title: Sites of synthesis of viral proteins in avian sarcoma virus-infected chicken cells.
abstract: We determined the sites of synthesis of avian sarcoma virus-specific proteins in infected chicken cells by immunoprecipitation of the products synthesized in vitro by free and membrane-bound polyribosomes; 85% of Pr76, the precursor of the viral internal structural proteins (group-specific antigens), was synthesized on free polyribosomes, and 15% was synthesized on membrane-bound polyribosomes. Pr92, the lycosylated precursor of the viral glycoproteins (gp85 and gp35), was synthesized exclusively on membrane-bound polyribomes, which is consistent with its role as a membrane protein. When we investigated the site of synthesis of pp60src, the product of the avian sarcoma virus src gene, we found that 90% was synthesized on free polyribosomes, whereas 10% was detected on membrane-bound polyribosomes. The implications of these results with respect to the subcellular location of pp60src are discussed.
mesh_terms: D001355:Alpharetrovirus / Q000378:metabolism*; D000818:Animals; D001354:Avian Leukosis Virus / Q000378:metabolism*; D002460:Cell Line; D002472:Cell Transformation, Viral; D002642:Chick Embryo; D005347:Fibroblasts; D006023:Glycoproteins / Q000096:biosynthesis; D011132:Polyribosomes / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis; D014764:Viral Proteins / Q000096:biosynthesis*
chemical_list: D006023:Glycoproteins; D011498:Protein Precursors; D014764:Viral Proteins