fig2

Figure 2. Myeloid cell leukaemia-1 (Mcl-1) regulates initiation of apoptosis through interaction with other Bcl-1 family members. Under normal circumstances, Mcl-1 prevents the activation of Bax and Bak to protect mitochondrial outer membrane integrity and cell survival. Under conditions of stress, the BH3 only proteins are activated and induce apoptosis either by releasing Bak/Bax from Mcl-1 or by BH3 only proteins binding to Mcl-1 directly. Bak/Bax form pores on mitochondrial outer membrane and cytochrome C is relieved into the cytoplasm. In the cytoplasm, cytochrome C activates a family of cysteine proteases named caspases which subsequently induce cell apoptosis