Survivin initiates procaspase 3/p21 complex formation as a result of interaction with Cdk4 to resist Fas-mediated cell death

Caspase 3 is ran essential death factor for the Fas-mediated cell death, an d its inactivation in cells is initiated by an interaction with p21 on mito chondria or with PAP family member ILP, Survivin is also a member of HAP fa mily and is specifically expressed during embryogenesis and in tumor cells and suppresses cell death signaling, In our current study, we demonstrated that Survivin translocation into the nucleus is dependent on Fas stimulatio n and cell proliferation. Survivin also interacts with the cell cycle regul ator Cdk4, leading to Cdk2/Cyclin E activation and Rb phosphorylation, As a result of Survivin/Cdk4 complex formation, p21 is released from its comple x with Cdk4 and interacts with mitochondrial procaspase 3 to suppress Fas-m ediated cell death, Here, we propose that Survivin supports procaspase 3/p2 1 complex formation as a result of interaction with Cdk4 resulting in suppr ession of cell death signaling.