Figure 4.

Role of heat shock protein 27 (HSP27) in different cellular apoptotic processes. HSP27 inhibits apoptosis by integrating with different signaling pathways, including the extrinsic and intrinsic apoptosis pathway. HSP27 inhibits Bcl-2-associated X protein (BAX) by directly binding to death domain associated protein (DAXX) or apoptosis signal-regulating kinase-1 (Ask-1) to inhibit its function, which enhances AKT activity inhibiting BH3 interacting-domain death agonist (BID) or protein kinase C delta type (PKC δ) function. HSP27 inhibits caspase 3, which directly functions in cellular apoptosis. HSP27 contributes to cell survival.