Andrew Ziemiecki

Simultaneous injection of newborn rabbits with the Schmidt-Ruppin and prague strains of Rous sarcoma virus induces antibodies which recognize the pp60src of both strains.

Simultaneous injection of newborn rabbits with the Schmidt-Ruppin and Prague strains of Rous sarcoma virus regularly induces antibodies which not only recognize the pp60src of both strains but also give positive kinase reaction with extracts of cells infected with either strain.

Oligosaccharide modifications and the site of processing of gPr92env, the precursor for the viral glycoproteins of rous sarcoma virus

Abstract We have studied the processing of the RSV glycoprotein precursor gPr92 env to mature viral disulfide-linked gp85 and gp35 (VGP). The first aspect concerned the steps involved in the processing event. We could show that, in addition to proteolytic cleavage, the processing of gPr92 env involves the conversion of oligosaccharides from the high-mannose type found in gPr92e env to the complex, sialidated type found in VGP. Concerning the site of processing, we failed to demonstrate gPr92 env in newly released virions but could find a small amount of gPr92 env on the cell surface. It is thus conceivable, but unlikely, that processing is taking place at the cell surface. gp85 and gp35 could be detected in low, somewhat variable amounts in cell lysates and we have shown that most of this is within the cell and not at the cell surface. We favor the possibility that processing of gPr92 env is occurring at the usual sites of glycosylation, namely in the rough ER and Golgi complex, and that the surface gPr92 env is a “dead-end” product which does not become incorporated into virus.