Protein Trafficking

Question 1

3 basic intracellular transfer steps

Answer 1

1. budding of membrane 1 to form vesicle with what’s being transported inside
2. traveling through cell via actin/motors
3. Fusion of vesicle with membrane and release of contents into cell

Question 2

Clathrin, Cop I, Cop II

Answer 2

Protein coatings for pinching out/in and forming vesicles
Cop II: ER to Golgi
Cop I: Golgi to ER
Clathrin: cell membrane and endosomes

Question 3

AP-2 Complex

Answer 3

Binds to receptor. Receptor transduces a signal.

Question 4

CLATHRIN Mediated Endocytosis

Answer 4

1. Receptor binds to something.
2. Receptor sends signal.
3. AP2 binds to receptor signalling for vesicle to fold inward with receptor and what it’s bound to to come in.
4. Clathrin surrounds vesicle and pinches it off.
5. Clathrin and Receptor fall off and are reused

Question 5

COPII coated vesicle formation

Answer 5

Essentiall Exit from ER

1. Sar1 recruits COPII
2. Sec 12 is Gef that causes GDP/GTP exchange activating Sar1
3. Sar 1 then activated, embeds in the membrane with CopII
4. Cop II graps shit in the area and is signal to pinch off area, not as specific as Clathrin

Question 6

Rab-GTP/ Rab effectors

and v-SNARE and t-SNARE s

Answer 6

1. Specific Rab GTP and v-snare put on vesicle,

2. Rab effector (tethering protein) binds to Rab GTP and d

Question 7

How does shit bound to Rab move?

Answer 7

Actin with Dynein and Kinesin. Depending on which kind of Rab it is well determine what kind of motor it will bind to,

Question 8

CFTR

Answer 8

defect in CFTR opens ion channels in apical layer

Question 9

TIM and TOM

Answer 9

TOM: transports into outer membrane of mitochondria (proteins that present to TOM are positive)

TIM: transports stuff into inner membrane of mitochondria

Question 10

SAM

Answer 10

transports things out of mitochondria

Question 11

Transfer from Golgi into Lysosome to make enzymes

Answer 11

1. P-GlcNAc added to enzyme precursor
2. Mannose6Phosphate uncovered
3. M6P receptor bound
4. Receptor dependent transport
5. Receptor dissociates at high PH (early endosome) and phosphate removed
6. Rab takes receptor back

Question 12

cell transfer of LDL to cholesterol

Answer 12

1. LDL binds to receptor and forms vesicle
2. follows same steps as tranfer into lysosome.
3. lysosome releases free cholesterol