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Regulated vacuole fusion and fission in Schizosaccharomyces pombe: an osmotic response dependent on MAP kinases.
Curr Biol. 1998 Jan 29; 8(3):135-44.CB

Abstract

BACKGROUND

The budding yeast Saccharomyces cerevisiae uses two mitogenactivated protein (MAP) kinase cascades, the Hog1p and the Mpk1p pathways, to signal responses to hypertonic and hypotonic stress, respectively. Mammalian cells and the fission yeast Schizosaccharomyces pombe have functional homologues of Hog1p - p38/RK/CSBP and Sty1 - which, unlike Hog1p, also mediate other responses. We have investigated the involvement of S. pombe MAP kinase pathways in signalling a newly described response to osmotic stress - that of vacuole fusion and fission.

RESULTS

When S. pombe is placed into water, its vacuoles rapidly fuse into larger structures enclosing a greater proportion of the cell's volume. Under some conditions, its vacuoles can slowly fragment in response to salt. Fission requires the Sty1 pathway and also Pmk1, the homologue of S. cerevisiae Mpk1p. Fusion requires Pmk1, Ypt7 - the homologue of a protein involved in S. cerevisiae vacuole fusion - and part of the Sty1 pathway, although Sty1 phosphorylation is unaffected by hypotonic conditions.

CONCLUSIONS

Vacuole fusion and fission appear to be homeostatic mechanisms that restore the concentration of the cytosol. Vacuole fusion, like stimulated secretion in higher eukaryotes, is a rapid and specific process of membrane fusion in response to an external stimulus. The Sty1 pathway, in addition to its role in responding to hypertonic stress, is required at a basal level for the expression of factors required to respond to hypotonic stress - a mechanism that may allow the cell to use a common pathway for different responses.

Authors+Show Affiliations

School of Biological Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9443913

Citation

Bone, N, et al. "Regulated Vacuole Fusion and Fission in Schizosaccharomyces Pombe: an Osmotic Response Dependent On MAP Kinases." Current Biology : CB, vol. 8, no. 3, 1998, pp. 135-44.
Bone N, Millar JB, Toda T, et al. Regulated vacuole fusion and fission in Schizosaccharomyces pombe: an osmotic response dependent on MAP kinases. Curr Biol. 1998;8(3):135-44.
Bone, N., Millar, J. B., Toda, T., & Armstrong, J. (1998). Regulated vacuole fusion and fission in Schizosaccharomyces pombe: an osmotic response dependent on MAP kinases. Current Biology : CB, 8(3), 135-44.
Bone N, et al. Regulated Vacuole Fusion and Fission in Schizosaccharomyces Pombe: an Osmotic Response Dependent On MAP Kinases. Curr Biol. 1998 Jan 29;8(3):135-44. PubMed PMID: 9443913.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Regulated vacuole fusion and fission in Schizosaccharomyces pombe: an osmotic response dependent on MAP kinases. AU - Bone,N, AU - Millar,J B, AU - Toda,T, AU - Armstrong,J, PY - 1998/4/16/pubmed PY - 1998/4/16/medline PY - 1998/4/16/entrez SP - 135 EP - 44 JF - Current biology : CB JO - Curr Biol VL - 8 IS - 3 N2 - BACKGROUND: The budding yeast Saccharomyces cerevisiae uses two mitogenactivated protein (MAP) kinase cascades, the Hog1p and the Mpk1p pathways, to signal responses to hypertonic and hypotonic stress, respectively. Mammalian cells and the fission yeast Schizosaccharomyces pombe have functional homologues of Hog1p - p38/RK/CSBP and Sty1 - which, unlike Hog1p, also mediate other responses. We have investigated the involvement of S. pombe MAP kinase pathways in signalling a newly described response to osmotic stress - that of vacuole fusion and fission. RESULTS: When S. pombe is placed into water, its vacuoles rapidly fuse into larger structures enclosing a greater proportion of the cell's volume. Under some conditions, its vacuoles can slowly fragment in response to salt. Fission requires the Sty1 pathway and also Pmk1, the homologue of S. cerevisiae Mpk1p. Fusion requires Pmk1, Ypt7 - the homologue of a protein involved in S. cerevisiae vacuole fusion - and part of the Sty1 pathway, although Sty1 phosphorylation is unaffected by hypotonic conditions. CONCLUSIONS: Vacuole fusion and fission appear to be homeostatic mechanisms that restore the concentration of the cytosol. Vacuole fusion, like stimulated secretion in higher eukaryotes, is a rapid and specific process of membrane fusion in response to an external stimulus. The Sty1 pathway, in addition to its role in responding to hypertonic stress, is required at a basal level for the expression of factors required to respond to hypotonic stress - a mechanism that may allow the cell to use a common pathway for different responses. SN - 0960-9822 UR - https://www.unboundmedicine.com/medline/citation/9443913/Regulated_vacuole_fusion_and_fission_in_Schizosaccharomyces_pombe:_an_osmotic_response_dependent_on_MAP_kinases_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0960-9822(98)00060-8 DB - PRIME DP - Unbound Medicine ER -