Deletions into an NH2-terminal hydrophobic domain result in secretion of rotavirus VP7, a resident endoplasmic reticulum membrane glycoprotein

the portions of the expressed products that are important in determining their plasma membrane localization. These membrane glycoproteins are characterized by a COOH-terminal hydrophobic membrane anchoring segment and a cytoplasmic tail. Disruption of the former has generally resulted in complete secretion of these molecules, which in their native state traverse most of the secretory pathway. Alterations of the COOH-terminal cytoplasmic tail had diverse effects. Some mutant proteins became blocked along the secretory pathway and others failed to traverse the pathway at all. The exact nature of the signal for targeting these proteins to the plasma membrane was not clear from these studies. Failure of these molecules to move along the exocytosis pathway may have been due to the alteration of a positive plasma membrane targeting signal or to denaturation of the protein product.