Secretory Pathways

Question 1

Where is the origin of the “anchor” for an rER protein?

Answer 1

It is on the protein being synthesized, not the ribosome. Ribosomes can float between ER and cytosol.

Question 2

How are cargo proteins put into a lipid vesicle?

Answer 2

Signal sequence on protein recruits SRP (signal recognition protein). Then the SRP hooks up with a translocon. A peptiase then cuts off the signal sequence and the rest of the protein is synthesized and put through the membrane.

Question 3

What is the amino acid sequence for N- linked glycosylation?

Answer 3

Asn-X-Ser/Thr

Question 4

What does Dolichol do?

Answer 4

It is a carrier lipid that helps facilitate n linked glycosylation,

Inhibited by statins

Question 5

COP II transports vesicles from…

Answer 5

ER–> Golgi

Question 6

COP I transports vesicles from…

Answer 6

Golgi–>ER

Question 7

What does clathrin do?

Answer 7

Facilitate endo/exocytosis. It binds to receptors that hold onto the target cargo.

Question 8

What is the role of dynamin?

Answer 8

Dynamin wraps around a budding vesicle and squeezes until the vesicle pops off.

Question 9

Which side of the Golgi faces the nucleus?

Answer 9

Cis

Question 10

What 4 letter amino acid sequence targets proteins to the ER?

Answer 10

KDEL