Osmotic shock affects cell wall and cytoskeleton in Saccharomyces cerevisiae
| Authors | |
|---|---|
| Year of publication | 2000 |
| Type | Article in Periodical |
| Magazine / Source | Cellular and Molecular Biology |
| MU Faculty or unit | |
| Citation | |
| Field | Microbiology, virology |
| Keywords | cytoskeleton; cell wall; osmotic shock; yeasts |
| Description | Hyperosmotic growth medium containing 1 M KCl, 1 M mannitol, and/or 1 M glycerol caused cessation of yeast growth for about 2 h and thereafter the growth resumed at almost the original rate. Fluorescent patches on the inner surface of cell walls stained with Calcofluor white was observed. The patches gradually disappeared in buds formed in hyperosmotic medium. Freeze-etched replicas of osmotically stressed cells revealed deep plasma membrane invaginations filled from the periplasmic side with amorphous cell-wall material. The rate of incorporation of D-[U-14C]glucose into the individual cell wall polysaccharides during osmotic shock followed the growth kinetics. No differences in the composition of the cell walls from osmotically stressed yeast and those from the control cells was found. Microtubules disappeared and actin patches were present in both mother cell and bud. After 2 - 3 h in hyperosmotic medium, both microtubules and microfilaments regenerated to their original polarized forms. Strains of S. cerevisiae with mutations in the osmosensing HOG pathway hog1 and pbs2 gave similar response to hyperosmotic shock as the wild-type strain. We conclude that, the hyperosmotic shock causes changes in microtubules, actin cytoskeleton and in the organization of the cell wall. These changes are not dependent on HOG pathway. |
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