Newcastle disease virus (NDV), an avian paramyxovirus, initiates infection with attachment of the viral hemagglutinin-neuraminidase (HN) protein to sialic acid-containing receptors, followed by fusion of viral and cell membranes, which is mediated by the fusion (F) protein. Like all class 1 viral fusion proteins, the paramyxovirus F protein is thought to undergo dramatic conformational changes ...

The endoplasmic reticulum (ER) resident protein, ER60, is a member of the protein disulfide-isomerase family and contains two copies of the internal thioredoxin motif, CGHC. Previously, ER60 was identified as a cysteine protease and named ER-60 protease (Urade, R., Nasu, M., Moriyama, T., Wada, K., and Kito, M. (1992) J. Biol. Chem. 267, 15152-15159; Urade, R., and Kito, M. (1992) FEBS Lett. 31...

The relationship between protein synthesis, folding, and disulfide formation within the endoplasmic reticulum (ER) is poorly understood. Previous studies have suggested that pre-existing disulfide links are absolutely required to allow protein folding and, conversely, that protein folding occurs prior to disulfide formation. To address the question of what happens first within the ER, that is, ...