Signal transduction in astrocytes: Localization and release of inorganic polyphosphate.

Inorganic polyphosphate (polyP) is present in every cell and is highly conserved from primeval times. In the mammalian cells, polyP plays multiple roles including control of cell bioenergetics and signal transduction. In the brain, polyP mediates signaling between astrocytes via activation of purinergic receptors, however, the mechanisms of polyP release remain unknown.