What would happen to a secreted protein (e.g. insulin) if you produced it from an mRNA missing the sequence encoding the signal peptide?
It would be properly secreted, though it might not fold correctly.
It would get translated in the cytoplasm and remain there.
It would get trapped in the ER.
It would get transported to the plasma membrane and become embedded there.
Answer- It would get translated in the cytoplasm and remain there.
Explanation-
Signal sequence drives targeting of nascent polypeptide from cytosol to endoplasmic reticulum which is entry point for secretory pathway. In this secretory pathway if signaling sequence is missing in secretory protein then nascent protein will not be transported to the membrane of endoplasmic reticulum through G- protein coupled receptors (GPCRs). So that secretory protein translated from mRNA missing signal sequence would be translated in the cytoplasm and remain there.
What would happen to a secreted protein (e.g. insulin) if you produced it from an mRNA...