Characterization of the human [beta]-globin downstream promoter region

• Published in: Nucleic acids research 2003-02, Vol.31 (4), p.1292
• Main Authors: Leach, Kelly M, Vieira, Karen F, Sung-Hae Lee Kang, Aslanian, Ara, Teichmann, Martin, Roeder, Robert G, Bungert, Jorg
• Format: Article
• Language: English
• ISSN: 0305-1048; 1362-4962

The human [beta]-globin gene is abundantly expressed specifically in adult erythroid cells. Stage-specific transcription is regulated principally by promoter proximal cis-regulatory elements. The basal promoter contains a non-canonical TATA-like motif as well as an initiator element. These two elements have been shown to interact with the TFII-D complex. Here we show that in addition to the TATA and initiator elements, conserved E-box motifs are located in the [beta]-globin downstream promoter. One of the E-box motifs overlaps the initiator and this composite element interacts with USF1 and TFII-I in vitro. Another E-box, located 60 bp 3' to the transcription initiation site, interacts with USF1 and USF2. Mutations of either the initiator or the downstream E-box impair transcription of the [beta]-globin gene in vitro. Mutations of a putative NF-E2-binding site in the downstream promoter region do not affect transcription in vitro. USF1, USF2, TFII-I and p45 can be crosslinked to a [beta]-globin promoter fragment in MEL cells in vivo, whereas only TFII-I and USF2 crosslink to the [beta]-globin gene in K562 cells. The summary data demonstrate that in addition to the well-characterized interactions of the TFII-D complex with the basal promoter, E-box motifs contribute to the efficient formation of transcription complexes on the adult [beta]-globin gene.