Kapitel 18

Question 1

Proteins (e.g. - Bcl2 - BclXL) on the cytosolic surface of the outer mitochondrial membrane that bind and inhibit pro-apoptotic Bcl2 family proteins and thereby help prevent inappropriate activation of the intrinsic pathway of apoptosis.

Answer 1

anti-apoptotic Bcl2 family proteins

Question 2

Produced in response to various apoptotic stimuli and - by binding to IAPs and preventing their binding to a caspase - neutralize the inhibition of apoptosis provided by IAPs.

Answer 2

anti-IAP

Question 3

Adaptor protein of the intrinsic apoptotic pathway; on binding cytochrome c - oligomerizes to form an apoptosome.

Answer 3

Apaf1

Question 4

Form of programmed cell death - in which a “suicide” program is activated within an animal cell - leading to rapid cell death mediated by intracellular proteolytic enzymes called caspases.

Answer 4

apoptosis

Question 5

Heptamer of Apaf1 proteins that forms on activation of the intrinsic apoptotic pathway; it recruits and activates initiator caspases that subsequently activate downstream executioner caspases to induce apoptosis.

Answer 5

apoptosome

Question 6

A main effector Bcl2 family protein of the intrinsic pathway of apoptosis in mammalian cells that is bound to the mitochondrial outer membrane even in the absence of an apoptotic signal; activation is usually by activated pro-apoptotic BH3-only proteins.

Answer 6

Bak

Question 7

A main effector Bcl2 family protein of the intrinsic pathway of apoptosis in mammalian cells; located mainly in the cytosol and translocates to the mitochondria only after activation - usually by activated pro-apoptotic BH3-only proteins.

Answer 7

Bax

Question 8

Anti-apoptotic Bcl2 family protein of the outer mitochondrial membrane that binds and inhibits pro-apoptotic Bcl2 family proteins and prevents inappropriate activation of the intrinsic pathway of apoptosis.

Answer 8

Bcl2

Question 9

Family of intracellular proteins that either promote or inhibit apoptosis by regulating the release of cytochrome c and other mitochondrial proteins from the intermembrane space into the cytosol.

Answer 9

Bcl2 family

Question 10

Anti-apoptotic Bcl2 family protein of the outer mitochondrial membrane that binds and inhibits pro-apoptotic Bcl2 family proteins and prevents inappropriate activation of the intrinsic pathway of apoptosis.

Answer 10

BclXL

Question 11

The largest subclass of Bcl2 family proteins. Produced or activated in response to an apoptotic stimulus and promote apoptosis mainly by inhibiting anti-apoptotic Bcl2 family proteins.

Answer 11

BH3-only proteins

Question 12

Intracellular protease that is involved in mediating the intracellular events of apoptosis.

Answer 12

caspase

Question 13

Soluble component of the mitochondrial electron-transport chain. Its release into the cytosol from the mitochondrial intermembrane space also initiates apoptosis. (Figure 14–26)

Answer 13

cytochrome c

Question 14

Transmembrane receptor protein that can signal the cell to undergo apoptosis when it binds its extracellular ligand. (Figure 18–5)

Answer 14

death receptor

Question 15

Activation complex in which initiator caspases interact and are activated following binding of extracellular ligands to cell-surface death receptors in the extrinsic pathway of apoptosis.

Answer 15

death-inducing signaling complex (DISC)

Question 16

Pro-apoptotic proteins of the intrinsic pathway of apoptosis that in response to an apoptotic stimulus become activated and aggregate to form oligomers in the mitochondrial outer membrane - inducing the release of cytochrome c and other intermembrane proteins. Bax and Bak are the main effector Bcl2 family proteins in mammalian cells.

Answer 16

effector Bcl2 family proteins

Question 17

Apoptotic caspases that catalyze the widespread cleavage events during apoptosis that kill the cell.

Answer 17

executioner caspases

Question 18

Pathway of apoptosis triggered by extracellular signal proteins binding to cell-surface death receptors.

Answer 18

extrinsic pathway

Question 19

Transmembrane death receptor that initiates apoptosis when it binds its extracellular ligand (Fas ligand). (Figure 18–5)

Answer 19

Fas (Fas protein - Fas death receptor)

Question 20

Ligand that activates the cell-surface death receptor - Fas - triggering the extrinsic pathway of apoptosis.

Answer 20

Fas ligand

Question 21

Intracellular protein inhibitors of apoptosis.

Answer 21

inhibitors of apoptosis (IAPs)

Question 22

Apoptotic caspases that begin the apoptotic process - activating the executioner caspases.

Answer 22

initiator caspases

Question 23

Pathway of apoptosis activated from inside the cell in response to stress or developmental signals; depends on the release into the cytosol of mitochondrial proteins normally resident in the mitochondrial intermembrane space.

Answer 23

intrinsic pathway (mitochondrial pathway)