RNA Polymerase SDS page shows two very large subunits: beta (b) and beta-prime (b’), with molecular masses of 150 and 160 kD, respectively.

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

TLS Online TPP Program

#Id: 10551

#Unit 4. Cell Communication and Cell Signaling

The activation of RIPK1 kinase is a key decisive event that can initiate cell death by either apoptosis or necroptosis.

TLS Online TPP Program

#Id: 10552

#Unit 4. Cell Communication and Cell Signaling

Activated RIPK1 can bind to FADD, which serves as an adapter to recruit and activate caspase-8

TLS Online TPP Program

#Id: 10553

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 10554

#Unit 4. Cell Communication and Cell Signaling

FADD can also be directly activated by binding to TRADD in RIPK1-independent apoptosis activation.