ergosterol, and cause membrane damage. The biological activity of theonellamides was alleviated in mutants defective in ergosterol biosynthesis. Theonellamides thus represent a new class of sterol-binding molecules that induce membrane damage and activate Rho1-mediated 1,3-beta-D-glucan synthesis.
AuthorsShinichi Nishimura, Yuko Arita, Miyuki Honda, Kunihiko Iwamoto, Akihisa Matsuyama, Atsuko Shirai, Hisashi Kawasaki, Hideaki Kakeya, Toshihide Kobayashi, Shigeki Matsunaga, Minoru Yoshida
JournalNature chemical biology (Nat Chem Biol) Vol. 6 Issue 7 Pg. 519-26 (Jul 2010) ISSN: 1552-4469 [Electronic] United States
PMID20543850 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
Chemical References
  • Antifungal Agents
  • Echinocandins
  • Hydroxysteroids
  • Lipopeptides
  • Peptides, Cyclic
  • Schizosaccharomyces pombe Proteins
  • theonellamide F
  • rho GTP-Binding Proteins
  • rho1 protein, S pombe
  • micafungin
  • Animals
  • Antifungal Agents (chemistry, pharmacology)
  • Drug Evaluation, Preclinical
  • Echinocandins (pharmacology)
  • Gene Expression Profiling
  • Hydroxysteroids (metabolism)
  • Lipopeptides (pharmacology)
  • Marine Biology
  • Molecular Structure
  • Peptides, Cyclic (pharmacology)
  • Schizosaccharomyces (cytology, drug effects)
  • Schizosaccharomyces pombe Proteins (metabolism)
  • Theonella (chemistry)
  • rho GTP-Binding Proteins (metabolism)

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