Avian sarcoma virus UR2 encodes a transforming protein which is associated with a unique protein kinase activity.

摘要: UR2 is a newly characterized avian sarcoma virus whose genome contains unique sequence that not related to the sequences of other transforming genes thus far identified. This sequence, termed ros, fused part viral gag gene. The product gag-ros gene protein 68,000 daltons (P68) immunoprecipitable by antiserum against proteins. In vitro translation RNA and in vivo pulse-chase experiments showed P68 synthesized as large precursor it only encoded genome, suggesting involved cell transformation UR2. vivo, was phosphorylated at both serine tyrosine residues. Immunoprecipitates with anti-gag antisera had cyclic nucleotide-independent kinase activity P68, rabbit immunoglobulin G immune complex, alpha-casein. phosphorylation specific substrate one site, tryptic phosphopeptide vitro-labeled different from those Fujinami P140 Y73-P90. A comparison kinases UR2, Rous virus, Y73 revealed UR2-P68 distinct viruses several criteria. Our results suggest have same functional specificity cause essentially cellular alterations.