Acidocalcisome-like vacuoles constitute a feedback-controlled phosphate buffering system for the cytosol.

ABSTRACT: Cells experience strong variations in the consumption and availability of inorganic phosphate (P_i). Since P_i is an essential macronutrient but excess P_i has negative impacts on nucleotide hydrolysis and metabolism, its concentration must be maintained in a suitable range. Conserved storage organelles, acidocalcisomes, provide this buffering function. We used acidocalcisome-like yeast vacuoles to study how such organelles are set up to perform this task. Our combined in vitro and in vivo analyses revealed that their ATP-driven polyphosphate polymerase VTC converts cytosolic P_i into inorganic polyphosphates (polyP), which it transfers into the vacuole lumen. Luminal polyphosphatases immediately hydrolyse this polyP to establish a growing reservoir

SUBMITTER: Bru S 

PROVIDER: S-EPMC12668673 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature