title: APSES proteins regulate morphogenesis and metabolism in Candida albicans.
abstract: Fungal APSES proteins regulate morphogenetic processes, including filamentation and differentiation. The human fungal pathogen Candida albicans contains two APSES proteins: the regulator Efg1p and its homologue Efh1p, described here. Overexpression of EFG1 or EFH1 led to similar phenotypes, including pseudohypha formation and opaque-white switching. An efh1 deletion generated no phenotype under most conditions but caused hyperfilamentation in an efg1 background under embedded or hypoxic conditions. This suggests cooperation of these APSES proteins in the suppression of an alternative morphogenetic signaling pathway. Genome-wide transcriptional profiling revealed that EFG1 and EFH1 regulate partially overlapping sets of genes associated with filament formation. Unexpectedly, Efg1p not only regulates genes involved in morphogenesis but also strongly influences the expression of metabolic genes, inducing glycolytic genes and repressing genes essential for oxidative metabolism. Using one- and two-hybrid assays, we further demonstrate that Efg1p is a repressor, whereas Efh1p is an activator of gene expression. Overall, the results suggest that Efh1p supports the regulatory functions of the primary regulator, Efg1p, and indicate a dual role for these APSES proteins in the regulation of fungal morphogenesis and metabolism.
authors.affiliation: Institut für Mikrobiologie, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Doedt
authors.forename: Shankarling
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Dirk P
authors.initials: DP
authors.lastname: Bockmühl
authors.forename: Bernd
authors.initials: B
authors.lastname: Tebarth
authors.forename: Christian
authors.initials: C
authors.lastname: Stempel
authors.forename: Claire L
authors.initials: CL
authors.lastname: Russell
authors.forename: Alistair J P
authors.initials: AJ
authors.lastname: Brown
authors.forename: Joachim F
authors.initials: JF
authors.lastname: Ernst
mesh_terms: D000595:Amino Acid Sequence; D002176:Candida albicans / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D002952:Citric Acid Cycle / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D006019:Glycolysis / Q000235:genetics; D025301:Hyphae / Q000166:cytology; D008969:Molecular Sequence Data; D009024:Morphogenesis; D020411:Oligonucleotide Array Sequence Analysis; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D004268:DNA-Binding Proteins; C121438:EFG1 protein, Candida albicans; D005656:Fungal Proteins; D014157:Transcription Factors