Posttranslational N-myristoylation of BID as a molecular switch for targeting mitochondria and apoptosis

Many apoptotic molecules relocate subcellularly in cells undergoing apoptos is. The pro-apoptotic protein BID underwent posttranslational (rather than classic cotranslational) N-myristoylation when cleavage by caspase 8 caused exposure of a glycine residue. N-myristoylation enabled the targeting of a complex of p7 and myristoylated p15 fragments of BID to artificial membran es bearing the Lipid composition of mitochondria, as well as to intact mito chondria. This post-proteolytic N-myristoylation serves as an activating sw itch, enhancing BID-induced release of cytochrome c and cell death.