Although cohesin is absent from the transcription units of PcG-silenced genes, it binds many polycomb response elements (PREs) that initiate and mediate silencing (Misulovin et al. 2008).
An example for this competing endogenous RNA (ceRNA) is the transcribed PTENP1 pseudogene, which contains many microRNA response elements (MREs) also present in the tumor suppressor PTEN.
Nrf2 protects cells from environmental insults through transcriptional up-regulation of many antioxidant response element (ARE -bearing genes including, ARE -bearingencodingeneses, phase includingfying genes, and phase III transporter genes [3], [4], [5], [6].
Nuclear factor erythroid 2 related factor 1 (NRF1, also called NFE2L1) plays a critical role in regulating the expression of many antioxidant response element (ARE -dependent genes.
Nrf2, a redox sensitive transcription factor, is a master regulator of intracellular antioxidants and phase II detoxification enzymes by the transcriptional activation of many antioxidant response element (ARE -containing genes [ 9, 10].
The transcription factor nuclear factor (erythroid-2)–related factor 2 (Nrf2), which is a basic redox-sensitive bZIP transcription factor, was originally identified as a critical regulator of intracellular antioxidants and of phase II detoxification enzymes through the transcriptional upregulation of many antioxidant response element (ARE) -containing genes [ 7- 9].
Although many known such response elements are conserved in the mouse and human genomes, it is unclear to which extent transcriptional regulation by nuclear receptors has evolved specifically in primates.
More recently, an unbiased approach to determine CLOCK, BMAL, PER, and CRY binding sites in the whole genome of mouse liver by ChIP-Seq revealed that not only E-boxes, but also many nuclear receptor response elements (NREs) are at close proximity with the binding sites of these circadian clock regulators 23, 24.
Many receptors recognize DNA hormone response elements formed by direct repeats of RGKTCA motifs separated by 1 to 5 bp (DR1-DR5).
CREB can be activated by various kinases in response to electrical activity, neurotransmitters, hormones, and neurotrophins, thus promoting the expression of many genes that contain cAMP response elements (Finkbeiner et al., 1997; Hardingham & Bading, 1998).
