title: The bacterial secondary metabolite 2,4-diacetylphloroglucinol impairs mitochondrial function and affects calcium homeostasis in Neurospora crassa.
abstract: The bacterial secondary metabolite 2,4-diacetylphloroglucinol (DAPG) is of interest as an active ingredient of biological control strains of Pseudomonas fluorescens and as a potential lead pharmaceutical molecule because of its capacity to inhibit growth of diverse microbial and non-microbial cells. The mechanism by which this occurs is unknown and in this study the filamentous fungus Neurospora crassa was used as a model to investigate the effects of DAPG on a eukaryotic cell. Colony growth, conidial germination and cell fusion assays confirmed the inhibitory nature of DAPG towards N. crassa. A number of different fluorescent dyes and fluorescent protein reporters were used to assess the effects of DAPG treatment on mitochondrial and other cellular functions. DAPG treatment led to changes in mitochondrial morphology, and rapid loss of mitochondrial membrane potential. These effects are likely to be responsible for the toxicity of DAPG. It was also found that DAPG treatment caused extracellular calcium to be taken up by conidial germlings leading to a transient increase in cytosolic free Ca(2+) with a distinct concentration dependent Ca(2+) signature.
authors.affiliation: Microbiology Department, University College Cork, Cork, Ireland.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Troppens
authors.forename: Meiling
authors.initials: M
authors.lastname: Chu
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Holcombe
authors.forename: Olive
authors.initials: O
authors.lastname: Gleeson
authors.forename: Fergal
authors.initials: F
authors.lastname: O'Gara
authors.forename: Nick D
authors.initials: ND
authors.lastname: Read
authors.forename: John P
authors.initials: JP
authors.lastname: Morrissey
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D006706:Homeostasis / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000502:physiology*; D009492:Neurospora crassa / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000378:metabolism; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development
chemical_list: D000935:Antifungal Agents; C059817:2,4-diacetylphloroglucinol; D010696:Phloroglucinol; D002118:Calcium