The Golgi

Question 1

cisternae

Answer 1

stacks of compartments that make up the Golgi

Question 2

Golgi location

Answer 2

Microtubules localize the Golgi near the nucleus

Question 3

Golgi function

Answer 3

Modify and sort proteins

Question 4

Cisternal progression model

Answer 4

Cisternae form at the cis face, move through the Golgi, dissociate into vesicles

Question 5

Problems with cisternal progression model

Answer 5

• Vesicles seen budding and fusing simultaneously
• Golgi membrane proteins have long residence in the Golgi
• Different cisternae are biochemically distinct

Question 6

Stable compartments theory

Answer 6

The cisternae stack is fixed and vesicles transport proteins between cisternae

Question 7

Problems with stable compartment model

Answer 7

• Enzymes are not restricted to single compartments
• Many enzymes through the Golgi are larger than COPI vesicles
• COPI vesicles don’t necessarily only move forward

Question 8

Cisternal progenator model

Answer 8

Cisternae are stable compartments separated into different domains. Rab fuses parts of cisternae that allows cargo to move forward towards the TGN.

Question 9

Problems with cisternal progenitor model

Answer 9

• Megavesicles (fused cisternae) have not been observed

- Low specificity

Question 10

Rab proteins

Answer 10

When in the active state (GTP), recruits effector proteins that have different effects on the membrane including cargo and vesicle interactions