Fig. 1.
Extrinsic signal-induced mitochondrial apoptotic pathway. Blue lines indicate binding, red lines indicate activation, and black lines indicate conformational transformation. Bax*, activated Bax; colon, protein complex; MOM superscript, proteins on mitochondrial outer membrane. Different functions of Bcl2 family proteins, such as Activator, Inhibitor, Effector, and Sensitizer, are colored in red, green, yellow, and orange, respectively. Heterodimers are colored in blue. Apoptosis is induced by activated caspase8; Bax oligomers (denoted by BaxMOM4) create pores in the mitochondrial outer membrane, which causes MOMP and cell death initiation. Proteins with redundant function are compressed into a representative reactant; Bax and Bak are represented by Bax, and Bcl2, Bcl-xl, and Mcl-1 are represented by Bcl2.