GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:17921350

From GONUTS
Jump to: navigation, search
Citation

Douglas, LM, Li, L, Yang, Y and Dranginis, AM (2007) Expression and characterization of the flocculin Flo11/Muc1, a Saccharomyces cerevisiae mannoprotein with homotypic properties of adhesion. Eukaryotic Cell 6:2214-21

Abstract

The Flo11/Muc1 flocculin has diverse phenotypic effects. Saccharomyces cerevisiae cells of strain background Sigma1278b require Flo11p to form pseudohyphae, invade agar, adhere to plastic, and develop biofilms, but they do not flocculate. We show that S. cerevisiae var. diastaticus strains, on the other hand, exhibit Flo11-dependent flocculation and biofilm formation but do not invade agar or form pseudohyphae. In order to study the nature of the Flo11p proteins produced by these two types of strains, we examined secreted Flo11p, encoded by a plasmid-borne gene, in which the glycosylphosphatidylinositol anchor sequences had been replaced by a histidine tag. A protein of approximately 196 kDa was secreted from both strains, which upon purification and concentration, aggregated into a form with a very high molecular mass. When secreted Flo11p was covalently attached to microscopic beads, it conferred the ability to specifically bind to S. cerevisiae var. diastaticus cells, which flocculate, but not to Sigma1278b cells, which do not flocculate. This was true for the 196-kDa form as well as the high-molecular-weight form of Flo11p, regardless of the strain source. The coated beads bound to S. cerevisiae var. diastaticus cells expressing FLO11 and failed to bind to cells with a deletion of FLO11, demonstrating a homotypic adhesive mechanism. Flo11p was shown to be a mannoprotein. Bead-to-cell adhesion was inhibited by mannose, which also inhibits Flo11-dependent flocculation in vivo, further suggesting that this in vitro system is a useful model for the study of fungal adhesion.

Links

PubMed PMC2168249 Online version:10.1128/EC.00284-06

Keywords

Cell Adhesion; Cell Wall/metabolism; Gene Deletion; Gene Expression Regulation, Fungal; Genes, Fungal; Glycosylphosphatidylinositols/metabolism; Mannose/chemistry; Membrane Glycoproteins/chemistry; Membrane Proteins/chemistry; Membrane Proteins/metabolism; Membrane Proteins/physiology; Models, Biological; Phenotype; Plasmids/metabolism; RNA, Fungal; Saccharomyces cerevisiae/metabolism; Saccharomyces cerevisiae Proteins/metabolism; Saccharomyces cerevisiae Proteins/physiology

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

YEAST:MUC1

GO:0044409: entry into host

ECO:0000315:

P

Figure 1B showed the sigma1278b strain plated onto agar before and after washing. The WT could grow into the agar while the flo11 knockout could not

complete
CACAO 9937

YEAST:MUC1

GO:0000128: flocculation

ECO:0000315:

P

Figure 1A: Flocculation assay tests whether or not the cells aggregate together and drop to the bottom of the tube. The yeast does flocculate in the WT as the cells collect at the bottom. The knockout stays cloudy in the entire solution for the whole time.

complete
CACAO 9938

YEAST:MUC1

GO:0043708: cell adhesion involved in biofilm formation

ECO:0000315:

P

Figure 1D: Adherence assay. Growing strain on plastic tests biofilm formation capabilities. There is growth seen on the WT plate but not with the knockout.

complete
CACAO 9939

YEAST:MUC1

GO:0016337: cell-cell adhesion

ECO:0000315:

P

Figure 4 - Bead adhesion assay. Beads coated with the cells are placed on the plate to test cell-to-cell adhesion. In the WT, the growth is focused around the beads (black dots), while the growth in the knockout is not focused around the beads and is spread out around the plate.

complete
CACAO 9940

YEAST:MUC1

GO:0030447: response to nitrate starvation

ECO:0000315:

P

Figure 1C: Pictures of yeast plated. FLO11 gene controls hyphae (filaments) formation. WT grows hyphae in order to find more nutrients, while the knockout does not.

complete
CACAO 9941

See also

References

See Help:References for how to manage references in GONUTS.