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Physiology and molecular basis of polyphosphate hyper- and hypo-accumulation in saccharomyces cerevisiae

English title Physiology and molecular basis of polyphosphate hyper- and hypo-accumulation in saccharomyces cerevisiae
Applicant Freimoser Florian
Number 112083
Funding scheme Project funding (Div. I-III)
Research institution Departement Umweltsystemwissenschaften ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Biochemistry
Start/End 01.04.2006 - 31.12.2009
Approved amount 182'350.00
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Keywords (6)

physiology; molecular biology; metabolism; inorganic polyphosphate; polyP; cyclin dependent kinase

Lay Summary (English)

Lead
Lay summary
Inorganic polyphosphate (poly P) consists of linear chains of phosphate residues and occurs in all organisms and cells and in many cellular compartments. It is involved in numerous biological phenomena and functions in cellular processes in all organisms. However, even the most fundamental aspects of poly P metabolism are largely unknown. In yeast, large amounts of poly P accumulate in the vacuole during growth. It is neither known how this poly P pool is synthesized nor how it is remobilized from the vacuole to replenish the cytosolic phosphate pool.We have developed a novel method for the extraction and quantification of inorganic poly P from the yeast Saccharomyces cerevisiae. This method has been adapted for high-throughput analyses and was used for a screen of the complete knockout-collection of all non-essential yeast genes. This large scale poly P analysis revealed an unexpected large number of knockouts with strongly altered poly P levels. The discovered genes encode proteins that localize to and function in all major cellular compartments.It is the goal of the proposed research project to characterize poly P synthesis and function in the discovered mutant strains of S. cerevisiae that hyper- or hypoaccumulate this polymer. The starting point will be detailed poly P analyses in selected mutant strains and in strains overexpressing genes involved in poly P accumulation. The poly P hyper-accumulating strains will then be used as tools to identify pathways that are directly involved in poly P synthesis. For this reason, we will quantify poly P in single and double knockouts, in order to discover suppressor mutants that abolish the poly P hyperaccumulation phenotype of the original knockout strain. The second aim of this project is to describe physiological functions of poly P in yeast. For this goal we will mainly compare the wild-type strain (normal poly P), the single knockout strains pho84? (reduced poly P) and pho85? (higher poly P level) and the double knockout strain pho84?pho85 ? (reduced poly P level), because these represent closely related poly P hyper- and hypoaccumulating strains. First, we will perform a broad screen for growth phenotypes by using the Phenotype MicroArrayTM technology to identify characters that mark out poly P hyper- or hypoaccumulating strains unmistakably. In addition to this broad screening for phenotypes, we will perform detailed growth analyses and compare survival during stationary phase and stress resistance, because these are phenomena in which a function of poly P is implicated. By combining molecular and phenotypic characterization of poly P accumulation in S. cerevisiae, as proposed here, we hope to uncover the complex regulation underlying poly P accumulation and thus make a significant contribution to the understanding of nutrient metabolism in eukaryotes in general.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
The SPX domain of the yeast low-affinity phosphate transporter Pho90 regulates transport activity
Huerlimann Hans Caspar, Pinson Benoit, Stadler-Waibel Martha, Zeeman Samuel C., Freimoser Florian M. (2009), The SPX domain of the yeast low-affinity phosphate transporter Pho90 regulates transport activity, in Embo Reports, 10(9), 1003-1008.
Cordycepin-hypersensitive growth links elevated polyphosphate levels to inhibition of poly(A) polymerase in Saccharomyces cerevisiae
Holbein Sandra, Freimoser Florian M., Werner Thomas P., Wengi Agnieszka, Dichtl Bernhard (2008), Cordycepin-hypersensitive growth links elevated polyphosphate levels to inhibition of poly(A) polymerase in Saccharomyces cerevisiae, in Nucleic Acids Research, 36(2), 353-363.
Inorganic polyphosphate occurs in the cell wall of Chlamydomonas reinhardtii and accumulates during cytokinesis
Werner Thomas P., Amrhein Nikolaus, Freimoser Florian M. (2007), Inorganic polyphosphate occurs in the cell wall of Chlamydomonas reinhardtii and accumulates during cytokinesis, in Bmc Plant Biology, 7, 51.
Pho91 is a vacuolar phosphate phosphate and polyphosphate Saccharomyces cerevisiae
Huerlimann Bans Caspar, Stadler-Waibel Martha, Werner Thomas P., Freimoser Florian M. (2007), Pho91 is a vacuolar phosphate phosphate and polyphosphate Saccharomyces cerevisiae, in Molecular Biology of the Cell, 18(11), 4438-4445.
Specific localization of inorganic polyphosphate (poly P) in fungal cell walls by selective extraction and immunohistochemistry
Werner Thomas P., Amrhein Nikolaus, Freimoser Florian M. (2007), Specific localization of inorganic polyphosphate (poly P) in fungal cell walls by selective extraction and immunohistochemistry, in Fungal Genetics and Biology, 44(9), 845-852.
Systematic screening of polyphosphate (poly P) levels in yeast mutant cells reveals strong interdependence with primary metabolism
Freimoser Florian M., Huerlimann Hans Caspar, Jakob Claude A., Werner Thomas P., Amrhein Nikolaus (2006), Systematic screening of polyphosphate (poly P) levels in yeast mutant cells reveals strong interdependence with primary metabolism, in Genome Biology, 7(11), R109.

Collaboration

Group / person Country
Types of collaboration
Prof. Tao Pan, Dept. of Biochemistry and Molecular Biology, University of Chicago, IL United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Bernhard Dichtl, Institute of Molecular Biology, University of Zürich, Zürich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Hans Lambers, School of Plant Biology, The University of Western Australia Australia (Oceania)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Thomas Seebeck, Institute of Cell Biology, University of Bern Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Seminar-Vortrag Individual talk Manipulation of phosphate metabolism in yeast 06.07.2010 München, Germany Freimoser Florian;
Seminar-Vortrag Individual talk Regulation of phosphate and polyphosphate metabolism by low-affinity phosphate transporters in yeast 05.09.2008 Ottawa, Canada Freimoser Florian;
Seminar-Vortrag Individual talk Regulation of phosphate and polyphosphate metabolism by low-affinity phosphate transporters in yeast 29.07.2008 Bern, Switzerland Freimoser Florian;
2008 Yeast Genetics and Molecular Biology Meeting Poster Yeast mutants with altered polyphosphate content respond differently to phosphate availability 22.07.2008 Toronto, Canada Hürlimann Hans Caspar; Freimoser Florian;
2008 Yeast Genetics and Molecular Biology Meeting Poster Yeast low-affinity phosphate transporters are allosterically inhibited and regulate phosphate metabolism 22.07.2008 Toronto, Canada Freimoser Florian; Hürlimann Hans Caspar;
Seminar-Vortrag Individual talk Polyphosphate reveals surprising functions of low-affinity phosphate transporters 19.09.2007 Frankfurt, Germany Freimoser Florian;
3rd Conference on Physiology of Yeasts and Filamentous Fungi, Helsinki, Finland Talk given at a conference Systematic analysis of polyphosphate in yeast reveals novel functions of phosphate transporters in polyphosphate metabolism 13.06.2007 Helsinki, Finland Freimoser Florian;


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