XK-related protein 8 (XKR8)

XK-related protein 8 (XKR8) is a multi-pass transmembrane protein acting as a **phospholipid scramblase** that is essential for the externalization of phosphatidylserine on the cell surface during apoptosis; this "eat me" signal facilitates recognition and engulfment of dying cells by phagocytes[5][7]. XKR8 forms a complex with basigin (BSG) or neuroplastin to localize correctly at the plasma membrane[1][3][5]. It contains 10 transmembrane domains and is activated upon caspase cleavage or possible phosphorylation in response to apoptotic signals, leading to phospholipid scrambling between the plasma membrane leaflets[1][5]. XKR8 is ubiquitously expressed and is required in processes such as germ cell clearance, immune cell homeostasis, and may be implicated in viral infection through facilitating phosphatidylserine exposure on viral particles[7]. Dysfunction in XKR8 or related apoptotic cell clearance can contribute to autoimmune disease, persistent inflammation, and may be exploitable therapeutically[7][5].

Other names

XK-related protein 8, processed formXKR8XRG8hXkr8FLJ10307XK Kell blood group precursor-related family, member 8X-linked Kx blood group related 8XKKell blood group complex subunit-related family, member 8

Drugs or molecules targeting XKR8 would modulate apoptotic phospholipid scrambling, possibly by inhibiting or activating its activity to affect cell clearance. Caspase activation cleaves XKR8, triggering scramblase activity; phosphorylation may also regulate its function[5][1][3].