In one report, the ER resident phosphatase Sac1 was found to dephosphorylate PIPs localized in the PM in yeast.
A second study suggested that Opi3, an enzyme in the ER that forms phosphatidylcholine (PC) from PE, can use PE in the
plasma membrane as a substrate.
Remarkably, lipidbinding proteins localized at ER–plasma membrane MCSs
regulate the activity of Sac1 and Opi3.
Thus lipid sensing at MCSs may regulate plasma membrane lipid composition.