LC-MSMS with isobaric tagging of Pgrmc1 KO mouse liver membranes expressing Flag-Pgrmc1 or Y113F Flag-Pgrmc1

Progesterone receptor membrane component 1 (PGRMC1) is a heme binding protein implicated in a wide range of cellular functions. Our previous studies showed that PGRMC1 binds to cytochromes P450 in yeast and mammalian cells and promotes activity of these enzymes. Recently, the paralog PGRMC2 was shown to function as an intracellular heme chaperone. Here, we examined the function of the Pgrmc1 Y113F mutant that is defective for heme iron coordination by measuring levels of membrane proteins in livers from Pgrmc1 knockout mice infected with AAV8 expressing either GFP, Flag-Pgrmc1, or Y113F Flag-Pgrmc1. These experiments (1) confirmed findings in uninfected wild-type and Pgrmc1 knockout mice and (2) revealed that Pgrmc1 Y113F functions to stabilize cytochrome P450 enzymes similar to wild-type Pgrmc1.