Apoptosis

Question 1

description of chromatin change seen in apoptosis

Answer 1

chromatin condense peripherally (under nuclear membrane)

Question 2

what are capsases?

Answer 2

cysteine proteases (hydrolyze proteins)

Question 3

what do caspases cleave? what does this cause?

Answer 3

nuclear and cytoskeleton scaffold; protein cross-linking and cytosolic condensation

Question 4

caspases trigger this activity

Answer 4

endonuclease

Question 5

these are responsible for DNA breakdown associated with caspases

Answer 5

Ca and Mg dependent endonucleases

Question 6

when this molecule is ‘flipped’ and located on outside of cell membrane, cell recognized for phagocytosis of apoptotic bodies

Answer 6

phosphatidylserine

Question 7

in addition to phosphatidylserine, this molecule may also play a role in triggering phagocytosis when expressed on outside

Answer 7

thrombospondin

Question 8

these two pathways initiate apoptosis signaling

Answer 8

Bcl and Fas-Fas signaling

Question 9

where do Bcl-2 family proteins reside?

Answer 9

mitochondrial membrane

Question 10

what do Bcl-2 family proteins cause in mitochondria?

Answer 10

swelling (due to increased membrane permeability)

Question 11

this determines permeability of mitochondrial membrane

Answer 11

ratio anti:pro-apoptotic Bcl2

Question 12

BH3 only proteins that are activated by cytoplasmic sensors

Answer 12

bim, bad, bid

Question 13

anti-apoptotic proteins –> blocked by BH3 only proteins

Answer 13

bcl-2 and bcl-x

Question 14

follicular lymphomas have oncogene that activates this (Inhibits apoptosis)

Answer 14

bcl-2

Question 15

pro-apoptotic proteins that insert into mitochondrial membrane to form pores

Answer 15

bax and bak

Question 16

what does cytochrome C bind to when released from mitochondrial outer membrane? what does this activate?

Answer 16

Apaf-1; caspase 9

Question 17

death receptors are members of this signaling pathway

Answer 17

TNF

Question 18

cross-linking of this surface receptor by TNF initiates Fas-Fas death receptor pathway

Answer 18

TNFR1

Question 19

this expression results in binding of FasL on self-reactive or cytotoxic T cells (viral) –> triggering apoptosis

Answer 19

Fas/CD95

Question 20

activated surface ligand–> integration of death domain into receptor –> what is activated as a result?

Answer 20

FADD and pro caspase 8

Question 21

some viruses produce this that blocks activation of caspase 8

Answer 21

FLIP

Question 22

what does FLIP block activation of?

Answer 22

caspase 8

Question 23

final common pathway for apoptosis

Answer 23

activation of proteolytic cascade

Question 24

what results due to final common pathway of proteolytic cascade in apoptosis?

Answer 24

disruption cytoskeleton and nuclear matrix, activation internucleosomal cleavage of DNA

Question 25

expression of this inhibits phagocytosis in live cells

Answer 25

CD31

Question 26

aka FADD

Answer 26

Fas associated death domain

Question 27

activated TNF receptor binds this –> activates caspase pathway

Answer 27

FADD or TRADD

Question 28

ligand expressed by activated CTLs

Answer 28

FasL

Question 29

what may occur as result of transmembrane pore formation due to exchange perforins in Cytotoxic T cell mediated cell death?

Answer 29

release granzyme B, activates caspase cascade in target cell

Question 30

mediates apoptosis due to GF deprivation

Answer 30

decrease bcl-2 or activation pro-apoptotic signals

Question 31

triggers apoptosis due to DNA damage

Answer 31

p53

Question 32

this labels misfolded proteins; where are they degraded?

Answer 32

ubiquitin; proteosomes

Question 33

accumulation of misfolded proteins leads to the unfolded protein response, which causes what?

Answer 33

ER stress (which activates caspases)