Inositol Pyrophosphate Specificity of the SPX-Dependent Polyphosphate Polymerase VTC.

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State: Public
Version: Author's accepted manuscript
License: Not specified
Serval ID
serval:BIB_94917AC5E62D
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Inositol Pyrophosphate Specificity of the SPX-Dependent Polyphosphate Polymerase VTC.
Journal
ACS chemical biology
Author(s)
Gerasimaite R., Pavlovic I., Capolicchio S., Hofer A., Schmidt A., Jessen H.J., Mayer A.
ISSN
1554-8937 (Electronic)
ISSN-L
1554-8929
Publication state
Published
Issued date
17/03/2017
Peer-reviewed
Oui
Volume
12
Number
3
Pages
648-653
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
The free energy of nucleotide hydrolysis depends on phosphate concentration. Cells regulate cytosolic phosphate levels by orchestrating phosphate acquisition and storage through inositol pyrophosphates (PP-InsP) and SPX domains. Here, we report the synthesis of the novel 5-PPP-InsP5 containing a triphosphate subunit. Using this and a series of synthetic PP-InsP, we examined the ligand specificity of the SPX domain in the PP-InsP-controlled yeast polyphosphate polymerase VTC. SPX decodes the relative positioning of the phosphoric anhydrides, their structure (diphosphate vs triphosphate), and the presence of other phosphates on the inositol ring. Despite the higher potency of 1,5-(PP)2-InsP4, 5-PP-InsP5 is the primary activator of VTC in cells, indicating that its higher concentration compensates for its lower potency. 1,5-(PP)2-InsP4 levels rise and could become relevant under stress conditions. Thus, SPX domains may integrate PP-InsP dependent signaling to adapt cytosolic phosphate concentrations to different metabolic situations.
Keywords
Enzymes/metabolism, Inositol Phosphates/metabolism, Polyphosphates/metabolism, Saccharomyces cerevisiae/enzymology, Saccharomyces cerevisiae/metabolism, Substrate Specificity
Pubmed
Web of science
Create date
21/02/2017 19:58
Last modification date
29/07/2020 6:22
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