title: Dap1/PGRMC1 binds and regulates cytochrome P450 enzymes.
abstract: Cytochrome P450 enzymes are heme-dependent monoxygenases that play a central role in human physiology. Despite the numerous physiological processes that P450 enzymes impact, the electron donors P450 oxidoreductase and cytochrome b5 are the only proteins known to interact with and modulate the activity of ER microsomal P450s. Here, we report that Dap1/PGRMC1 is required for ER P450 function in yeast and humans. We show that S. pombe Dap1 is a hemoprotein that binds and positively regulates Cyp51A1 and Cyp61A1, two P450s required for sterol biosynthesis. Similarly, loss of human PGRMC1 reduces activity of Cyp51A1, blocking cholesterol synthesis and increasing production of toxic sterol intermediates. PGRMC1 stably binds Cyp51A1 and human P450s from three additional families including Cyp3A4, which metabolizes pharmaceutical compounds. These findings demonstrate that PGRMC1 is required for P450 activity and suggest that interindividual variation in PGRMC1 function may impact multiple biochemical pathways and drug metabolism.
authors.affiliation: Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Adam L
authors.initials: AL
authors.lastname: Hughes
authors.forename: David W
authors.initials: DW
authors.lastname: Powell
authors.forename: Martin
authors.initials: M
authors.lastname: Bard
authors.forename: James
authors.initials: J
authors.lastname: Eckstein
authors.forename: Robert
authors.initials: R
authors.lastname: Barbuch
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Link
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Espenshade
mesh_terms: D002784:Cholesterol / Q000096:biosynthesis; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006418:Heme / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000201:enzymology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D017385:Sequence Homology
chemical_list: D008565:Membrane Proteins; C115296:PGRMC1 protein, human; D011980:Receptors, Progesterone; D029702:Schizosaccharomyces pombe Proteins; D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D002784:Cholesterol