A Transcriptional Enhancer 3′ of C β2 in the T Cell Receptor β Locus

Run-on transcription experiments were used to demonstrate that transcription of T cell receptor beta chain V genes is activated by DNA rearrangement, in a manner similar to immunoglobulin genes. A transcriptional enhancer likely to be involved in this activation has been identified. A 25-kilobase region from J beta 1 to V beta 14 was tested for enhancer activity by transient transfections, and an enhancer was found 7.5 kilobases 3' of C beta 2. The beta enhancer has low activity relative to the simian virus 40 viral enhancer, does not display a preference for V beta promoters, has a T cell-specific activity, and binds two purified immunoglobulin heavy chain enhancer factors.