Differential profiles of soluble proteins during the initiation of morphogenesis in Candida albicans
- PDF / 439,900 Bytes
- 9 Pages / 595 x 842 pts (A4) Page_size
- 91 Downloads / 188 Views
© Springer-Verlag 1996
O R I G I N A L PA P E R
Masakazu Niimi · Maxwell G. Shepherd · Brian C. Monk
Differential profiles of soluble proteins during the initiation of morphogenesis in Candida albicans
Received: 11 March 1996 / Accepted: 10 July 1996
Abstract 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° 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. Key words Candida albicans · Morphogenesis · Protein profiles · 2-D PAGE Abbreviations PEI polyethylenimine · S100 fraction supernatant from centrifugation of cell-free extract at
M. Niimi (Y) · M. G. Shepherd · B. C. Monk Experimental Oral Biology Laboratory, Department of Oral Biology and Oral Pathology, School of Dentistry, University of Otago, P.O. Box 647, Dunedin, New Zealand Tel. +64-3-479 7080; Fax +64-3-479 0673 e-mail: [email protected]
100,000 × g for 45 min · T0, T1 and T2 S100 fractions prepared immediately, 1 h and 2 h after induction of morphogenesis, respectively · GlcNAc N-acetylglucosamine
Introduction Candida albicans is a commensal of the human oral cavity, the gastrointestinal tract and the vaginal tract. It is the most common opportunistic fungal pathogen that causes superficial infection in these sites (Cannon et al. 1995). C. albicans also causes systemic or life-threatening disseminated candidosis in immuno-compromised hosts such as patients with cancer or AIDS or people who have been treated for prolonged periods with immunosuppressive agents (Bodey 1988; Coleman et al. 1993). The ability of C. albicans cells to infect host tissues has variously been attributed to adhesion, dimorphic transition, secretion of hydrolytic enzymes (including pr
Data Loading...
