Depression of Saccharomyces cerevisiae invasive growth on non‐glucose carbon sources requires the Snf1 kinase

Abstract

Haploid Saccharomyces cerevisiae cells growing on media lacking glucose but containing high concentrations of carbon sources such as fructose, galactose, raffinose, and ethanol exhibit enhanced agar invasion. These carbon sources also promote diploid filamentous growth in response to nitrogen starvation. The enhanced invasive and filamentous growth phenotypes are suppressed by the addition of glucose to the media and require the Snf1 kinase. Mutations in the PGI1 and GND1 genes encoding carbon source utilization enzymes confer enhanced invasive growth that is unaffected by glucose but requires active Snf1. Carbon source does not modulate FLO11 flocculin expression, but enhanced polarized bud site selection is necessary for invasion on certain carbon sources. Interestingly, deletion of SNF1 blocks invasion without affecting bud site selection. Snf1 is also required for formation of spokes and hubs in multicellular mats. To examine glucose repression of invasive growth more broadly, we performed genome-wide microarray expression analysis in wild-type cells growing on glucose and galactose, and snf1 Delta cells on galactose. SNF1 probably mediates glucose repression of multiple genes potentially involved in invasive and filamentous growth. FLO11-independent cell-cell attachment, cell wall integrity, and/or polarized growth are affected by carbon source metabolism. In addition, derepression of cell cycle genes and signalling via the cAMP-PKA pathway appears to depend upon SNF1 activity during growth on galactose.

Ime1 and Ime2 Are Required for Pseudohyphal Growth of Saccharomyces cerevisiae on Nonfermentable Carbon Sources

“…8D). In contrast, acetate does not induce FLO11 in ⌺1278b cells (70). This potential uncoupling of FLO11 expression from the PKA pathway in SK1 cells may allow SK1 cells to attenuate PKA signaling on nonfermentable carbon sources (5,63) in order to activate IME1 and IME2.…”

“…Furthermore, acetate induced the expression of FLO11 in SK1 cells (Fig. 8D) but not in ⌺1278b cells (70), which may contribute to increased pseudohyphal growth and invasiveness of SK1 strains grown on nonfermentable carbon sources (Fig. 1A and B).…”

EAP1 , a Candida albicans Gene Involved in Binding Human Epithelial Cells

“…FLO11 encodes a cell wall protein required for both invasion and pseudohyphae formation by wild-type S. cerevisiae, presumably by enabling cell-cell and cell-substrate adhesion (38,47). Cells of the S. cerevisiae strain ⌺1278b with deletions of FLO11 do not form pseudohyphae as diploids nor invade agar as haploids (38).…”

Cellular Morphogenesis Under Stress Is Influenced by the Sphingolipid Pathway Gene ISC1 and DNA Integrity Checkpoint Genes in Saccharomyces cerevisiae

“…Cells were grown in the presence of either galactose or butanol, both of which induced extensive morphological aberrations in isc1D cells compared to WT cells (Figure 8, A and B). It is known that a small proportion (2-3%) of WT cells display morphological aberrations after treatment with galactose (Palecek et al 2002). In contrast, butanol has been shown to induce morphological aberrations in haploid WT yeast in a strain-specific manner.…”