Vesicular transmitter release II

Question 1

Vesicle fusion?

Answer 1

active fusion of the vesicle membrane with the plasma membrane to release vesicular contents when the local calcium reaches a threshold level

Question 2

Which vesicles fuse once the local calcium level crosses a threshold?

Answer 2

Primed vesicles

Question 3

Vesicular recycling mechanism?

Answer 3

Recycling - of vesicular membrane by endocytosis to form a new vesicle for transmitter filling

Question 4

Why do small molecules have to be synthesised in the nerve terminal?

Answer 4

Vesicles only operate in the nerve terminal

Question 5

Role of VAMP/synaptobrevin?

Answer 5

synaptic vesicle protein, central to vesicle fusion regulation

Question 6

Role of Synaptotagmin?

Answer 6

part of the control machinery involved in triggering of fusion event

Question 7

Use of SV2s, SCAMPs, synaptogyrin?

Answer 7

ID vesicles experimentally
promoters to drive expression of smthn in a nerve termina

Question 8

Why are SV2s, SCAMPs, synaptogyrin used as promoters?

Answer 8

They are ve selective to nerve terminal machinery and processes

Question 9

What type of molecule are RABs?

Answer 9

Small GTPases

Question 10

What is RAB3 involved in?

Answer 10

early docking and binding events

Question 11

Active form of RAB3?

Answer 11

GTP bound

Question 12

What does active (GTP bound) RAB3 bind to?

Answer 12

RIM plasma membrane protein

Question 13

What does RAB3 do after binding to RIM?

Answer 13

Form a scaffold w/ Munc13, rabphillin and calcium channels

Question 14

RAB3 involved scaffold role?

Answer 14

Ensures docking of the vesicle is close to the sensing machinery–> vesicle is close to site of calcium channel

Question 15

What are C2 domains?

Answer 15

Calcium and lipid binding domain

Question 16

Where are C2 domains often found?

Answer 16

Proteins involved in membrane signalling events

Question 17

What do fusion events require?

Answer 17

An N-ethylmaleimide (NEM) sensitive factor, called NSF

Question 18

What does the NEM sensitive factor have a requriement for?

Answer 18

ATP

Question 19

How were the proteins that associate with the NEM sensitive factor determined?

Answer 19

Affinity column processes–> NEM factor on a column, pass homogenate down the columns and see which proteins are pulled out

Question 20

What does SNAPs stand for?

Answer 20

Soluble NSF attachment proteins

Question 21

What does SNAREs stand for?

Answer 21

Soluble NSF attachment protein receptors

Question 22

Role of SNAREs?

Answer 22

Associate together to regulate vesicle fusion events

Question 23

Where does the VAMP part of the SNARE complex sit?

Answer 23

Vesicular membrane

Question 24

Where does the remaining (non-VAMP) proteins of the SNARE complex attach?

Answer 24

Recipient plasma membrane

Question 25

What is the SNARE complex?

Answer 25

A complex between the proteins on the vesicular membrane and the plasma membrane

Question 26

tSNAREs (targetSNAREs) examples?

Answer 26

Syntaxin I, SNAP25

Question 27

Syntaxin I?

Answer 27

Presynaptic plasma membrane protein (integral)

Question 28

SNAP25?

Answer 28

Presynaptic plasma membrane protein (anchored)

Question 29

vSNARE (vesicularSNAREs) e.g.?

Answer 29

Synaptobrevin

Question 30

Synaptobrevin localisation?

Answer 30

Vesicular membrane protein (integral)

Question 31

What is the structure of a synaptic SNARE complex?

Answer 31

four parallel helices

Question 32

Which molecules contribute to the four parallel helices in a synaptic SNARE?

Answer 32

Syntaxin and synaptobrevin contribute oen motif each, SNAP25 contributes two motifs

Question 33

Which toxins can affect proteins in the SNARE complex?

Answer 33

Botulinum toxin, tetanus toxin, clostridium toxin