What protein binds directly to newly emerging polypeptide in order to bring it to the ER?
Asked By Zai Lee
- 19 Dec 2018 @ 09:09
Replied by Admin
Signal peptide binds directly to the newly emerging polypeptide in order to bring it to the ER.
Explanation: Signal peptide is a short peptide that is present at the N-terminus of newly synthesized proteins. Proteins are translocated into the lumen of the ER during translation only if they have an amino sequence, which is called as a signal peptide.
The signal peptide sequence attached to the membrane and later is cleaved off by signal peptidase. Proteins that do not have a signal peptide remains in the cytosol for translation as translation takes place in the cytosol. Proteins for the destination to endomembrane system are first destined to ER during translation.
The signal peptide that is emerged from ribosome will bind to the signal-recognition particle (SRP) and then it docks to the SRP-receptor. SRP dissociates and is then translocated through the channel into the ER lumen. The signal peptide then cleaved off and the protein is finally secreted out of the cell.
- 19 Dec 2018 @ 09:08