A conserved tissue-specific structure at a human T-cell receptor beta-chain core promoter.
AUTOR(ES)
Halle, J P
RESUMO
The T-cell receptor (TCR) beta-chain promoters have been characterized as nonstructured basal promoters that carry a single conserved ubiquitous cyclic AMP-responsive element. Our investigation of the human TCR beta gene uncovers a surprisingly complex and tissue-specific structure at the TCR Vbeta 8.1 promoter. The core of the promoter (positions -42 to +11) is recognized by the lymphoid cell-specific transcription factors Ets-1, LEF1, and AML1 as well as by CREB/ATF-1, as is demonstrated in gel shift and footprinting experiments. With the exception of LEF1, these factors activate transcription in T cells. Binding sites at the core region show little conservation with consensus sites. Nonetheless, CREB, Ets-1, and AML1 bind and activate cooperatively and very efficiently through the nonconsensus binding sites at the core promoter region. Moderate ubiquitous activation is further induced by CREB/ATF and Sp1 factors through proximal upstream elements. The tissue-specific core promoter structure is apparently conserved in other T-cell-specifically expressed genes such as the CD4 gene. Our observations suggest that both the enhancer and the promoter have a complex tissue-specific structure whose functional interplay potentiates T-cell-specific transcription.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=232275Documentos Relacionados
- A conserved sequence in the T-cell receptor beta-chain promoter region.
- Rearrangement of T-cell receptor beta-chain genes during T-cell development.
- Diversity and structure of human T-cell receptor beta-chain variable region genes.
- Rearrangement and transcription of a T-cell receptor beta-chain gene in different T-cell subsets.
- Sequence and evolution of the human T-cell antigen receptor beta-chain genes.