25.1Introduction Sorting signal is a motif in a protein (either a short sequence of amino acids or a covalent modification) that is required for it to be incorporated into vesicles that carry it to a specific destination 消当Sorting signal is a motif in a protein (either a short sequence of amino acids or a covalent modification) that is required for it to be incorporated into vesicles that carry it to a specific destination. 25.1 Introduction