The 3' untranslated region of the chicken c-src protooncogene modulates gene expression.

Tight regulation of the Src tyrosine kinase activity is essential for a variety of cellular processes, namely transitions of the cell cycle. The peaks of Src activity are dependent on its posttranslational modifications as well as on the regulation of gene expression. The 3'UTRs of mRNAs are often crucial for rapid changes of the protein level. The chicken c-src 3'UTR effects on gene expression have been explored. The c-src 3'UTR decreased the in vivo tumorigenic potential of the src-activated mutants in chickens. This corresponds with the finding that the c-src 3'UTR reduced the Src protein and src mRNA levels and luciferase activity in vitro. Our results suggest that the chicken c-src 3'UTR plays a role in the negative control of gene expression, either transcriptionally or posttranscriptionally.