title: Deregulation of DSE1 gene expression results in aberrant budding within the birth scar and cell wall integrity pathway activation in Saccharomyces cerevisiae.
abstract: Strains of Saccharomyces cerevisiae lacking Isw2, the catalytic subunit of the Isw2 chromatin remodeling complex, show the mating type-independent activation of the cell wall integrity (CWI) signaling pathway. Since the CWI pathway activation usually reflects cell wall defects, we searched for the cell wall-related genes changed in expression. The genes DSE1, CTS1, and CHS1 were upregulated as a result of the absence of Isw2, according to previously published gene expression profiles (I. Frydlova, M. Basler, P. Vasicova, I. Malcova, and J. Hasek, Curr. Genet. 52:87-95, 2007). Western blot analyses of double deletion mutants, however, did not indicate the contribution of the chitin metabolism-related genes CTS1 and CHS1 to the CWI pathway activation. Nevertheless, the deletion of the DSE1 gene encoding a daughter cell-specific protein with unknown function suppressed CWI pathway activation in isw2Delta cells. In addition, the deletion of DSE1 also abolished the budding-within-the-birth-scar phenotype of isw2Delta cells. The plasmid-driven overexpression proved that the deregulation of Dse1 synthesis was also responsible for CWI pathway activation and manifestation of the budding-within-the-birth-scar phenotype in wild-type cells. The overproduced Dse1-green fluorescent protein localized to both sides of the septum and persisted in unbudded cells. Although the exact cellular role of this daughter cell-specific protein has to be elucidated, our data point to the involvement of Dse1 in bud site selection in haploid cells.
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Frydlová
authors.forename: Ivana
authors.initials: I
authors.lastname: Malcová
authors.forename: Pavla
authors.initials: P
authors.lastname: Vasicová
authors.forename: Jirí
authors.initials: J
authors.lastname: Hasek
mesh_terms: D002455:Cell Division; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity