Incorporation of a fluorous diazirine group into phosphatidylinositol 4,5-bisphosphate to illustrate its interaction with ADP-ribosylation factor 1

Phosphatidylinositides are one family of the most versatile signaling molecules in cells, yet how they interact with different proteins to regulate biological processes is not well understood. Towards a general strategy to identify phosphatidylinositide–protein interactions, a fluorous diazirine group has been incorporated into phosphatidylinositol 4,5-bisphosphate (PIP2). The modified PIP2 was effectively cleaved by phospholipase C, one signaling protein that utilizes PIP2 as its endogenous substrate. Upon light illumination, the PIP2 probe effectively crosslinks with small GTPase ADP-ribosylation 1 to form a complex, suggesting that the probe might be suitable to identify PIP2-interacting proteins on the proteome level.