FIG. 5.

Flow diagram illustrating the occurrence of a heterogenous population of APN molecules expressed in Sf21 cells as shown in Fig. 4. Population A consists of molecules that have undergone transamidation at the COOH terminus and are transported to plasma membrane; these molecules lose the COOH-terminal His tag and are not visualized with anti-His antibodies. Population B consists of molecules that remain unprocessed and are retained in the endoplasmic reticulum (ER) with the His tag. These molecules are visualized with anti-His antibodies. Details are given in Discussion.