Estrogen Receptor Accessory Factors in Breast Cancer Cells.
Abstract
The goal of this investigation is to test the hypothesis that estrogen agonists and antagonists promote differential transcriptional activity of the estrogen receptor (ER) by altering accessory protein interactions. We have shown that one or more ER-associated proteins (hsp70, PDI, p48, p45) may be required for maximal interaction of ER with specific DNA sites (EREs) in responsive genes and that the same proteins contribute to the magnitude of DNA distortion without altering the direction of the ER-induced bend of ERE-containing DNA fragments, which is toward the major groove of the DNA helix. We have also used the ligand binding domain of the ER (aa 282-595), expressed in bacteria as a GST-fusion protein (GST-LBD), to capture proteins from mammalian cell extracts that associate with the ER. One protein retained by this technique is a kinase that phosphorylates ER only in the presence of estrogen agonists. Phosphoamino acid analysis and manual sequencing of tryptic peptides have identified the site of phosphorylation as serine 559, a putative casein kinase II phosphorylation site.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1997
- Accession Number
- ADA337563
Entities
People
- Geoffrey L Greene
Organizations
- University of Chicago