title: The expression in eukaryotes of a tyrosine kinase which is reactive with pp60v-src antibodies.
abstract: All specimens of Eumetazoa and Parazoa, ranging from mammals, birds, teleosts, sharks, lampreys, amphioxus, insects, down to sponges showed the pp60c-src associated kinase activity, indicating that c-src, which is the cellular homologue of the oncogene v-src of Rous sarcoma virus (RSV) is probably present in all multicellular animals. Protozoa and plants did not show pp60c-src kinase activity. The degree of c-src expression depends on the taxonomic rank of the Eumetazoa tested, and is organ-specific with nervous tissues displaying the highest kinase activities. In the central nervous system of mammals and birds we found a high c-src expression, and in that of the lampreys, amphioxus, and insects the lowest. Unexpectedly, total extracts of sponges showed an amount of pp60c-src kinase activity similar to that of brain cell extracts of mammals and birds. These findings suggest that pp60c-src is a phylogenetic old protein that might have evolved together with the multicellular organisation of Metazoa, and that might be of importance in proliferation and differentiation of nontransformed cells.
mesh_terms: D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex; D002645:Chickens; D005399:Fishes; D007313:Insecta; D051379:Mice; D015688:Oncogene Protein pp60(v-src); D011161:Porifera; D011494:Protein Kinases / Q000235:genetics* / Q000276:immunology; D011505:Protein-Tyrosine Kinases; D011784:Quail; D051381:Rats; D013045:Species Specificity; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology
chemical_list: D000906:Antibodies; D000936:Antigen-Antibody Complex; D014764:Viral Proteins; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)