8 - SNAREs I - membrane fusion machinery

Question 1

How can sensory vesicles be visualised?

Answer 1

BY electron microscopy.

Question 2

What are the 3 main approaches to identify the machinery of vesicle transport?

Answer 2

1 - Biochemical reconstitution.
2 - Yeast genetics
3 - Cloning

Question 3

What is biochemical reconstitution?

Answer 3

Takings a cell apart and putting it together to identify various functions.

Question 4

How many SNAREs are encoded in the human genome?

Answer 4

38 all involved in various transport steps and fusion reactions.

Question 5

What SNAREs wrap around each other to form a complex?

Answer 5

SNAP25, Syntaxin and VAMP (wrap around in a similar way to an alpha helix)

Question 6

What does SNARE zippering provide?

Answer 6

Energy to drive membrane function.

Question 7

What 2 categories can SNAREs be divided into?

Answer 7

Q and R SNAREs.

Question 8

What type of SNARE is VAMP?

Answer 8

An R SNARE whilst the rest are Qs.

Question 9

What is the Q to R SNARE ratio that is seen in most complexes?

Answer 9

3Q:1R

Question 10

What are some common features of SNARE proteins?

Answer 10

• Generally small (14-40 kDa)
• they all have at least 1 coiled-coil or SNARE motif.
• C-terminally anchored