MLKL

MLKL (mixed lineage kinase domain-like protein) is the terminal executioner of necroptosis and a pseudokinase whose kinase-like domain has lost catalytic function and instead acts as a molecular switch. Upon death-receptor-driven necroptotic signaling, RIPK3 phosphorylates the activation loop of the MLKL pseudokinase domain, releasing an N-terminal four-helix bundle that oligomerizes, translocates to the plasma membrane and permeabilizes it, causing lytic cell death and release of inflammatory mediators. MLKL is expressed in most mammalian tissues, with high levels in hematopoietic cells. Because necroptosis contributes to inflammation, infection and ischemic injury, MLKL is a focal point for therapeutic intervention and antibody research.