L13 - The Cytoskeleton

Question 1

What are the three major classes of motor proteins?

Answer 1

Kinesins
Dyneins
Myosins

Question 2

What is cytoskeletal feature is important for LTD and LTP?

Answer 2

Myosin VI

Question 3

What are the kynesins important in neurons?

Answer 3

KIF5 and KIF3

Question 4

What do KIF5 and KIf3 do?

Answer 4

Transport mitochondria and synaptic vesicles

Question 5

Describe myosin II

Answer 5

Muscle myosin
Can only bind ti actin in it’s ado bound state
Power stroke is atp dependent
Only attached to the actin filament for a small percentage of the time

Question 6

Describe myosin V

Answer 6

Processive walking
Long lever arm about 30-40nm swing
Tight connection to actin

Question 7

Decribe myosin vi

Answer 7

Has a 180 degree powerstroke

Towards negative end

Question 8

What motor proteins can RabII bind?

Answer 8

Dynein
KIF5
MyoVb

Question 9

What is the Rab II to dynein adaptor?

Answer 9

FIP3 which binds to Rab II GTP

Question 10

What is the rab II kif5 adaptor?

Answer 10

Protrudin which binds to rab ii gdp

Question 11

What is the adaptor that binds myovb and rab ii?

Answer 11

Fip2 and if binds to rab ii gtp

Question 12

Outline calcium regulation of myosin v

Answer 12

Normally in Autoinhibited conformation apo-CaM.
When there is a high calcium concentration calcium binds activiating it. It then binds to actin and cargo and slow transit occurs.
When tehre is a low calcium concentration it activates then binds to actin/ atp and undergoes fast transit.

Question 13

What drives the exocytosis of AMPA receptors?

Answer 13

Myosin Vb

Question 14

Outline actin/myosins rule in endocytosis

Answer 14

Polymerize actin around the area on the membrane with the hell of myosin i, leading to cup formation. This is then transported back by myosin vi.

Question 15

Outline actin/myosin function in exocytosis

Answer 15

Myosin 1c Nd 1e in the early ateps
Myosin V follows the vesicle
Myosin vi is needed for the final phase

Question 16

What is Spir?

Answer 16

An actin nucleation factor which nucleates them directly onto recycling endosomes

Question 17

What would a formin mutation cause?

Answer 17

Intellectual problems. IQ below 70

Question 18

Describe Griscelli Syndrome I

Answer 18

Caused by a myosin va mutation it causes pigment dilution, profund neurological defects.

Question 19

How do you make a new dendritic spine?

Answer 19

Actin bends the membrane, this is elongated and nucleared by VASP.