title: Molecular cloning of the PRCII sarcoma viral genome and the chicken proto-oncogene c-fps.
abstract: The class II avian sarcoma viruses comprise PRCII, PRCIIp, PRCIV, URI, 16L, and Fujinami. The members of this class are all replication-defective viruses containing various amounts of a transforming sequence called v-fps. PRCII contains the smallest amount of fps-specific sequences, transforms fibroblasts in tissue culture, but is only weakly tumorigenic. As a first step in understanding variations in pathogenicity among the class II avian sarcoma viruses and the mechanism by which the oncogene of these viruses was transduced from a single cellular locus, we have molecularly cloned the viral genome of PRCII, its related helper PRCII-AV, and the chicken proto-oncogene (c-fps) from which v-fps derived. The fps-specific region within the cloned PRCII genome was shown to be 0.8-1.0 kb smaller than that of the Fujinami fps-specific region, in agreement with previous studies. Transfection of the cloned DNAs into primary chicken cells demonstrated that both clones (PRCII and PRCII-AV) are biologically active. The cloned PRCII genome is helper dependent and produces a gag-fusion phosphoprotein (P105) which is phosphorylated on a tyrosine residue. The cloned PRCII-AV genome produces infectious virus and can function as a helper for the cloned PRCII genome in transfection assays. Three overlapping recombinant lambda clones homologous to v-fps from a chicken genomic library have been isolated. One of these, lambda-c-fps(2), contains all of the cellular sequences homologous to v-fps. In the aggregate, the three molecular clones may represent the entirety of c-fps.
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002460:Cell Line; D002478:Cells, Cultured; D002642:Chick Embryo; D003001:Cloning, Molecular; D003370:Coturnix; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000302:isolation & purification; D005347:Fibroblasts; D005814:Genes, Viral; D008970:Molecular Weight; D011519:Proto-Oncogenes
chemical_list: D004279:DNA, Viral; D004262:DNA Restriction Enzymes