Comparative biochemical properties of p21 ras molecules coded for by viral and cellular ras genes.

摘要: In earlier studies, we molecularly cloned a normal cellular gene, c-rasH-1, homologous to the v-ras oncogene of Harvey murine sarcoma virus (v-rasH). By ligating type c retroviral promotor could transform NIH 3T3 cells with c-rasH-1 gene. The transformed contained high levels p21 protein coded for by current have purified extensively both v-rasH and c-rasH compared in vivo vitro biochemical properties these molecules. proteins shared certain properties: each was synthesized as precursor which subsequently became bound inner surface plasma membrane; associated guanine nucleotide-binding activity, property copurified molecules on high-pressure liquid chromatography molecular sizing column. some other properties, differed. vivo, approximately 20 30% were form phosphothreonine-containing pp21 molecules, whereas only minute fraction phosphate, this phosphate found serine residue. an authentic phosphothreonine peptide be autophosphorylation reaction gamma GTP transferred p21. No autophosphorylating activity vitro. results indicate major qualitative difference between c-rasH-1. mouse-derived oncogenic virus, BALB resembled that it nucleotides but did not label appreciably 32Pi. forms members ras gene family compared, is common all known family.