Final answer:
Signal peptide patterns consist of N-terminal sequences that guide proteins to specific cellular compartments; after leading the protein to its destination, these sequences are cleaved off and removed.
Step-by-step explanation:
Signal peptide patterns (SPPs) comprise N-terminal sequences of amino acids that are responsible for directing the proteins to specific cellular compartments. The prompt fate of SPPs is typically their cleavage and removal after they have guided the proteins to their respective destinations. For example, in the process of protein synthesis, signal sequences direct a nascent polypeptide to the rough endoplasmic reticulum (RER) where a signal peptidase catalyzes the hydrolysis of the signal peptide.
These signal peptides can also direct proteins to other organelles such as mitochondria or chloroplasts. Once their role in targeting the protein is completed, these signal sequences, which can be found at either the amino or carboxyl end of the protein, are removed. This ensures the proper functioning of the proteins as they carry out their roles within the cell.