Flippase

Structure of a flippase, showing the two major subunits of the enzyme.

Flippases are transmembrane lipid transporter proteins located in the cell membrane. They are responsible for aiding the movement of phospholipid molecules between the two layers, or leaflets, that compose the membrane (transverse diffusion, also known as a "flip-flop" transition). Flippases move lipids to the cytosolic layer, usually from the extracellular layer. Floppases do the opposite, moving lipids to the extracellular layer. Both flippases and floppases are powered by ATP hydrolysis and are either P4-ATPases or ATP-Binding Cassette transporters. Scramblases are energy-independent and transport lipids in both directions.[1][2][3]

  1. ^ Maxfield, Frederick R.; Menon, Anant K. (2016), "Intramembrane and Intermembrane Lipid Transport", Biochemistry of Lipids, Lipoproteins and Membranes, Elsevier, pp. 415–436, doi:10.1016/b978-0-444-63438-2.00014-6, ISBN 978-0-444-63438-2, retrieved 2024-06-04
  2. ^ Graham, Todd R. (20 July 2021). "Tour de flippase". ASMBM Today. Retrieved 4 June 2024.
  3. ^ Andersen, Jens P.; Vestergaard, Anna L.; Mikkelsen, Stine A.; Mogensen, Louise S.; Chalat, Madhavan; Molday, Robert S. (2016-07-08). "P4-ATPases as Phospholipid Flippases—Structure, Function, and Enigmas". Frontiers in Physiology. 7. doi:10.3389/fphys.2016.00275. ISSN 1664-042X. PMC 4937031. PMID 27458383.