MCL1 (MCL-1)

MCL-1 is an anti-apoptotic BCL-2 family member distinguished by its short protein half-life, which makes it the family’s rapid-response survival factor.

Function

MCL-1 binds and neutralizes the pore-formers BAX and BAK, with a binding pattern that overlaps BCL-2 and BCL-xL but matches neither exactly - many cell types depend on MCL-1 specifically, and the BH3-only proteins MCL-1 sequesters differ from those held by its relatives. Because the protein turns over within hours, MCL-1 levels track the cell’s current growth-factor supply: withdrawal of survival signals drops MCL-1 quickly, and the cell becomes primed for death. This lability is why MCL-1 is the anti-apoptotic protein most often recruited by tumors