Differential profiles of soluble proteins during the initiation of morphogenesis in Candida albicans.
Candida albicans is a dimorphic fungus that can grow either as yeast or as mycelia. The mycelial form may be required for tissue penetration and therefore may have a role in pathogenesis. The protein profiles of the cell-free S100 fraction from budding yeast cells and germ tube-forming cells (an early stage of the transition between yeast and mycelia) were evaluated using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Yeast growth or germ tube formation was induced in carbon-starved cells at 37 degrees C by either glucose, galactose or N-acetylglucosamine at pH 4.5 or pH 6.7. More than 400 constitutively synthesised polypeptides were identified on 2-D PAGE by silver staining. A few polypeptides which seem to reflect the release from carbon starvation were detected, but no polypeptides unique to either morphology were observed. Fractionation of S100 preparations by polyethylenimine or heparin-agarose affinity chromatography, which have been used to detect DNA-binding proteins, revealed several proteins that were synthesised on the resumption of cell growth or in response to pH difference. Heparin-agarose also bound novel polypeptides in the size range 130-200 kDa that were preferentially synthesised in germ tube-forming cells. These results suggest that any protein factors that might exert a regulatory role early in germ tube formation are of low abundance, and that a minor group of soluble proteins involved in C. albicans morphogenesis may be differentially synthesised.
Niimi
M
M
Experimental Oral Biology Laboratory, Department of Oral Biology and Oral Pathology, School of Dentistry, University of Otago, P.O. Box 647, Dunedin, New Zealand. masa.niimi@stonebow.otago.ac.nz
Shepherd
M G
MG
Monk
B C
BC
D000117:Acetylglucosamine / Q000378:metabolism; D000645:Ammonium Sulfate / Q000494:pharmacology; D002176:Candida albicans / Q000378:metabolism* / Q000472:pathogenicity; D002454:Cell Differentiation / Q000235:genetics; D002458:Cell Fractionation; D002846:Chromatography, Affinity; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009024:Morphogenesis / Q000502:physiology*; D010455:Peptides / Q000737:chemistry; D011094:Polyethyleneimine / Q000378:metabolism
D005656:Fungal Proteins; D010455:Peptides; D011094:Polyethyleneimine; D005947:Glucose; D000645:Ammonium Sulfate; D000117:Acetylglucosamine