Histone acetylation precedes activation of many genes. However, the establishment and consequences of long-range acetylation patterns are poorly understood. To define molecular determinants of the developmentally dynamic histone acetylation pattern of the β-globin locus, we compared acetylation of the locus in MEL and CB3 erythroleukemia cells. CB3 cells lack the β-globin locus control region (LCR) binding protein p45/NF-E2. We found that p45/NF-E2 was required for histone hyperacetylation at adult β-globin promoters ∼50 kilobases downstream of the LCR, but not at the LCR. Surprisingly, RNA polymerase II associated with the LCR in a p45/NF-E2-independent manner, while its recruitment to the promoter required p45/NF-E2. We propose that polymerase accesses the LCR and p45/NF-E2 induces long-range transfer of polymerase to the promoter, resulting in transcriptional activation.
Johnson, K. D., Christensen, H. M., Zhao, B., & Bresnick, E. H. (2001). Distinct mechanisms control RNA polymerase II recruitment to a tissue-specific locus control region and a downstream promoter. Molecular Cell, 8(2), 465–471. https://doi.org/10.1016/S1097-2765(01)00309-4