Membrane organization | Lipid Transporters: Flippases, Floppases and Scramblases

Cellular membranes are composed of a bilayer of lipids that present a characteristic asymmetric distribution between the two leaflets. This transbilayer asymmetry is essential to sustain cellular functions, such as cell-to-cell communication or nutrient uptake, and its disruption is an indicator of cell death. Cells employ a broad range of lipid transporters to establish, maintain, and disrupt transbilayer asymmetry. According to their direction of transport and energy requirements, these lipid transporters are classified into flippases, floppases and scramblases. This work summarizes the main features and functions of each protein group.