title: Proteomic analysis of cytosolic proteins associated with petite mutations in Candida glabrata.
abstract: The incidence of superficial or deep-seated infections due to Candida glabrata has increased markedly, probably because of the low intrinsic susceptibility of this microorganism to azole antifungals and its relatively high propensity to acquire azole resistance. To determine changes in the C. glabrata proteome associated with petite mutations, cytosolic extracts from an azole-resistant petite mutant of C. glabrata induced by exposure to ethidium bromide, and from its azole-susceptible parent isolate were compared by two-dimensional polyacrylamide gel electrophoresis. Proteins of interest were identified by peptide mass fingerprinting or sequence tagging using a matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometer. Tryptic peptides from a total of 160 Coomassie-positive spots were analyzed for each strain. Sixty-five different proteins were identified in the cytosolic extracts of the parent strain and 58 in the petite mutant. Among the proteins identified, 10 were higher in the mutant strain, whereas 23 were lower compared to the parent strain. The results revealed a significant decrease in the enzymes associated with the metabolic rate of mutant cells such as aconitase, transaldolase, and pyruvate kinase, and changes in the levels of specific heat shock proteins. Moreover, transketolase, aconitase and catalase activity measurements decreased significantly in the ethidium bromide-induced petite mutant. These data may be useful for designing experiments to obtain a better understanding of the nuclear response to impairment of mitochondrial function associated with this mutation in C. glabrata.
authors.affiliation: Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, RJ, Brasil. carlapenha@hotmail.com
authors.forename: C V
authors.initials: CV
authors.lastname: Loureiro Y Penha
authors.forename: P H B
authors.initials: PH
authors.lastname: Kubitschek
authors.forename: G
authors.initials: G
authors.lastname: Larcher
authors.forename: J
authors.initials: J
authors.lastname: Perales
authors.forename: I
authors.initials: I
authors.lastname: Rodriguez León
authors.forename: L M
authors.initials: LM
authors.lastname: Lopes-Bezerra
authors.forename: J P
authors.initials: JP
authors.lastname: Bouchara
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D001393:Azoles / Q000494:pharmacology; D041221:Candida glabrata / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D005656:Fungal Proteins / Q000032:analysis* / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D009154:Mutation / Q000235:genetics*; D020543:Proteome / Q000032:analysis* / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000935:Antifungal Agents; D001393:Azoles; D005656:Fungal Proteins; D020543:Proteome