The inositol headgroup: The name-giving structure of phosphoinositides is the inositol ring in the polar headgroup of phosphatidylinositol (PtdIns) which can be phosphorylated by specific lipid kinases to produce polyphosphoinositides, such as phosphatidylinositol 4-phosphate (PtdIns4P) or phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P₂). The orchestration of the variety of cellular functions is achieved by the phosphorylation of the inositol headgroup by stereospecific phosphoinositide kinases.

*Click here to view structures of phosphoinositides found in plants.

Cellular functions of Phosphoinositides

The inositol headgroup

Cellular localization of phosphoinositides

Phosphoinositides as central mediators of plant growth responses

Unique properties of plant phosphoinositide metabolism

Inositol 1,4,5-trisphosphate regulates intracellular Ca²⁺ levels