Expression of a typical animal gene is likely to be governed by several distinct enhancer elements that can be located in 5′ and 3′ genomic regions, as well as within intronic intervals [ 8].
By intersecting regulatory data from the ENCODE project, we found a functional SNP, rs4686484 (P = 3.12 × 10−49), that maps to several B-cell enhancer elements and a highly conserved region.
Whereas RIP140 recruitment was detected on distal enhancer elements of several genes, e.g. Stat5a, Myc, Lifr and Greb1, it was absent from several other proximal ERα binding sites, e.g. Cav1 and Vegfa, as well as enhancer regions for Areg, Pgr and Gata3 (Fig. 7F).
Several so-called pre-mRNA processing enhancer elements (PPE) located upstream of the core poly(A) sequences have been described for many viral and mammalian non-spliced genes (Huang and Carmichael, 1997; Conrad and Steitz, 2005; Guang and Mertz, 2005).
Several studies have identified functional variants involving enhancer elements and altered transcription factor binding.
In cultured cell lines, several amino acid-responsive genes such as ASNS (Asparagine synthetase) [6], [7], [8] and CHOP (C/EBP homologous protein) [9], [10], [11] have been reported to contain AAREs (Amino Acid Response Elements) that mediate the enhanced transcription and function as enhancer elements [10].
However, sequencing of the promoter and the enhancer elements of the PSA gene reveals several point mutations.
The HIV 5′ long-terminal repeat (LTR) that contains promoter and enhancer elements and has binding sites for several transcription factors is arranged in two nucleosomes, nuc-0 and nuc-1.
Several lines of evidence support the conclusion that these binding sites demarcate enhancer elements in human colon cancer cells.
