Phosphatidylinositol

Phosphatidylinositol consists of a very large family of complex compounds as illustrated on the right. They are negatively charged due to the phospholipid and a minor component in the cytosolic side of eukaryotic cell membranes. The specific lipid chains are typically not identified and the specific isomer of the nine possible isomers of inositol is not specified.

The specific phosphatidylinositol using the isomer, muco-inositol is used as a sensory receptor in the gustatory modality of the sensory system. It is typically identified as PtdIns in the sensory literature.

The other forms of phosphatidylinositol are commonly addressed as PI in the more general biochemical literature.

The phosphatidylinositol can be phosphorylated to form phosphatidylinositol phosphate (PIP), phosphatidylinositol bisphosphate (PIP₂) and phosphatidylinositol trisphosphate (PIP₃). PIP, PIP₂ and PIP₃ are collectively called phosphoinositides.