A myristylated form of the sea oncoprotein can transform chicken embryo fibroblasts

The transforming gene product of the S13 avian erythroblastosis virus, v-sea, is a member of the growth factor receptor class of tyrosine kinases. In the virus genome, the sea sequences are fused in frame to the virus env gene, thereby generating an abnormally large envelope protein because of the presence of a cytoplasmic tyrosine kinase domain. To determine what role these envelope sequences play in v-sea transformation, we generated a myristylated form of v-sea which contains no envelope sequences. In this report, we show that this myristylated sea-encoded protein retained the ability to transform chicken embryo fibroblasts, indicating that envelope sequences are not essential for transformation by the v-sea tyrosine kinase.