title: Regulation of cell-surface genes and biofilm formation by the C. albicans transcription factor Bcr1p.
abstract: The impact of many microorganisms on their environment depends upon their ability to form surface bound communities called biofilms [1]. Biofilm formation on implanted medical devices has severe consequences for human health by providing both a portal of entry and a sanctuary for invasive bacterial and fungal pathogens [1 and 2]. Biofilm regulators and adherence molecules are extensively defined for many bacterial pathogens [3, 4, and 5], but not for fungal pathogens such as Candida albicans. Elongated filaments called hyphae are a prominent feature of C. albicans biofilms, and known genes that promote biofilm formation are required for hyphal development [2, 6, 7 and 8]. From a new library of transcription-factor mutants, we identify Bcr1p, a zinc finger protein required for formation of biofilms but not hyphae. Expression analysis shows that Bcr1p activates cell-surface protein and adhesin genes, including several induced during hyphal development. BCR1 expression depends upon the hyphal regulator Tec1p. Thus, BCR1 is a downstream component of the hyphal regulatory network that couples expression of cell-surface genes to hyphal differentiation. Our results indicate that hyphal cells are specialized to present adherence molecules that support biofilm integrity.
authors.affiliation: Department of Microbiology, Columbia University, New York, NY 10032, USA.
authors.forename: Clarissa J
authors.initials: CJ
authors.lastname: Nobile
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Mitchell
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D002176:Candida albicans / Q000235:genetics / Q000502:physiology*; D002462:Cell Membrane / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers / Q000235:genetics
chemical_list: C113620:ALS3 protein, Candida albicans; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C118102:HWP1 protein, Candida albicans; D008562:Membrane Glycoproteins; C489432:TEC1 protein, Candida albicans; D014157:Transcription Factors; D049452:Green Fluorescent Proteins