Chromatin profiling across the human tumour necrosis factor gene locus reveals a complex, cell type-specific landscape with novel regulatory elements

Nucleic Acids Res. 2008 Sep;36(15):4845-62. doi: 10.1093/nar/gkn444. Epub 2008 Jul 24.

Abstract

The TNF locus on chromosome 6p21 encodes a family of proteins with key roles in the immune response whose dysregulation leads to severe disease. Transcriptional regulation is important, with cell type and stimulus-specific enhancer complexes involving the proximal TNF promoter. We show how quantitative chromatin profiling across a 34 kb region spanning the TNF locus has allowed us to identify a number of novel DNase hypersensitive sites and characterize more distant regulatory elements. We demonstrate DNase hypersensitive sites corresponding to the lymphotoxin alpha (LTA) and tumour necrosis factor (TNF) promoter regions, a CpG island in exon 4 of lymphotoxin beta (LTB), the 3' end of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-like 1 (NFKBIL1) and 3.4 kb upstream of LTA. These sites co-localize to highly conserved DNA sequences and show evidence of cell type specificity when lymphoblastoid, Jurkat, U937, HeLa and HEK293T cell lines are analysed using Southern blotting. For Jurkat T cells, we define histone modifications across the locus. Peaks of acetylated histone H3 and H4, together with tri-methyl K4 of histone H3, correspond to hypersensitive sites, notably in exon 4 of LTB. We provide evidence of a functional role for an intergenic DNase I hypersensitive site distal to LTA in Jurkat cells based on reporter gene analysis, with evidence of recruitment of upstream stimulatory factors (USF) transcription factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Blotting, Southern
  • Cell Line
  • Chromatin / chemistry*
  • Conserved Sequence
  • DNA Footprinting
  • Deoxyribonuclease I
  • Enhancer Elements, Genetic
  • Histones / metabolism
  • Humans
  • Jurkat Cells
  • Lymphotoxin-alpha / genetics
  • Phylogeny
  • Regulatory Elements, Transcriptional*
  • Tumor Necrosis Factors / genetics*

Substances

  • Chromatin
  • Histones
  • Lymphotoxin-alpha
  • Tumor Necrosis Factors
  • Deoxyribonuclease I