A short sequence in the COOH-terminus makes an adenovirus membrane glycoprotein a resident of the endoplasmic reticulum.
The E19 protein of adenoviruses is a transmembrane protein that abrogates the intracellular transport of class I antigens by forming complexes with them in the ER. We show here that the E19 protein is retained in the ER even in the absence of class I antigens. To define the region conferring residency in the ER, we examined two mutant forms of the viral protein. A 5 amino acid extension of the 15-membered cytoplasmic tail of the protein reduces its interaction with class I antigens but does not change its intracellular distribution. Shortening the tail to 7 amino acids also diminishes the affinity for class I antigens; however, this mutant E19 protein becomes transported to the cell surface. Thus, we concluded that a small stretch of amino acids exposed on the cytoplasmic side of the ER membrane is responsible for the retention of the E19 protein in the ER.
D017456:Adenovirus Early Proteins; D000260:Adenoviruses, Human / Q000235:genetics; D000957:Antigens, Viral, Tumor / Q000032:analysis; D004721:Endoplasmic Reticulum / Q000032:analysis / Q000648:ultrastructure*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells / Q000166:cytology; D006801:Humans; D009154:Mutation; D009856:Oncogene Proteins, Viral / Q000032:analysis / Q000235:genetics* / Q000378:metabolism
D017456:Adenovirus Early Proteins; D000957:Antigens, Viral, Tumor; D009856:Oncogene Proteins, Viral