The regulation of Saccharomyces cerevisiae FLO gene expression and Ca2+-dependent flocculation by Flo8p and Mss11p

Abstract

The ability of many microorganisms to modify adhesion-related properties of their cell surface is of importance for many processes, including substrate adhesion, cell-cell adhesion, invasive growth, pathogenic behaviour and biofilm formation. In the yeast Saccharomyces cerevisiae, a group of structurally related, cell-wall associated proteins encoded by the FLO gene family are directly responsible for many of the cellular adhesion phenotypes displayed by this organism. Previous research has suggested that the differential transcription of FLO genes determines specific adhesion phenotypes. However, the transcriptional regulation of most FLO genes remains poorly understood. Here we show that the transcriptional activator Mss11p, which has previously been shown to be involved in the regulation of starch degradation, the formation of pseudohyphae and haploid invasive growth, also acts as a strong inducer of flocculation. The data indicate that Mss11p induces flocculation together with Flo8p, and that FLO1 is the dominant target gene of the two factors in this process. The deletion of MSS11 leads to a non-flocculent phenotype, and specific domains of Mss11p that are critical for the induction of flocculation are identified. The data clearly show that several essential transcription factors are shared by at least two flocculation genes that control different adhesion phenotypes.

Comparative Transcriptomic Approach To Investigate Differences in Wine Yeast Physiology and Metabolism during Fermentation

“…Flocculation was low in the EC1118 and VIN13 strains, increased in DV10, and was highest for 285 and BM45. The flocculation percentages observed are, however, all much lower than those obtained under similar conditions with laboratory yeast strains (8). Besides flocculation ability, the cell surface hydrophobicity of the various strains also differed significantly from one strain to another.…”

“…However, these genes are known to present strong strain-dependent variation in size and in their effectiveness in inducing adhesion-related phenotypes (44), and their individual expression levels may not be accurately measured in current arrays because of significant sequence homology. More interesting from a phenotypic perspective should be the expression levels of transcriptional activators that are known to control general adhesion properties such as FLO8 (8,43,44). This gene showed significantly higher expression levels during early stationary phase in the BM45 strain than the weaker-flocculating strains VIN13 and EC11118, correlating well with the observed difference in intrinsic flocculation and adhesion ability.…”

“…Although the ability of S. cerevisiae cells to adhere to other cells and to one another is a component of complex developmental processes, one of the main requirements is the expression of various FLO genes, FLO1, FLO5, FLO10, and FLO11/MUC1 (8,10,27,43). However, these genes are known to present strong strain-dependent variation in size and in their effectiveness in inducing adhesion-related phenotypes (44), and their individual expression levels may not be accurately measured in current arrays because of significant sequence homology.…”

Mss11, a Transcriptional Activator, Is Required for Hyphal Development in Candida albicans

“…In S. diastaticus, Flo8 and Mss11 bind cooperatively to the STA1 promoter and function as a heterodimer in activating STA1 expression (27). Furthermore, Mss11 is a transcription factor playing important roles in flocculation, filamentous growth, starch metabolism, and activation of gene expression in S. cerevisiae (2,19,38,51,54). To determine whether a similar molecular mechanism exists in C. albicans, we searched the NCBI database (http://www.ncbi.nlm .nih.gov/BLAST/) for the S. cerevisiae Mss11 homolog and found a C. albicans protein designated Mss11 (orf19.6309) that shares similar structural features with S. cerevisiae Mss11 (ScMss11).…”

Rare Variants in Hypermutable Genes Underlie Common Morphology and Growth Traits in WildSaccharomyces paradoxus

“…These strains formed flocs across a range of cell densities and environmental treatments ( Figure S1), in contrast to reports of condition-specific flocculation in S. cerevisiae (Smit et al 1992;Dengis et al 1995;Bayly et al 2005;Sampermans et al 2005). We also surveyed European S. paradoxus strains for invasive growth, the ability of yeast colonies to adhere to and penetrate a solid substrate (Guo et al 2000;Palecek et al 2000;Bester et al 2006). Most strains invaded a solid rich-medium agar substrate to some extent ( Figure 1B), again in contrast to the requirement for nutrient limitation often seen in S. cerevisiae (Vinod et al 2008;Zaman et al 2008).…”