Complex expression pattern of the CEF-4 cytokine in transformed and mitogenically stimulated cells.

The transformation of chicken embryo fibroblasts (CEF) by the Rous sarcoma virus leads to the constitutive expression of the cellular gene designated CEF-4. With specific antisera, we confirmed that transformed cells actively synthesize and secrete a 6 kDa polypeptide corresponding to the CEF-4 gene product. The expression of CEF-4 was investigated by Northern and immunoprecipitation analyses. Upon activation of pp60v-src in cells infected by a …