Apoptosis/Stem Cells

Question 1

complexes with cytochrome c and ATP to activate caspase-9

Answer 1

Apaf-1

Question 2

Apaf-1/ATP/Caspase-9/cytochrome c complex

Answer 2

Apoptosome

Question 3

Bcl-2 family members that induce apoptosis by inhibiting activity of anti-apoptotic proteins

Answer 3

Bad and Bid

Question 4

Bcl-2 family member that induces apoptosis when translocated to mitochondria

Answer 4

Bax

Question 5

family of genes involved in apoptosis; some inhibit apoptosis and others promote apoptosis

Answer 5

Bcl-2

Question 6

formation of irregular bulges in the plasma membrane of a cell during apoptosis

Answer 6

blebbing

Question 7

proteases involved in apoptosis; contain cysteine residue at active site and cleave after aspartate in substrate

Answer 7

caspases

Question 8

amino acid sequence present on C-terminus of both Fas and FADD

Answer 8

death domain

Question 9

Amino acid sequence present on N-terminus of both FADD and pro-caspase-8

Answer 9

DED

Question 10

complexes to fas and pro-caspase-8 when fas is stimulated

Answer 10

FADD

Question 11

Cell surface receptor in immune cells that binds a ligand leading to apoptosis

Answer 11

Fas

Question 12

negative regulator of apoptosis

Answer 12

FLIP

Question 13

inhibitor of apoptosis protein

Answer 13

IAP

Question 14

pro-apoptotic proteins released from mitochondrion that inhibit action of IAPs

Answer 14

Smac/Diablo

Question 15

True or false: apoptosis is reversible once the process has started

Answer 15

false

Question 16

what signals for apoptosis

Answer 16

phosphatidylserine

Question 17

phagocytose apoptotic cells

Answer 17

macrophages and neighboring cells

Question 18

how are caspases activated?

Answer 18

the inactive form is cleaved by other caspases

Question 19

_____ caspases activate ____ caspases, which can then activate other ____ caspases

Answer 19

initiator; executioner; executioner

Question 20

Four things caspases cleave

Answer 20

1) inhibitors of DNase that cleave genomic DNA between nucleosomes
2) nuclear lamin
3) cytoskeletal proteins
4) inhibitors of apoptosis

Question 21

Two apoptotic pathways

Answer 21

1) Intrinsic/stress

2) extrinsic/death receptors

Question 22

How do antiapoptotic proteins work

Answer 22

they sequester pro-apoptotic proteins

Question 23

How do the proapoptotic proteins Bad/Bid work

Answer 23

block Bcl-2 and Bcl-xL interaction with pro-apoptotic proteins

Question 24

Two antiapoptotic members of the Bcl-2 family

Answer 24

Bcl-2 and Bcl-xL

Question 25

Two proapoptotic members of the Bcl-2 family

Answer 25

Bad, bid

Question 26

How do the proapoptotic proteins Bak/Bax work

Answer 26

translocate to the mitochondria, where they insert in the membrane and disrupt its integrity, allowing cytochrome c to be released

Question 27

Causes dimerization of procaspase-9, creating active caspase-9 dimers

Answer 27

apoptosome

Question 28

Catalyzed by proteolytic activation by capase-9, these two proteins lead to the death of the cell in the intrinsic/mitochondrial pathway

Answer 28

Caspase-3 and caspase-7

Question 29

How does Fas trimerize in the extrinsic pathway?

Answer 29

membrane-bound FasL (ligand) on surface of one cell binds to Fas on target cell, recruiting adaptor FADD (bound via death domain on both)

Question 30

What does the FADD death effector domain at the N-terminus (aka not bound to Fas) bind to to activate?

Answer 30

pro-caspase 8

Question 31

Where is the death domain and where is the death effector domain?

Answer 31

death domain: C-termini of both Fas and FADD adaptor | death effector domain: N-terminus of FADD and caspase-8

Question 32

when activated what is removed from caspase-8

Answer 32

N-terminal DED

Question 33

What does caspase-8 do at the end of the extrinsic pathway?

Answer 33

activate downstream caspases

Question 34

Besides its role in the extrinsic pathway, what does caspase-8 activate?

Answer 34

Caspase-1 (which leads to other caspases and cell substrates) and Bid

Question 35

Bid is normally inactive in the cytosol but when its cleaved it translocated to...

Answer 35

the mitochondria, where it disrupts the membrane to let cytochrome c out and feed into the intrinsic pathway

Question 36

They bind to procaspases to prevent their activation and bind to caspases to inhibit their activity

Answer 36

Inhibitors-of-Apoptosis Proteins (IAPs)

Question 37

What do Reaper, Hid, and Grim do?

Answer 37

Inhibit IAPs

Question 38

Similar in structure to caspase-8 but lack catalytic residues. Compete with caspase-8 for binding to FADD. . Negative regulator of apoptosis

Answer 38

FLIPs

Question 39

Bind to apoptosis-inducing ligand but cannot transduce apoptotic signal.

Answer 39

Decoy receptors

Question 40

Initiates transcription of pro-apoptotic genes PUMA and Noxa after being activated by DNA damage

Answer 40

p53

Question 41

Phopsphorylate, activate, and stabilize p53

Answer 41

ATM and Chk2 protein kinases

Question 42

Excessive/inappropriate apoptosis can lead to (5)

Answer 42

1. neurodegenerative diseases 2. immune deficiency diseases 3. cardiovascular disease 4. emphysema 5. AIDS

Question 43

Too little apoptosis can lead to (2)

Answer 43

1. cancer | 2. autoimmune diseases

Question 44

Two ways cancer affects the apoptotic pathways

Answer 44

IAP expression increased and anti-apoptotic Bcl-2 protein levels increased

Question 45

Cancer treatment strategies involving reactivating apoptosis (3)

Answer 45

1. BH3 mimetics 2. XIAP antagonists 3. FasL mimetics and Fas activators