Functions of inorganic polyphosphates in eukaryotic cells: a coat of many colours

PolyP (inorganic polyphosphate) is a linear polymer of tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. This polymer is present in all living organisms from bacteria to mammals. Until recently, most of the studies on polyP have focused on its function in prokaryotes. In prokaryotes, polyP has been implicated in many unrelated processes ranging from basic metabolism to structural functions. However, polyP analysis and function in higher eukaryotes has been gaining momentum recently. In the present review, we mainly aim to discuss the proposed intracellular functions of polyP in higher eukaryotes and its detection methods.