Publication details
Reakce cytoskeletu a buněčné stěny kvasinek na osmotický šok
| Title in English | Cytoskeleton and cell wall reaction under osmotic stress |
|---|---|
| Authors | |
| Year of publication | 2000 |
| Type | Article in Proceedings |
| Conference | Sborník VIII. Cytoskeletálního klubu |
| MU Faculty or unit | |
| Citation | |
| Field | Microbiology, virology |
| Description | Transfer of logarithmically growing cells of the yeast Saccharomyces cerevisiae to hyperosmotic growth medium containing 0.7-1 M KCl, 1 M mannitol, and/or 1 M glycerol caused arrestment of yeast growth for about 120 min and thereafter the growth resumed at almost the original rate. During this time, formation of fluorescent patches on the inner surface of cell walls stained with Primulin or Calcofluor white was observed. The fluorescent patches were formed also in water solutions of KCl or in conditions when the synthesis of the cell wall was blocked with cycloheximide and/or 2-deoxyglucose. The fluorescent patches on the cell surface gradually disappeared when the cells resumed growth and the new buds had smooth cell walls. Electron microscopy of freeze-etched replicas of osmotically stressed cells revealed deep plasma membrane invaginations filled from the periplasmic side with amorphous cell-wall material which appeared to be counterparts to fluorescent patches on the cell surface. The rate of incorporation of D-[U-14C]glucose from the growth medium 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. Cytoskeletal elements responded to the hyperosmotic shock by disappearance of microtubules and actin microfilaments. After 2 - 3 h in hyperosmotic medium, both microtubules and microfilaments regenerated to their original polarised forms and the actin patches resumed their positions at the apices of growing buds. Strains of Saccharomyces cerevisiae with mutations in the osmosensing pathway hog1 and pbs2 gave similar response to hyperosmotic shock as the wild strain. It is concluded that the hyperosmotic shock causes a change in the organisation of cell wall components, possibly by displacement of a portion of periplasmic and cell wall matrix material into the invaginations of plasma membrane created by the plasmolysis. |
| Related projects: |