12 - Using yeast to understand cell trafficking pathways

Question 1

What are the two membrane trafficking pathways?

Answer 1

Secretory/exocytic (biosynthetic) pathway - ER to the golgi to PM/ endosome/lysosome

endocytic pathway (recycling or degradative) - cell surface to endosome to Golgi/ER/lysosome

Question 2

Are mitochondria part of the secretory pathway?

Answer 2

No

Question 3

Where are proteins modified + Processed?

Answer 3

Modified by oligosaccharide addition in the ER
Processed in the golgi

Question 4

what types of glycosylation occur in proteins?

Answer 4

n- and o-

Question 5

What are the steps of glycosylation?

Answer 5

ER lumen:
addition of pre-formed oligosaccharide to an asparagine aa

Addition + processing of oligosaccharides during transit

In golgi:
oligosaccharide group is trimmed
later in golgi - further sugars added + more branches