title: Characterization of alcohol-induced filamentous growth in Saccharomyces cerevisiae.
abstract: Diploid cells of the budding yeast Saccharomyces cerevisiae starved for nitrogen differentiate into a filamentous growth form. Poor carbon sources such as starches can also stimulate filamentation, whereas haploid cells undergo a similar invasive growth response in rich medium. Previous work has demonstrated a role for various alcohols, by-products of amino acid metabolism, in altering cellular morphology. We found that several alcohols, notably isoamyl alcohol and 1-butanol, stimulate filamentous growth in haploid cells in which this differentiation is normally repressed. Butanol also induces cell elongation and changes in budding pattern, leading to a pseudohyphal morphology, even in liquid medium. The filamentous colony morphology and cell elongation require elements of the pheromone-responsive MAPK cascade and TEC1, whereas components of the nutrient-sensing machinery, such as MEP2, GPA2, and GPR1, do not affect this phenomenon. A screen for 1-butanol-insensitive mutants identified additional proteins that regulate polarized growth (BUD8, BEM1, BEM4, and FIG1), mitochondrial function (MSM1, MRP21, and HMI1), and a transcriptional regulator (CHD1). Furthermore, we have also found that ethanol stimulates hyperfilamentation in diploid cells, again in a MAPK-dependent manner. Together, these results suggest that yeast may sense a combination of nutrient limitation and metabolic by-products to regulate differentiation.
authors.affiliation: Department of Genetics, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Lorenz
authors.forename: N S
authors.initials: NS
authors.lastname: Cutler
authors.forename: J
authors.initials: J
authors.lastname: Heitman
mesh_terms: D000438:Alcohols / Q000494:pharmacology*; D000440:Butanols / Q000494:pharmacology; D003470:Culture Media; D006238:Haploidy; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development
chemical_list: D000438:Alcohols; D000440:Butanols; D003470:Culture Media