Phosphoinositides (PIPns) are minor components of cellular membranes but are integral signaling molecules for cellular communication. Phosphatidylinositol 4,5-bisphosphate (PIP2) has been shown to play a central role in a variety of cellular functions. Amongst its many functions, PIP2 is a substrate for Phospholipase C-coupled G-protein pathways involved in intracellular calcium release in a number of tissues. It is also a substrate for class I phosphoinositide 3-kinase (PI3-K) forming PI(3,4,5)P3.
GloPIPs are labeled at the sn-1 position with BODIPY®-FL (505/513), BODIPY®-TMR (544/574), or biotin. The sn-1 linkage in these labeled PIPs has been changed to a more stable amide from an ester. Results from experiments conducted at Echelon indicated that this minor chemical change did not have a significant effect in any of the applications tested.