Question

Choose CORRECT answer(s): What would happen to the location of a newly synthesized single-pass transmembrane protein if the gene sequence that codes for its �ER signal sequence� was deleted? It would�

Question 15 options:

A	remain embedded in the plasma membrane
B	be exocytosed from the cell
C	be retained in the ER
D	be localized in the cytosol
E	become a multi-pass protein

Answer 1

In this context, the signal sequence of a protein is an important part of the protein that allows the delivery of the newly formed peptide to the Endoplasmic reticulum. The signal sequence codes for hydrophobic amino acids at the N-terminus of the protein. This signal peptide is then recognized by a complex called signal-recognition particle which will bind to the signal peptide and translocate it to the ER. A mutation that depletes this sequence will lead to the retention of the protein in the cytosol. So, the correct answer is be localized in the cytosol