Linked Life Data

16767802

Source:http://linkedlifedata.com/resource/pubmed/id/16767802

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2006-6-9
pubmed:abstractText
Estrogenic regulation of gene expression is mediated by the binding of the hormone to its receptors (ERalpha and ERbeta) followed by their binding to estrogen response element (ERE). Previous studies showed that natural polyamines -- putrescine, spermidine, and spermine -- facilitated ERalpha.ERE recognition. We determined the effects of natural and synthetic polyamines on the bending of a 27-mer oligonucleotide (ODN) harboring the ERE (ERE-ODN), using fluorescence resonance energy transfer (FRET) technique. Complementary strands of the ERE-ODN were labeled with fluorescein and tetramethylrhodamine, as donor and acceptor, respectively. The ERE-ODN was intrinsically bent with an end-to-end distance of 76 +/- 2 Angstrom, compared to a theoretical value of 98 Angstrom. The end-to-end distance of the ERE-ODN was reduced to 64 Angstrom in the presence of 250 microM spermine. A control ODN with scrambled sequence did not show intrinsic bending or spermine-induced bending. Alkyl substitution at the pendant amino groups reduced the ability of spermine to bend the ERE-ODN. Both ERalpha and ERbeta decreased the end-to-end distance of the ERE-ODN, although ERalpha was more efficient than ERbeta in inducing ERE bending. Spermine-induced bending of the ERE-ODN was significantly increased by ERalpha. Fluorescence anisotropy measurement showed that the equilibrium association constant of ERalpha-ERE binding increased by 12-fold in the presence of 250 microM spermine compared to control. The free energy change (Delta G) of ERalpha.ERE complex formation was -13.1 kcal/mol at 22 degrees C in the presence of spermine. Our results suggest that polyamine-induced bending of the ERE might be a mechanism for enhancing ERalpha-ERE binding affinity and thereby fine-tuning the transcriptional response of estrogen-responsive genes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1357-2725
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1191-1206
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Bending of the estrogen response element by polyamines and estrogen receptors alpha and beta: a fluorescence resonance energy transfer study.
pubmed:affiliation
Department of Medicine, University of Medicine and Dentistry of New Jersey--Robert Wood Johnson Medical School, New Brunswick, NJ 08903, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural