lecture 37 vesicle transport in neurons

8/17/2019 Lecture 37 Vesicle Transport in Neurons

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1

B. Katz

Lecture 37:

vesicle transport

and the

neuromuscular

junction


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Announcements! And other important info!

• Last lecture quiz today

• Lab presentations today

•

Lab notebooks, hard copy andvirtual, due today

• Creative Biology assignment 5/

• evie" session poll "ill be posted

• #inal $%am &onday 5/'', ( am

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Lodish et) al, Molecular Cell Biology)

*sing mutant yeast to identi+y proteins involved in the

secretory path"ay

For each class of mutant:

A. Determine which part of the pathway is defective

B. Identify multiple proteins that could be defective in each case

3


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4

Non-peptide

(e.g. Ach)

Peptide (e.g.

endorphins)

n a motor neuron, "hat types o+ cargo need to be

transported to the a%on terminus-


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Coupled transport

Molecular Biology of the Cell (© Garland Science 2008)


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.econdary active transport

Molecular Biology of the Cell (© Garland Science 2008)

∆G’ > 0 for transport of X

∆G’ < 0 for another reaction

∆G’ < 0

6


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e%tracellular space

cytosol

.econdary active transport 0a1 / glucose symporter

7


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Na+

Na+Choline/Na+ symporter

Post-synaptic

muscle cell

Acetylcholinereceptor

Vesicular acetylcholine/H+ antiporter

Acetylcholine

H+H+H+

Vesicle containingacetylcholine

H+

ATP

ADP

Axon terminus

Pre-synapticmotor neuron

Glucosetransporter

H+

H+

H+

ATPasepump H

+

H+

ADP ATP

H+

Vesicle

Microtuule-

+

-

+

Voltage-gate!Ca"+ channel

Ca"+

Ca"+

Ca"+

Ca"+

8

Copyright © 2011 Wolters Kluwer Health ippincott Willia!s " Wil#ins

&odel 23 acetylcholine packaging and release


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Na+


Post-synapticmuscle cell



Acetylcholine

H+H+H+


H+

ATP

ADP

Axon terminus


Glucose

transporter

H+

H+H+ ATPasepump

H+H+

ADP ATP

H+

Vesicle

Microtuule-

+

-

+


Ca"+

Ca"+

Ca"+

Ca"+

9

Copyright © 2011 Wolters Kluwer Health ippincott Willia!s " Wil#ins

4hich o+ the +ollo"ing "ould result +rom inhibition o+ the

0a1/ 1 A67ase-

A. Acetylcholine could not

be synthesized

B. H+ would not move

through the

acetylcholine

antiporterC. Acetylcholine would

not be transported into

the synaptic vesicle

D. Choline could not betransported back into

the axon terminus

E. More than one of the

above is correct


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egulation o+ vesicle docking and +usion .0A$s


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&odel 2' Ca81, .0A$s, and vesicle +usion


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Botulism to%in is a protease that cleaves synta%in and

.0A7) 9o" might this a++ect synaptic vesicles-

A. Vesicles could fuse with plasma membranes in the absence of Ca2+

B. Vesicles would be unable to stably interact with the plasma membrane

C. Ca2+ would be unable to bind synaptotagmin

D. T-SNAREs would be unable to interact with v-SNAREs

E. More than one of the above is correct


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Na+





Acetylcholine

H+H+

H+


H+

ATPADP

Axon terminus


Glucosetransporter

H+

H+H+ ATPase

pumpH+

H+

ADPATP

H+

Vesicle

Microtuule-

+

-

+


Ca"+

Ca"+

Ca"+

Ca"+

6here is an inactivating mutation in the 91/acetylcholine

antiporter in the a%on terminal o+ a motor neuron) 4hich

o+ the +ollo"ing is true-

A) 6here "ill be a lack o+ 91 in the

secretory vesicles)

B) Acetylcholine cannot be

transported inside a vesicle)

C) 6here "ill be less release o+acetylcholine +rom the motor

neuron in response to an

upstream action potential)

:) 6here "ill be decreased +usion o+

vesicles "ith the plasma

membrane o+ the motor neuron in

response to calcium in+lu% into

the cytosol)

$) &ore than one o+ these is correct)


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:r) #rankenstein +ound a "ay to reanimate a monster

assembled +rom dead body parts he +ound "hile sneaking

around in graveyards) 9e believes that i+ he adds a mutant

synaptotagmin that is al"ays activated in the presence orabsence o+ Ca81 ions, the monster "ill be able to move)

4hy is he "rong, +ocusing entirely on the interactions

bet"een the motor neuron and the muscle cell-

Na+





Acetylcholine

H+H+H+


H+

ATP

ADP

Axon terminus


Glucosetransporter

H+

H+H+ ATPasepump

H+

H+

ADP ATP

H+

Vesicle

Microtuule

-

+

-

+


Ca"+

Ca"+

Ca"+

Ca"+


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lecture 37 vesicle transport in neurons

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