Vesicular transmitter release III

Question 1

Role of Munc18?

Answer 1

Acts like the clasp on a zipper–> helps “zip” the coils together

Question 2

Specific thing done by Munc18?

Answer 2

Catalyses a stepwise zippering of the SNARE bundle to help pull the two membranes together

Question 3

What exerts the pore formation?

Answer 3

the SNARE complex driving formation of a fusion pore

Question 4

Cis snare complex?

Answer 4

Vesicle membrane has attached to cell membrane on both sides of a now opened pore

Question 5

What happens before formation of the full fusion pore?

Answer 5

There is a hemi-fused state–> partial mix between the vesicular and plasma membrane

Question 6

Importance of hemi fused pore state?

Answer 6

It is the prime state that can be triggered v arpidly from calcium influx

Question 7

Which protein stabilises the hemi fused state of the pore complex?

Answer 7

Complexin–> arrest fusion in a hemi fused state–>inner but not otuer leaflets are fused

Question 8

How is complexin displaced from the SNARE complex?

Answer 8

Synaptotagmin, in the presence of Ca2+

Question 9

What is the calcium sensitive trigger in the fusion of a vesicle to the synaptic terminal membrane?

Answer 9

Synaptotagmin

Question 10

EFfect of clathrin mediated endocytosis?

Answer 10

Can delay further transmission bc refilling process is slow

Question 11

Fastest form of endocytosis?

Answer 11

Ultrafast endocytosis

Question 12

What is kiss and run?

Answer 12

Full fusion does not occur–> partial fusion which allows rapid recycling

Question 13

What triggers release of vesicles from the cytoskeleton?

Answer 13

Synapsin phosphorylation

Question 14

What are the triggers for synapsin phosphorylation, and what are they sensitive to?

Answer 14

Calmodulin kinase II (CamKinaseII)
Members of the MAP kinase family
both sensitive to calcium