title: Roles of Candida albicans Dfg5p and Dcw1p cell surface proteins in growth and hypha formation.
abstract: The Candida albicans cell wall participates in both growth and morphological transitions between yeast and hyphae. Our studies here focus on Dfg5p and Dcw1p, two similar proteins with features of glycosylphosphatidylinositol-linked cell surface proteins. Mutants lacking Dfg5p are defective in alkaline pH-induced hypha formation; mutants lacking Dcw1p have no detected hypha formation defect. Both homozygote-triplication tests and conditional expression strategies indicate that dfg5 and dcw1 mutations are synthetically lethal. Therefore, Dfg5p and Dcw1p share a function required for growth. Epitope-tagged Dfg5p, created through an insertional mutagenesis strategy, is found in cell membrane and cell wall extract fractions, and endoglycosidase H digestion shows that Dfg5p undergoes N-linked mannosylation. Surprisingly, Dfg5p is required for expression of the hypha-specific gene HWP1 in alkaline media. Because Dfg5p is a cell surface protein, it is poised to generate or transmit an external signal required for the program of hypha-specific gene expression.
authors.affiliation: Department of Microbiology and Institute of Cancer Research, Columbia University, New York, New York 10032, USA.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Spreghini
authors.forename: Dana A
authors.initials: DA
authors.lastname: Davis
authors.forename: Ryan
authors.initials: R
authors.lastname: Subaran
authors.forename: Michelle
authors.initials: M
authors.lastname: Kim
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Mitchell
mesh_terms: D002176:Candida albicans / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D005804:Genes, Lethal / Q000235:genetics; D025301:Hyphae / Q000235:genetics / Q000378:metabolism*; D008358:Mannose / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D005656:Fungal Proteins; C118102:HWP1 protein, Candida albicans; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D008358:Mannose