Cell Death Flashcards
apoptosis
falling off
Difference between apoptosis and necrosis
necrosis: bursting causes an inflammatory response
caspases
cysteine containing proteases that cleave sequences on proteins during apoptosis.
How do initiator caspases work?
inacitve soluble monomers group together, pair up into a dimer to stabilize and activate each other.
How do executioner caspases work?
After paired and activated, catalyze the protein cleavage events.
death receptors
extrinsic pathway triggers: homotrimers of the TNF superfamily.
DISC
Death inducing signal complex: Fas ligand on a killer activates Fas on cell surface, cytolic tails of Fas bind to adaptor proteins which bind to the initiator caspases.
cytochrome c
intrinsic pathway trigger: binds to Apaf1 which become apoptomose which activates the proteins that initiate downstream initiator caspases.
Bcl2 family
suppress/regulates apoptosis
Bax/ Bak
main effector proteins in the Bcl2 family, one is required for the intrinsic pathway to operate.
Bcl2/ BclXl
anti-apoptotoc Bcl family proteins
p53
a tumor suppression protein that accumulates and activates the intrinsic pathway
Bid
the protein that links the two apoptotic pathways.
IAPs
Inhibitors of apoptosis - ensure the proteases only activate when appropriate.
survival factors
cells require continuous signalling from other cells or they die
