Exploitaion of the actin cytoskeleton by Listeria

Question 1

What is alpha-actinin?

Answer 1

a cross linking protein

Question 2

What does Listeria express?

Answer 2

ActA at pole of bacterium

Question 3

What happens when ActA binds actin in the host cytoplasm?

Answer 3

it is only sufficient to allow limited motility

Question 4

What is required for full motility?

Answer 4

VASP binding (proline-rich region of protein)

Question 5

What does VASP do?

Answer 5

recruits Arp complexes –> increases comet tail formation

binds profilin –> good ATP-containing G actin molecule supply for polymerisation

Question 6

How does Listeria bind to the host cell?

Answer 6

Outside –> via E-cadherin

Question 7

What does Listeria binding trigger?

Answer 7

Normal endocytosis/phagocytosis mechanisms

Question 8

How does Listeria access the cytoplasm?

Answer 8

once bacteria inside phagolysosome –> produces lysin proteins –> breaks down organelle membrane –> Listeria accesses cytoplasm

Question 9

How does Listeria move through the cell + between cells?

Answer 9

intracellular motility