Wall mannoproteins in cells from colonial phenotypic variants of Candida albicans

Abstract

Candida albicans ATCC 26555 switched at high frequency (10-l to between several phenotypes identified by colony morphology on a defined mineral amino-acid-containing agar medium supplemented with arginine and zinc (LAZ medium). When cells taken from colonies exhibiting distinct morphologies were plated directly onto LAZ agar, spontaneous conversion to all the variant phenotypes occurred at combined frequencies of 2-1 x 10-l to xHowever, when cells taken from the different colonial phenotypes were plated directly onto an undefined medium (yeast extract/peptone/dextrose; YPD medium), or first incubated in liquid YPD medium and then cloned on YPD agar, all colonies observed exhibited the same phenotype (smooth-white). When cells from the smooth-white colonies were plated as clones on LAZ agar, the original switch phenotype reappeared. These results suggest that environmental conditions such as the growth medium (and possibly the temperature) influence switching by suppressing phenotype expression, but have no effect on genotype. The variant colony morphologies also appeared to be associated with differences in the relative proportions of yeast and mycelial cells. Zymolyase digests of wall preparations obtained from cells belonging to different colonial phenotypes were analysed by SDS-PAGE. After blotting to nitrocellulose paper, the mannoproteins were stained with Concanavalin A, with a polyclonal antiserum enriched in antibodies against mycelium-specific wall components, and with a monoclonal antibody raised against a high-molecular-mass mannoprotein band (260 kDa) specific to the walls of mycelial cells. The results suggest that phenotypic switching might be associated with changes in the degree of glycosylation in high-molecular-mass mannoproteins, or in the way these mannoproteins are bound to other cell wall components.

Control of Candida albicans Metabolism and Biofilm Formation by Pseudomonas aeruginosa Phenazines

“…C. albicans hyphal growth has been associated with both wrinkled colony morphology and biofilm formation on plastic surfaces (5, 37). We found that wrinkled colonies, formed upon growth on medium with GlcNAc at 37°C, exhibited some biofilm-associated characteristics, including cells in hyphal, pseudohyphal, and yeast morphologies that remained associated with one another even upon suspension in liquid (Fig.…”

β-1,2 Oligomannose Adhesin Epitopes Are Widely Distributed over the Different Families of Candida albicans Cell Wall Mannoproteins and Are Associated through both N- and O-Glycosylation Processes

“…To map ␤-Man epitopes for the different CWMP families, we slightly modified the protocols generally used (10,48) to sequentially release CWMPs. ConA, a lectin specific for terminal ␣-D-mannosyl and ␣-D-glucosyl residues and widely used to detect CWMPs (1,26,39), served as a systematic control in this study. As one of the aims of this study was to compare the well-defined PPM to other CWMPs, it was important to release noncovalently bound proteins, like PPM, without detergents, even at a low concentration, to avoid any contamination with covalently bound mannoproteins.…”

Redox-driven regulation of microbial community morphogenesis

“…The wrinkled structures of rugose colonies and pellicles have strikingly similar appearances in phylogenetically disparate organisms. Wrinkle-forming organisms that have become models for the study of biofilm morphogenesis include representatives from the genera Bacillus [10–14], Candida [15,16], Escherichia [17,18], Pseudomonas [19–21], Rhodospirillum [22], Saccharomyces [23–25], Salmonella [26], Serratia [27], Vibrio [28,29] and members of the phylum Actinobacteria [30,31] (Figure 1). The extent of wrinkling varies widely between isolates, even within the same species, and is condition-dependent.…”