Phospholipid flippases: Building asymmetric membranes and transport vesicles

► Evidence that type IV P-type ATPases (P4-ATPases) are phospholipid flippases. ► Phospholipid flippases create membrane phospholipid asymmetry. ► Phospholipid flippases play critical roles in vesicular transport. ► P4-ATPases are linked to many disease states. ► Mechanisms for regulating flippase activity are being uncovered.