Actin Accessory Proteins

Question 1

What nucleates assembly and remains associated with the growing plus end?

Answer 1

Formin

Question 2

What nucleates assembly to form a web and remains associated with the minus end?

Answer 2

ARP complex

Question 3

What binds subunits & speeds elongation?

Answer 3

Profilin

Question 4

What stabilizes the filament?

Answer 4

Tropomyosin

Question 5

What prevents assembly & disassembly at the plus end?

Answer 5

Capping protein

Question 6

What severs filaments and binds to the plus end?

Answer 6

Gelsolin

Question 7

What binds ADP-actin filaments, & accelerates disassembly?

Answer 7

Cofilin

Question 8

What binds subunits & prevents assembly?

Answer 8

Thymosin

Question 9

What cross links actin filaments into tight bundles so myosin II can’t bind?

Answer 9

Fimbrin

Question 10

What cross links actin filaments into loose bundles, so myosin II can bind?

Answer 10

Alpha-actinin

Question 11

What forms a flexible high angle link between two actin filaments that forms a mechanically strong web

Answer 11

Filamin

Question 12

What attaches actin filaments to plasma membrane?

Answer 12

ERM

Question 13

What forms a web in red blood cells that creates a stiff cortex?

Answer 13

Spectrin