NLSs were first discovered through the analysis of mutations of the gene for large T-antigen encoded by simian virus 40 (SV40).

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

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#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.

TLS Online TPP Program

#Id: 10555

#Unit 4. Cell Communication and Cell Signaling

Caspase-8 cleaves and activates several effector caspases, caspase-3, 6, 7 to complete apoptotic cell death.