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Assaying for Inorganic Polyphosphate in Bacteria
Published on: January 21, 2019
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The PPIP5K Family Member Asp1 Controls Inorganic Polyphosphate Metabolism in S. pombe
Marina Pascual-Ortiz1,2, Eva Walla1, Ursula Fleig1
1Eukaryotische Mikrobiologie, Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich Heine University, 40225 Düsseldorf, Germany.
Journal of Fungi (Basel, Switzerland)
|August 26, 2021
Summary
Inorganic polyphosphate (polyP) regulation is conserved in yeasts, but the specific inositol pyrophosphate (IPP) molecule controlling it differs. Fission yeast uses IP8, unlike budding yeast
Area of Science:
- Molecular Biology
- Yeast Genetics
- Biochemistry
Background:
- Inorganic polyphosphate (polyP) is a versatile polymer found in all cells, playing roles in cell cycle, phosphate balance, and protein modification.
- In budding yeast (Saccharomyces cerevisiae), polyP synthesis is regulated by inositol pyrophosphates (IPPs) like IP7, produced by Kcs1, which interact with the VTC complex.
- Understanding polyP regulation is crucial due to its diverse biological functions.
Purpose of the Study:
- To investigate the evolutionary conservation of polyP regulation mechanisms in distantly related yeasts.
- To identify the specific IPP regulators of polyP generation in fission yeast (Schizosaccharomyces pombe).
- To compare the IPP-mediated regulation of polyP synthesis between S. cerevisiae and S. pombe.
Main Methods:
- Comparative analysis of polyP metabolism in S. pombe and S. cerevisiae.
- Genetic manipulation of Asp1, a key enzyme in S. pombe, and its variants.
- Quantification of cellular polyP levels and IPP species (specifically IP8).
- Biochemical assays to study the interaction between IPPs and the VTC complex.
Main Results:
- The VTC machinery is essential for polyP generation in S. pombe, similar to S. cerevisiae.
- In contrast to S. cerevisiae, polyP metabolism in S. pombe is regulated by IP8, produced by Asp1.
- Cellular polyP levels in S. pombe directly correlate with Asp1-made IP8 levels, indicating dose-dependent regulation.
Conclusions:
- The fundamental mechanism of polyP synthesis is conserved across yeast species.
- The specific IPP molecule acting as a regulator of polyP metabolism varies between yeast species (e.g., IP7 in S. cerevisiae vs. IP8 in S. pombe).
- This highlights the diversity in regulatory components despite conserved core pathways in eukaryotic cells.
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