In proteins being made on rough ER, short spans of hydrophobic amino acids that form $\alpha$ helices
A) induce a conformational change in the translocon, allowing them to exit into the ER membrane.
B) are posttranslationally inserted into the ER membrane by BiP.
C) are ubiquitinated and transferred into the cytosol for proteasomal degradation.
D) cause premature termination of translation, leading to the unfolded protein response.

Question

Quizplus · Accepted Answer

The short spans of hydrophobic amino acids that form F1F1F1S1F1F1F10 helices induce a conformational change in the translocon, allowing them to exit into the ER membrane. This process is known as translocation, and it is an essential step in the formation of membrane proteins on the rough ER. B, C, and D are not correct because they do not accurately describe the mechanism by which membrane proteins are formed on the rough ER.

In Proteins Being Made on Rough ER, Short Spans of Hydrophobic