Topic: Phosphatidylserine

The plasma membrane is characterized by an asymmetric distribution of phospholipids, maintained by three enzyme classes: flippases, floppases, and scramblases. Phosphatidylserine (PS) is confined to the inner leaflet of the plasma membrane under normal conditions, and its externalization has been linked to both apoptotic and non-apoptotic processes within the central nervous system (CNS). Further, neuronal PS exposure can be transient in stressed but viable cells. Thus, interference with PS-triggered phagocytosis of neurons has been suggested to be beneficial in CNS disorders. The mechanism of

Phospholipids are asymmetrically distributed across the plasma membrane. Phosphatidylserine (PS) is concentrated on the cytoplasmic leaflet of the lipid bilayer, but it is externalized in various situations. In the central nervous system, microglia and astrocytes recognize externalized PS on the neuronal plasma membrane. To maintain the PS asymmetry, flippases translocate PS from the exoplasmic leaflet to the cytoplasmic leaflet. Among all flippases, ATP8A1 and ATP8A2 are most abundantly expressed in the neurons in the brain. Genetic defects of ATP8A2 gene in humans cause severe disequilibrium