Vtc5, a Novel Subunit of the Vacuolar Transporter Chaperone Complex, Regulates Polyphosphate Synthesis and Phosphate Homeostasis in Yeast.

Details

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State: Public
Version: Final published version
Serval ID
serval:BIB_7BF982ABD76F
Type
Article: article from journal or magazin.
Collection
Publications
Title
Vtc5, a Novel Subunit of the Vacuolar Transporter Chaperone Complex, Regulates Polyphosphate Synthesis and Phosphate Homeostasis in Yeast.
Journal
The Journal of biological chemistry
Author(s)
Desfougères Y., Gerasimaitė R.U., Jessen H.J., Mayer A.
ISSN
1083-351X (Electronic)
ISSN-L
0021-9258
Publication state
Published
Issued date
14/10/2016
Peer-reviewed
Oui
Volume
291
Number
42
Pages
22262-22275
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
SPX domains control phosphate homeostasis in eukaryotes. Ten genes in yeast encode SPX-containing proteins, among which YDR089W is the only one of unknown function. Here, we show that YDR089W encodes a novel subunit of the vacuole transporter chaperone (VTC) complex that produces inorganic polyphosphate (polyP). The polyP synthesis transfers inorganic phosphate (Pi) from the cytosol into the acidocalcisome- and lysosome-related vacuoles of yeast, where it can be released again. It was therefore proposed for buffer changes in cytosolic Pi concentration (Thomas, M. R., and O'Shea, E. K. (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 9565-9570). Vtc5 physically interacts with the VTC complex and accelerates the accumulation of polyP synthesized by it. Deletion of VTC5 reduces polyP accumulation in vivo and in vitro Its overexpression hyperactivates polyP production and triggers the phosphate starvation response via the PHO pathway. Because this Vtc5-induced starvation response can be reverted by shutting down polyP synthesis genetically or pharmacologically, we propose that polyP synthesis rather than Vtc5 itself is a regulator of the PHO pathway. Our observations suggest that polyP synthesis not only serves to establish a buffer for transient drops in cytosolic Pi levels but that it can actively decrease or increase the steady state of cytosolic Pi.

Keywords
Carrier Proteins/genetics, Carrier Proteins/metabolism, Molecular Chaperones/genetics, Molecular Chaperones/metabolism, Polyphosphates/metabolism, Saccharomyces cerevisiae/genetics, Saccharomyces cerevisiae/metabolism, Saccharomyces cerevisiae Proteins/genetics, Saccharomyces cerevisiae Proteins/metabolism
Pubmed
Open Access
Yes
Create date
21/09/2016 18:17
Last modification date
20/08/2019 15:37
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