Fig 2
From: Convergence and Divergence of the Signaling Pathways for Insulin and Phosphoinositolglycans
Hypothetical model for the generation of soluble PIG molecules in insulin-sensitive cells from free GPI lipids.
The GPI lipids are located at the extracellular leaflet of the plasma membrane by single lipolytic cleavage through a phospholipase (PL; left) or from GPI-anchored plasma membrane proteins by the combined actions of a phospholipase and protease (right). The PIG molecules are then transported across the plasma membrane through a channel or translo-case (box). Possible modes for the regulation of the phospholipase and protease by the insulin receptor (IR) through phosphorylation and G proteins are indicated.