title: Lipid somersaults: Uncovering the mechanisms of protein-mediated lipid flipping.
abstract: Membrane lipids diffuse rapidly in the plane of the membrane but their ability to flip spontaneously across a membrane bilayer is hampered by a significant energy barrier. Thus spontaneous flip-flop of polar lipids across membranes is very slow, even though it must occur rapidly to support diverse aspects of cellular life. Here we discuss the mechanisms by which rapid flip-flop occurs, and what role lipid flipping plays in membrane homeostasis and cell growth. We focus on conceptual aspects, highlighting mechanistic insights from biochemical and in silico experiments, and the recent, ground-breaking identification of a number of lipid scramblases.
authors.affiliation: Faculty of Chemistry and Biochemistry, Molecular Biochemistry, Ruhr University Bochum, Universitätstrasse 150, D-44780 Bochum, Germany; Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark. Electronic address: tgp@plen.ku.dk.
authors.forename: Thomas Günther
authors.initials: TG
authors.lastname: Pomorski
authors.affiliation: Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA. Electronic address: akm2003@med.cornell.edu.
authors.forename: Anant K
authors.initials: AK
authors.lastname: Menon
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D012243:Rhodopsin / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D008563:Membrane Lipids; D008565:Membrane Proteins; D010743:Phospholipids; D012243:Rhodopsin
keywords: Flippase; Floppase; Membrane asymmetry; Phosphatidylserine; Photoreceptor; Scramblase