title: Influence of histatin 5 on Candida albicans mitochondrial protein expression assessed by quantitative mass spectrometry.
abstract: Individual aspects of the mode of action of histatin 5, a human salivary antifungal protein, have been partially elucidated, but the mechanism likely involves a complex set of events that have not been characterized. Previous evidence points toward histatin-induced alterations in mitochondrial function. The purpose of the present study was to verify and quantify changes in the mitochondrial proteome of Candida albicans treated with histatin 5. Cell killing was determined by plating and differential protein expression levels in the mitochondrial samples were determined by quantitative proteomics approaches employing mTRAQ and ICAT labeling and Western blotting. Relative quantitation ratios were established for 144 different proteins. Up-regulated mitochondrial proteins were predominantly involved in genome maintenance and gene expression, whereas proteins that constitute the respiratory enzyme complexes were mostly down-regulated. The differential expression of ATP synthase gamma chain and elongation factor 1-alpha were confirmed by Western blotting by comparison to levels of cytochrome c which were unchanged upon histatin treatment. The mTRAQ and ICAT proteomics results suggest that key steps in the histatin 5 antifungal mechanism involve a bioenergetic collapse of C. albicans, caused essentially by a decrease in mitochondrial ATP synthesis.
authors.affiliation: Department of Periodontology and Oral Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, Massachusetts 02118, USA.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Komatsu
authors.forename: Erdjan
authors.initials: E
authors.lastname: Salih
authors.forename: Eva J
authors.initials: EJ
authors.lastname: Helmerhorst
authors.forename: Gwynneth D
authors.initials: GD
authors.lastname: Offner
authors.forename: Frank G
authors.initials: FG
authors.lastname: Oppenheim
mesh_terms: D000935:Antifungal Agents; D015153:Blotting, Western; D002176:Candida albicans / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D005656:Fungal Proteins / Q000032:analysis / Q000378:metabolism; D054808:Histatins / Q000494:pharmacology*; D006801:Humans; D007553:Isotope Labeling; D013058:Mass Spectrometry; D024101:Mitochondrial Proteins / Q000378:metabolism*; D020543:Proteome / Q000032:analysis* / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; C068075:HTN3 protein, human; D054808:Histatins; D024101:Mitochondrial Proteins; D020543:Proteome