Detection and characterization of the protein encoded by the chicken c-rel protooncogene.

We have identified the protein encoded by chicken c-rel, the cellular homolog of the v-rel oncogene carried by reticuloendotheliosis virus. The protein has been detected in two avian lymphoid cell lines and in chick embryo fibroblasts. It has a molecular weight of 68,000, suggesting that the viral gene (which encodes a protein of 59,000 molecular weight) is a truncated form of its cellular homolog. The c-rel protein is found in the soluble cytoplasmic fraction of chicken lymphoid cells and is not associated in any stable way with other cellular proteins. Unlike the viral protein, p68c-rel is not detectably phosphorylated.