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Flashcards in Vesicular transport Deck (20):
1

What does the vesicular pathway look like?

E=exo, G=endo R=retrieval
Endoplasmic reticulum
ER
Golgi apparatus
ER E ER
late endosome sec. vesicl
GR G E E
lysosome
G E E
early endo.
GR R E E
Rec endo.
GR R E E
Extracellular space

2

How many well known coat proteins are there?

Four.

3

Name the four well characterized coat proteins that Dr adams mentioned.

Clathrin
COP I (coatamer protein 1)
COP II (coatemer protein 2)
Retromer

4

Are there multiple types of clathrin?

yes.

5

trans vs cis Golgi networks.

trans exports towards the plasma membrane.
cis takes imports from the ER

6

Where are the following found.
Clathrin
COP I
COP II
Retromer

Clathrin: PM and trans-Golgi
COP I: cis-Golgi
COP II: ER
Retromer:

7

What are v-SNAREs, and t-SNAREs involved in?

v-SNAREs are on vesicles, they bind to T-SNAREs which exist on surface of the cellular compartments. They make a docking complex.

8

What is the basic structure of clathrin?

It has three heavy chains with smaller light chains binding near the connecting point to the heavy chains. The heavy chains interconnect to form the helical structure.

9

Explain how the below are involved in bud formation.
Cargo Receptors
Cargo molecules
clathrin
adaptins

Cargo molecules bind to their cargo protein (which is in the ER lumen). This allows them to bind an adaptor protein. This protein allows clathrin to bind, which binds to other clathrins holding cargo receptors next to each other while causing a vesicle to form.

10

What happens to clathrin and adaptin shortly after vesicle formation?

They break off the vesicle and are recycled.

11

Where does retromer assemble?

On endosomes.

12

Where does the retromer retrieval pathway return material to?

The golgi apparatus.

13

Why does retromer dimerize?

To make the curvature necessary for a cell.

14

What are the four subunits of retromer.

SNX1
VPS29
VPS35
VPS26

15

What do the subunits below do?
SNX1
-BAR domain
-PX domain
VPS29
VPS35
VPS26

SNX1: point of dimerization
-BAR domain: attachment point
-PX domain: Binds to phophoinositide in the membrane
VPS29:
VPS35:
VPS26:

16

Are the domains unique to SNX1?
-BAR domain
-PX domain

No, they are found in many other proteins.

17

How many different form of phosphinositides are possible to make?

There are 8 different combination that can be made through phosphorylation and dephosphorylation.

18

Why does it matter the number of phosphinositides exist?

Each binds different proteins.

19

What is dynamin.
What does dynamin do?

it is a monomeric GTPase.

it pinches of the 'neck' of a forming vesicle. Then causes it to pinch off, vesicle scission.

20

Mutations of dynamin can cause it to do what?

Mutation can cause failure of scission, or increased scission.

Drosophila mutant shibire, paralyzed because it cannot recycle (endocytose) its vesicles back into the cell.