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.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Candida albicans / genetics
-
Candida albicans / growth & development*
-
Candida albicans / metabolism*
-
Cell Wall / genetics
-
Cell Wall / metabolism*
-
Cells, Cultured
-
DNA, Complementary / analysis
-
DNA, Complementary / genetics
-
Fungal Proteins / genetics
-
Fungal Proteins / isolation & purification
-
Fungal Proteins / metabolism
-
Fungal Proteins / physiology*
-
Gene Expression Regulation, Fungal / genetics
-
Genes, Lethal / genetics
-
Hyphae / genetics
-
Hyphae / metabolism*
-
Mannose / metabolism
-
Membrane Glycoproteins / genetics
-
Membrane Glycoproteins / isolation & purification
-
Membrane Glycoproteins / metabolism
-
Membrane Glycoproteins / physiology
-
Membrane Proteins / genetics
-
Membrane Proteins / isolation & purification
-
Membrane Proteins / physiology*
-
Molecular Sequence Data
-
Mutation / genetics
-
Sequence Homology, Amino Acid
-
Sequence Homology, Nucleic Acid
-
Signal Transduction / genetics
Substances
-
DNA, Complementary
-
Fungal Proteins
-
HWP1 protein, Candida albicans
-
Membrane Glycoproteins
-
Membrane Proteins
-
Mannose