Regulation of estrogen receptor-mediated long range transcription via evolutionarily conserved distal response elements.
Nuclear signaling by estrogens rapidly induces the global recruitment of estrogen receptors (ERs) to thousands of highly specific locations in the genome. Here, we have examined whether ER binding sites that are located distal from the transcription start sites of estrogen target genes are functionally relevant. Similar to ER binding sites near the proximal promoter region, ER binding sites located at distal locations are occupied by ERs after estrogen stimulation. And, like proximal bound ERs, ERs occupied at distal sites can recruit coactivators and the RNA polymerase transcription machinery and mediate specific structural changes to chromatin. Furthermore, ERs occupied at the distal sites are capable of communicating with ERs bound at the promoter region, possibly via long range chromosome looping. In functional analysis, disruption of the response elements in the distal ER binding sites abrogated ER binding and significantly reduced transcriptional response. Finally, sequence comparison of the response elements at the distal sites suggests a high level of conservation across different species. Together, our data indicate that distal ER binding sites are bona fide transcriptional enhancers that are involved in long range chromosomal interaction, transcription complex formation, and distinct structural modifications of chromatin across large genomic spans.
Pan
You Fu
YF
Cancer Biology and Pharmacology, Genome Institute of Singapore, Agency for Science, Technology and Research, 60 Biopolis St., 02-01 Genome, Singapore 138672.
Wansa
K D Senali Abayratna
KD
Liu
Mei Hui
MH
Zhao
Bing
B
Hong
Shu Zhen
SZ
Tan
Peck Yean
PY
Lim
Kar Sian
KS
Bourque
Guillaume
G
Liu
Edison T
ET
Cheung
Edwin
E
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D002843:Chromatin / Q000737:chemistry; D004742:Enhancer Elements, Genetic; D004967:Estrogens / Q000378:metabolism; D019143:Evolution, Molecular; D016678:Genome; D006657:Histones / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011960:Receptors, Estrogen / Q000378:metabolism*; D020218:Response Elements; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D002843:Chromatin; D004967:Estrogens; D006657:Histones; D011960:Receptors, Estrogen