In this paper we describe a complete deletional analysis of hypersensitive site three (HS3) of the human beta-globin Locus Control Region (LCR). The previously defined core fragment consists of 6 footprinted regions, with multiple binding sites for the erythroid-specific factor GATA-1 and G-rich motifs that can interact with ubiquitous factors such as Sp1 and TEF-2. We show in this paper that the 5' half of this fragment is the most important for activity in murine erythroleukemia (MEL) cells. A fragment containing footprints 1-4 can stimulate transcription of a linked human beta-globin gene to levels of about 40% of that obtained with footprints 1-6. Constructs containing either footprints 1-3 or 3-6 cannot be distinguished from the beta-globin gene alone. We further show that binding sites for the erythroid-specific factor NF-E2 can co-operatively interact with parts of the HS3 core fragment, and that HS3 requires elements upstream from -103 in the human beta-globin promoter for full activity. The importance of these results is discussed in the context of the regulation of the genes in the human beta-globin cluster.

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BBA - Gene Structure and Expression
Erasmus MC: University Medical Center Rotterdam

Pruzina, S., Antoniou, M., Hurst, J., Grosveld, F., & Philipsen, S. (1994). Transcriptional Activation by hypersensitive site three of the human β-globin Locus Control Region in murine erythroleukemia cells. BBA - Gene Structure and Expression, 1219(2), 351–360. doi:10.1016/0167-4781(94)90059-0