Structure related proteins

Question 1

Formin

Answer 1

1. nucleation factor of actin protofilament (foreman)

2. (+) asociation

Question 2

Thymosin

Answer 2

1. prevent actin protofilament assembly by binding to the free monomers

Question 3

Profilin

Answer 3

1. binds to actin monomers and increase protofilament elongation

Question 4

Arp Complex

Answer 4

1. consist of ARP2/3, binds to existing protofilament.

2. elongates at 70 degrees from minus end of existing structures

Question 5

Cofilin

Answer 5

Binds to ADP-actin monomer and increases disassembly

Question 6

Tropomyosin

Answer 6

binds to protofilament and adds stability

Question 7

Fimbrin

Answer 7

provides cross-linking to form filopodia

Question 8

alpha-actinin

Answer 8

attach actin to the Z-line, required for muscle contraction

Question 9

filamin

Answer 9

helps to maintain the angle of actin protofilaments at 70 degrees

Question 10

ERM

Answer 10

stabilize protofilament in the cell cortex with respect to cell mitosis

Question 11

Gamma-TuRc

Answer 11

nucleates assembly of microtubule (-)

Question 12

Kinesin-13

Answer 12

1. aids in catastrophe of microtubules. increasing the free concentration of alpha-beta subunits

Question 13

XMAP215:

Answer 13

stabilizes the (+) and therefore increases polymerization

Question 14

MAPs

Answer 14

stabilize microtubule by binding to the side

Question 15

MAP2

Answer 15

causes loose bundle formation so myosin can penetrate in between. Has a long outward projeciton, and microtubule binding site

Question 16

Tau

Answer 16

consist of microtubule bundling protein. association packs microtubules tightly together. 2 microtubule binding domains and short outward projection

Question 17

Plectin

Answer 17

helps link microtubule tips to other molecules or proteins