Titre

Coupled synthesis and translocation restrains polyphosphate to acidocalcisome-like vacuoles and prevents its toxicity.

Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Gerasimaitė, R.
Auteure/Auteur
Sharma, S.
Auteure/Auteur
Desfougères, Y.
Auteure/Auteur
Schmidt, A.
Auteure/Auteur
Mayer, A.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
1477-9137
Statut éditorial
Publié
Date de publication
2014
Volume
127
Numéro
23
Première page
5093
Dernière page/numéro d’article
5104
Langue
anglais
Résumé
Eukaryotes contain inorganic polyphosphate (polyP) and acidocalcisomes, which sequester polyP and store amino acids and divalent cations. Why polyP is sequestered in dedicated organelles is not known. We show that polyP produced in the cytosol of yeast becomes toxic. Reconstitution of polyP translocation with purified vacuoles, the acidocalcisomes of yeast, shows that cytosolic polyP cannot be imported, whereas polyP produced by the vacuolar transporter chaperone (VTC) complex, an endogenous vacuolar polyP polymerase, is efficiently imported and does not interfere with growth. PolyP synthesis and import require an electrochemical gradient, probably as a driving force for polyP translocation. VTC exposes its catalytic domain to the cytosol and carries nine vacuolar transmembrane domains. Mutations in the VTC transmembrane regions, which are likely to constitute the translocation channel, block not only polyP translocation but also synthesis. Given that they are far from the cytosolic catalytic domain of VTC, this suggests that the VTC complex obligatorily couples synthesis of polyP to its import in order to avoid toxic intermediates in the cytosol. Sequestration of otherwise toxic polyP might be one reason for the existence of acidocalcisomes in eukaryotes.
Sujets

Yeast vacuole

Inorganic polyphospha...

VTC complex

Acidocalcisome

PID Serval
serval:BIB_97FEDD1E48BE
DOI
PMID
WOS
Permalien
Open Access
Oui
Date de création
2015-01-02T08:32:26.792Z
Date de création dans IRIS
2025-05-20T23:08:21Z
Fichier(s)
En cours de chargement...
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Nom

5093.full.pdf

Version du manuscrit

preprint

Taille

1.64 MB

Format

Adobe PDF

PID Serval

serval:BIB_97FEDD1E48BE.P001

URN

urn:nbn:ch:serval-BIB_97FEDD1E48BE0

Somme de contrôle

(MD5):814bd0538549f66dedc6dafd13fea330