BI203 Lecture 24: Apoptosis (Slides 14 - 23)

Question 1

___ are the ultimate executioners of programmed cell death by cleaving over 100 different target proteins.

Answer 1

Caspases

Question 2

Activation of a(n) ___ ___ starts a chain reaction of caspase activation leading to death of the cell.

Answer 2

initiator caspase

Question 3

___ = Inhibitor of CAD.

Answer 3

ICAD

Question 4

Caspases inhibit ICAD, leading to ___ ___.

Answer 4

DNA fragmentation

Question 5

Caspases cleave nuclear lamins, leading to ___ ___.

Answer 5

nucleus fragmentation

Question 6

Caspases cleave cytoskeletal proteins, leading to ___ ___.

Answer 6

cell fragmentation

Question 7

Caspases cleave Golgi matrix proteins, leading to ___ ___.

Answer 7

golgi fragmentation

Question 8

Caspases activate the protein ___, which translocates phosphatidylserine to the outer leaflet.

Answer 8

scramblase

Question 9

There are ___ types of caspases.

Answer 9

2

Question 10

The 2 types of caspases:

Answer 10

initiator caspases and effector caspases

Question 11

Key initiator caspase in mammals:

Answer 11

Caspase-9

Question 12

Caspase-9 is activated by forming a complex with Apaf-1 and cytochrome c into a complex called the ___.

Answer 12

apoptosome

Question 13

Key effector caspase in mammals:

Answer 13

Caspase-3

Question 14

Effector caspases (e.g., Caspase-3) are activated through ___ by Caspase-9.

Answer 14

cleavage

Question 15

Inactive caspases = ___.

Answer 15

procaspases

Question 16

___ ___ release from mitochondria induces caspase activation during apoptosis.

Answer 16

cytochrome c

Question 17

Cytochrome c release is regulated by the ___ family of proteins.

Answer 17

Bcl-2

Question 18

The Bcl-2 family contains BOTH ___ and ___ proteins.

Answer 18

pro-apoptotic, anti-apoptotic

Question 19

All Bcl-2 proteins have one or more ___ (Bcl-2 Homology) domains.

Answer 19

BH

Question 20

___ and ___ can also stimulate cytochrome c release. ___ and ___ are inhibited by anti-apoptotic Bcl-2 proteins.

Answer 20

Bax, Bak

Question 21

___ proteins are activated at the start of apoptosis -> They bind and displace anti-apoptotic Bcl-2 proteins.

Answer 21

BH3-only proteins

Question 22

Caspase-9 is activated by forming a complex with ___ and ___ ___ in a complex called the apoptosome.

Under normal conditions, cytochrome c is in the mitochondrial ___ ___, while Apaf-1 and Caspase-9 are in the ___. Thus, Caspase-9 remains inactive under normal conditions.

Answer 22

Apaf-1, cytochrome c, intermembrane space, cytosol