Inorganic polyphosphate is required for sustained free mitochondrial calcium elevation, following calcium uptake.

ABSTRACT: Mitochondrial free calcium is critically linked to the regulation of cellular metabolism. Free ionic calcium concentration within these organelles is determined by the interplay between two processes: exchange across the mitochondrial inner membrane and calcium-buffering within the matrix. During stimulated calcium uptake, calcium is primarily buffered by orthophosphate, preventing calcium toxicity while allowing for well-regulated yet elevated calcium loads. However, if limited to orthophosphates only, this buffering system is expected to lead to the irreversible formation of insoluble precipitates, which are not observed in living cells, under physiological conditions. Here, we demonstrate that the regulation of free mitochondrial calcium requires the presence of free inorganic polyphosp

SUBMITTER: Solesio ME 

PROVIDER: S-EPMC7024051 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature