Isolation and characterization of multiple human genes homologous to the oncogenes of avian erythroblastosis virus.

Human DNA sequences complementary to the oncogenes v-erbA and v-erbB of avian erythroblastosis virus have been isolated from a genomic DNA library. Two clones, lambda he-A1 and lambda he-A2, were related to the erbA gene and one to the erbB gene (lambda he-B). The two erbA genes were only distantly related to each other as judged from hybridization analysis. Furthermore, human chromosomal DNA appears to contain one or two additional genes analogous to the lambda he-A2 sequence, whereas the mouse genome contained only two genes complementary to lambda he-A1 and lambda he-A2, respectively. Polyadenylated RNA species, 5.0 kb in size, were found in the human HeLa and the human hematopoietic K562 cell lines, suggesting that at least some of the erb-related genes are active and do not represent pseudogenes. Taken together, the data demonstrate that two distantly related classes of erbA genes exist in human and mouse DNA, and that multiple copies of genes belonging to one of these two classes exist in the human genome.