Anne Dranginis, Ph.D.
In our laboratory we study gene regulation using the model
eukaryote Saccharomyces cerevisiae, the bread yeast. Yeast are an
excellent model system because of the extremely powerful genetic
tools available for use with this organism. Precise mutations may
be introduced anywhere in the yeast genome, for example, and genes
can be removed or replaced easily. Over 40% of cloned human genes
have proven to have homologs in yeast.
We discovered and characterized a gene that we named FLO11,
which proved to encode an important cell wall protein in yeast. The
protein product of FLO11 is a cell surface molecule that causes
adhesion to substrates and to other cells. Flo11 is required for
several types of development in yeast. The formation of
pseudohyphae (long filamentous branched chains of cells) requires
Flo11, as does invasive behavior of yeast cells.
Filament formation and invasion are important characteristics of
pathogenic fungi. Although Saccharomyces cerevisiae is not a
pathogenic fungus, it is a good model for the study of many
disease-causing fungi, such as Candida albicans. There is a great
need for safer, more effective anti-fungal therapies. Flo11 is a
promising target for such therapies since it is extracellular,
unique to fungi, and required for filament formation.
Currently we are investigating regulation of FLO11 gene
expression as well as the function of the protein. We are also
investigating FLO11 homologs in the pathogenic yeast Candida
Lo, W.-S. and Dranginis, A.M. (1998). The cell surface flocculin
Flo11 is required for pseudohyphae formation and invasion by S.
cerevisiae. Molec. Biol. Cell 9: 161-171.
Lo, W.-S., Raitses, E. I., and Dranginis, A.M. (1997)
Development of pseudohyphae by embedded haploid and diploid yeast.
Curr. Genet. 32: 197-202.
Lo, W.-S. and Dranginis, A.M. (1996). FLO11, a yeast gene
related to the STA genes, encodes a novel cell surface flocculin.
J. Bacteriol. 178: 7144-7151.