Abstract
Tissue specific regulation of the chicken lysozyme locus is achieved by a combination of positive and negative cis-regulatory elements. Here we describe the molecular characterization of a newly discovered enhancer element located −3.9 kb upstream of the transcription start. The −3.9 kb enhancer is activated early in macrophage differentiation, as indicated by chromatin reorganization in macrophage precursor cells. Interestingly, enhancer activation leads to nucleosome phasing. Tissue specificity of expression is achieved by a combination of 5′-sequences with ubiquitous enhancer activity and 3′-flanking sequences. The 5′-half contains binding sites for members of the nuclear factor I transcription family and a yet unknown protein. We could show by in vivo footprinting that the ubiquitously expressed factors occupy their binding sites only in lysozyme expressing cells. We conclude that a specific chromatin architecture may be responsible for the differential activity of the enhancer.
Original language | English |
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Pages (from-to) | 63-77 |
Journal | Gene |
Volume | 236 |
Issue number | 1 |
DOIs | |
Publication status | Published - 5 Aug 1999 |
Keywords
- Chromatin domain
- Macrophage specific gene expression
- Nuclear factor I
- Nucleosome phasing
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)