A second sequence element located 3' to the NF-kappa B-binding site regulates IL-2 receptor-alpha gene induction.

Transcriptional induction of the gene encoding the alpha-subunit of IL-2R has been shown to be mediated by a sequence element (GGGGAATCTCCC) that is homologous to the NF-kappa B-binding site of the kappa Ig gene enhancer. In this report we demonstrate that the induced transcription of this gene by mitogen and by the tax gene product of the type-I human T cell leukemia virus is dependent upon an additional sequence motif (GGGCGTAGC) located approximately 10 bp downstream of the previously identified site. This newly identified motif binds a factor that is present in extracts derived from different cell types and does not appear to be required for basal promoter activity. We conclude that proteins binding at both sites act coordinately, leading to maximal induction of the receptor gene.