What is the most likely fate of a protein with an Nterminal

What is the most likely fate of a protein with an N-terminal ER sorting signal and a hydrophobic domain of 22 amino acids?

a. The protein stays in the cytosol

b. The protein is transported to the mitochondrium because many transmembrane proteins function in ATP synthesis

c. The protein is translocated all the way into the ER lumen

d. The hydrophobic transmembrane domain is recognized once it is in the translocation channel and released sideways into the membrane

e. The hydrophobic domain is cleaved off by signal peptidase

Solution

The correct answer is : c.The protein is translocated all the way into the ER.

Reason: Proteins with N terminal ER sorting signal and hydrphobic domain of 22 aminoacids is likely to be translocated to the lumen of ER.