CBG Lecture 36: Vesicular Traffic Flashcards Preview

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Flashcards in CBG Lecture 36: Vesicular Traffic Deck (67)
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1

what are the main experiments that led to the concept of trafficking

pulse chain:radioactivity
GFP - encoded by cDNA then attach GFP tag to viral glycoprotein VSVG - use glycoprotein as this will undergo postranslational modification - in Golgi

2

why do proteins move

prevent depletion of organelle-resident proteins
prevent depletion of lipids

3

what is KDEL sequence

Golgi to ER signalling sequence

4

where must proteins destined for the signalling pathway go

to the RER

5

via what do proteins enter the RER

via SRP signal peptide recognition partice

6

where does synthesis and modification of proteins occur

RER

7

where does synthesis of lipids occur

SER

8

where does calcium storage occur

sarcoplasmic reticulum in muscle cells

9

how does vesicular transport betwen compartments occur

budding and fusion

10

what are the different types of protein vesicle coats

clathrin
COPI
COPII

11

what do protein coats do

organise vesicular traffic and give shape to vesicles and concentrate membrane proteins in a specialised patch

12

what is a vesicle coat

a small membrane bounded organelle with a cage of proteins (coat) on its cytosolic surface.
formed by piclking off of a coated region of membrane - coated pit

13

where do clathrin coats mediate transport to

golgi
PM

14

where do COPI coats mediate transport to

ER and Golgi cisternae

15

what are the major components of clathrin coated vesicles

clathrins and adaptins
each clathrin unit has 3 large heavy and 3 light pp chains that form a triskelion

16

where is triskelion found
what is it made up of

triskelion found in clathrin coated vesicles
made up of 3 large heavy and 3 light pp chains
alpha zigzag and beta propellor- 36 triskelions make up a hexagonal clathrin cage

17

what can isolated triskelions do

self assemble sponatenously

18

what are adaptin proteins

requierd to bind the clathrin coat to membrane and to trap transmembrane receptors that capture soluble cargo molecules

19

outline the structure of clathrin

alpha zigzag
beta propeller makes the triskelion
36 triskelions make up a hexagonal clathrin cage

20

how many triskelions make up a hexagonal clathrin cage

36

21

discuss assembly and disassembly of clathrin coat

assembly of coat thought to induce curvature into membrane, which leads to formation uniformly sized coated buds
2.adaptins bind both clathrin triskelions adn membrane bound cargo receptors, thereby mediating the selective recruitment of both membrane and cargo molecules into the vesicle
3. ARF GTPase initiastes assembly
4. dynamin pinches off vesicle
5.ARF switching and Hsc70 ATP hydrolysis triggers uncoating of vlathrin

22

which enzymes initiate assembly of clathrin coated vesicles

ARF GTPase

23

which enzymes trigger uncoating of clathrin coated vesicles

ARF switching
and Hsc70 ATP hydrolysis

24

what are the four adaptor proteins present in clathrin coated vesicles

AP1 AP3 AP2 GGA

25

which adaptor proteins are involved in movement from TGN trans golgi network to endosome

AP1 or GGA

26

which adaptor proteins are involved in movement from TGN to PM

AP2

27

which adaptor proteins are involved in movement from TGN to lysosomes

AP1

28

which adaptor proteins are involved in movement from PM to endosomes

AP2

29

what movement IS MEDIATED By AP1 or GGA

TGN to endosome

30

what movement is mediated by AP2

TGN to PM