2.9 Intracellular Vesicular Trafficking 2

Question 1

What happens in the R ER?

Answer 1

Ribosomes feed proteins through the Sec61 translocator

Question 2

What happens in the R ER lumen?

Answer 2

Proteins are folded and gain sugar

Question 3

Why is the S ER smooth?

Answer 3

Lacks ribosome association

Question 4

What happens in the S ER?

Answer 4

Where vesicles bud from when cargo needs to go to the golgi

Question 5

What happens in the S ER lumen?

Answer 5

Lipids gain sugar

Question 6

What happens to folded and misfolded proteins that want to leave the ER?

Answer 6

Misfolded proteins go to the cytosol for degradation. Folded proteins go to the golgi for sorting.

Question 7

Misfolded proteins go to the cytosol to be degraded via what?

Answer 7

Translocator

Question 8

Folded proteins go to the Golgi for sorting via what?

Answer 8

Vesicles.

Question 9

What proteins would return to the ER? For what Reason?

Answer 9

Rabs, SNAREs and cargo receptors must all go back for recycling.

Question 10

What is the sorting seq for Rabs,SNAREs and cargo receptors?

Answer 10

KK??

Question 11

What is the sorting seq for ER lumen resident proteins?

Answer 11

KDEL

Question 12

What is homotypic fusion?

Answer 12

Many vesicles uncoat and duze with other vesicles. Forming these clusters.

Question 13

Going from the ER to the Golgi, what part of the golgi is reached first?

Answer 13

Cis then the trans.

Question 14

What part of the golgi goes to a lysosome?

Answer 14

Trans

Question 15

What is autophagy?

Answer 15

Digestion of organelles by the lysosome

Question 16

What are the 3 types of Endocytosis?

Answer 16

Receptor mediated, Phagocytosis, and pinocytosis

Question 17

Pertaining to receptor mediated endocytosis, what coat does it use? Budding?

Answer 17

Clathrin, and Actin.

Question 18

Pertaining to receptor mediated endocytosis, what is the cargo selection and cargo?

Answer 18

Receptor and cargo is specific to receptor

Question 19

Pertaining to receptor mediated endocytosis, what is a good example?

Answer 19

Cholesterol uptake

Question 20

Pertaining to phagocytosis, what is the coat and budding?

Answer 20

No coat. Budding is pseudopod

Question 21

Pertaining to phagocytosis, what is the cargo selection and cargo?

Answer 21

Antibody and the cargo is whole cell/large molecules

Question 22

Pertaining to phagocytosis, what is a good example?

Answer 22

Antigen presentation

Question 23

Pertaining to pinocytosis, what are the 3 coats used with their select buddings?

Answer 23

1. Clathrin:amphi+Actin. 2. Claveolin: lipid composition. 3. No coat: actin.

Question 24

Pertaining to pinocytosis, what is the cargo selection and cargo?

Answer 24

Not selective and usually bulk fluid and small molecules.

Question 25

Pertaining to pinocytosis, what are the kinetics for the 3 coats?

Answer 25

Clathrin: fast. Claveolin:Slow. No coat: induced.

Question 26

Once inside the cell what happens to vesicles?

Answer 26

Vesicle will fuse into an endosome, they mature to get to a lysosome. (Not dealing with coats.)

Question 27

What is the Early endosome? What does it contain?

Answer 27

Also called sorting endosome. Has Rab5.

Question 28

What is the EE mediated by?

Answer 28

ESCRT

Question 29

What are some other functions of ESCRT?

Answer 29

Part of autophagy pathway, help remove protein coats, helps with budding viruses, exosome formation, and bridging between cells

Question 30

What does the recycling endosome (RE) contain?

Answer 30

Rab11

Question 31

What does the late endosome (LE) contain?

Answer 31

Rab 7

Question 32

What are the 3 possible fates of vesicles leave the trans golgi?

Answer 32

1. Lysosome. 2/3 basically exocytosis.

Question 33

What coat do all vesicles that leave the golgi get?

Answer 33

Clathrin coat

Question 34

What happens if the lysosomes arnt working well?

Answer 34

Inability to break down whats inside the lysosome. Resulting in release (exocytosis) of these micro vesicles (little exosomes).

Question 35

What are some clinical implications if the lysosomes dont work well? What are some example of these diseases?

Answer 35

Neurodegenerative diseases. Alzheimers.