After removal of the terminal signal sequence in the lumen of the ER, additional signals are needed to direct the protein to its destination. These signals are of two kinds; what are they?
1) Some are sequences of amino acids that allow the protein's retention within the ER
2) Others are sugars, which are added in the Golgi Apparatus. The resulting glycoproteins end up either at the plasma membrane or in a lysosome (or plant vacuole), or are secreted, depending on which sugars are added