Formylation is not strictly necessary because nonformylated Met-tRNAf can function as an initiator.

TLS Online TPP Program

#Id: 10545

#Unit 4. Cell Communication and Cell Signaling

Binding of cytochrome c to the Apaf1 triggers formation of an apoptosome containing seven molecules each of Apaf and cytochrome c and having a sevenfold symmetry. 

TLS Online TPP Program

#Id: 10546

#Unit 4. Cell Communication and Cell Signaling

Apoptosome 

a disk-shaped 1.4-MDa heptameric wheel of death

TLS Online TPP Program

#Id: 10547

#Unit 4. Cell Communication and Cell Signaling

Apoptosis of mammalian cells is activated by either: Intrinsic signaling pathways

Extrinsic signaling pathways

TLS Online TPP Program

#Id: 10548

#Unit 4. Cell Communication and Cell Signaling

Intrinsic apoptosis pathway is mediated by an activated initiator caspase (caspase-9)

TLS Online TPP Program

#Id: 10549

#Unit 4. Cell Communication and Cell Signaling

Extrinsic apoptosis pathway, is initiated by ligands of death receptor family TNFα and FasL (trimeric ligand)

TLS Online TPP Program

#Id: 10550

#Unit 4. Cell Communication and Cell Signaling

Extrinsic (death receptor–regulated) apoptosis pathway

binding of TNFα to TNFR1, a DD-containing death

receptor, recruits another two DD-containing

signaling molecules, TRADD and RIPK1