Synthetic human beta-globin 5'HS2 constructs function as locus control regions only in multicopy transgene concatamers

EMBO J. 1993 Jan;12(1):127-34.

Abstract

Transgenes linked to the beta-globin locus control region (LCR) are transcribed in a copy-dependent manner that is independent of the integration site. It has previously been shown that the LCR 5'HS2 region does not require its NF-E2 dimer binding site for LCR activity. In this paper we analyse synthetic 5'HS2 core constructs containing point mutations in the other factor binding sites 3' of the NF-E2 dimer site. The results show that 5'HS2 core is a partially active LCR that functions in a concatamer of at least two copies but not when present as a single copy in transgenic mice and that no single binding site within 5'HS2 is required for position-independent expression. In addition, the H-BP factor is identical to upstream stimulatory factor (USF) and full enhancement levels by 5'HS2 core in MEL cells require a combination of all the factor binding sites. We suggest that 5'HS2 cores in a concatamer interact with each other to establish an area of open chromatin and that this process may be the basis of LCR function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • DNA / genetics
  • DNA / isolation & purification
  • DNA-Binding Proteins / genetics
  • Erythroid-Specific DNA-Binding Factors
  • Fetus
  • Genes, Regulator*
  • Genes, Synthetic*
  • Globins / genetics*
  • Humans
  • Introns
  • Liver / physiology
  • Mice
  • Mice, Transgenic
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • NF-E2 Transcription Factor
  • NF-E2 Transcription Factor, p45 Subunit
  • Restriction Mapping
  • Transcription Factors / genetics
  • Transfection
  • Zinc Fingers / genetics

Substances

  • DNA-Binding Proteins
  • Erythroid-Specific DNA-Binding Factors
  • NF-E2 Transcription Factor
  • NF-E2 Transcription Factor, p45 Subunit
  • NFE2 protein, human
  • Nfe2 protein, mouse
  • Transcription Factors
  • Globins
  • DNA