The First Step in the Post-Translational Processing of Secreted Proteins

question 4

Multiple Choice

The first step in the post-translational processing of secreted proteins in eukaryotes is:

• A)Proteolytic removal of the first two or three amino acid residues from the amino terminus by the signal recognition particle.
• B)Attachment of a mannose-rich oligopeptide to asparagine side chains.
• C)Attachment of mannose-6-phosphate to the protein.
• D)Proteolytic cleavage by signal peptidase.
• E)Formation of disulfide bonds.