The osmotic integrity of the yeast cell requires a functional PKC1 gene product.

Abstract

Seven temperature-sensitive cell lysis (cy) mutant strains of Saccharomyces cerevisiae were isolated which lyse at the restrictive temperature on hypotonic but not on osmotically supported medium. The seven mutants fell into four complementation groups, CLY12 to CLY15. The wild-type CLY1S gene was isolated by complementation of the clyl5 temperature-sensitive growth defect. Sequence analysis revealed that the complementing DNA fragment encoded a partial PKC1 gene, which has previously been isolated as an S. cerevisiae homolog of mammalian protein kinase C genes (D. E. Levin, F. 0. Fields, R. Kunisawa, J. M. Bishop, and J. Thorner, Cell 62:213-224, 1990 The yeast cell wall is a complex rigid structure, responsible for cell shape, which undergoes a series of significant changes during the mitotic cell cycle (6). For example, bud emergence requires modifications of the cell wall at a precisely localized site and controlled cell wall growth in order to produce a daughter cell. Other cellular processes such as mating and sporulation also involve specific alterations of the cell wall structure.Yeast cell walls are constructed almost entirely of two classes of polysaccharides: polymers of mannose covalently linked to peptides, which are termed mannoproteins, and polymers of glucose, termed glucans. A third sugar polymer of N-acetylglucosamine, chitin, is present in only minor amounts (8). A number of Saccharomyces cerevisiae mutants with defects in the synthesis of cell wall components have been isolated. Defects in agglutination with a 1,3-alinked mannose antiserum define mannoprotein (mnn) mutants (reviewed in Ballou [1]), yeast killer toxin-resistant (kre) mutants display reduced levels of 1,6-,-glucan in the cell wall (2), and chitin synthase mutants are unable to convert exogenous glucosamine to chitin (3,22). The major cell wall-degrading enzyme activities mainly consist of 1,3-,-and

Global changes in protein synthesis during adaptation of the yeast Saccharomyces cerevisiae to 0.7 M NaCl

“…In theory, only one signalling path could differentially and sequentially affect the expression of a number of genes; however, it is tempting to envisage a number of parallel signalling paths. This line of thought is partly supported by the reported impact on salt-dependent ENA1 expression by the Ca 2ϩ -dependent protein phosphatase calcineurin (29) and by the importance of protein kinase C, Pkc1p, for the osmotic integrity of the yeast cell (34). These paths in conjunction with the HOG1-mediated signal may trigger most of the observed regulatory effects.…”

Genome‐wide screen of Saccharomyces cerevisiae for killer toxin HM‐1 resistance

“…The OST complex has been suggested to be a direct target of Pkc1 kinase (Chavan et al, 2003a;Kelleher et al, 2003;Park and Lennarz, 2000), which is a homologue of mammalian protein kinase C and controls the CWI pathway at upstream of Slt2p (Lee et al, 1993;Martin et al, 1996;Paravicini et al, 1992;Sussman et al, 2004). In response to cell wall damage caused by HM-1 action, activated-Pkc1 may activate the OST complex to increase highly-glycosylated mannoprotein production in the cell wall.…”

The Hsp110 protein chaperone Sse1 is required for yeast cell wall integrity and morphogenesis

“…The alkaline phosphatase cell leakage assay was performed as described with minor modifications (Paravicini et al 1992). Cells were suspended to a density of approximately 10 6 cells/mL in 180 µL of YPD in a sterile 96-well plate, and a multiprong replicator (Sigma) was used to spot each strain onto YPD plates.…”

“…To ask whether these growth phenotypes correlated with defects in cell integrity, we assessed leakage of endogenous alkaline phosphatase. This assay provides a colorimetric readout of cell lysis using the chromogenic substrate BCIP (Paravicini et al 1992). All the single mutants, as well as the swi4Δ sse1Δ double mutant strain, exhibited little to no alkaline phosphatase activity after 2 days of growth at 37°C.…”

“…Cell wall damage is transmitted by protein kinase C to a MAP kinase module terminating in the MAPK Slt2 (Torres et al 1991;Levin and Bartlett-Heubusch 1992;Paravicini et al 1992). Slt2 (also known as Mpk1) phosphorylates and activates two transcription factors, Rlm1 and the Swi4/6 cell-cycle box binding factor (SBF), the latter a heterodimer composed of Swi4 and Swi6 proteins (Watanabe et al 1995;Dodou and Treisman 1997;Madden et al 1997;Jung et al 2002).…”