Identification of proteins within the nuclear factor-kappa B transcriptional complex including estrogen receptor-alpha.
OBJECTIVE
The objective of the study was to determine whether cross-talk occurs between estrogen receptors (ERs) and nuclear factor-kappa-B (NF-kappaB), to assess the functional consequences of such an ER/NF-kappaB interaction, and to identify other unknown regulatory proteins that may participate in the NF-kappaB transcriptional complex.


METHODS
Electromobility gel shifts, reporter gene assays, and mass spectrometry were used to identify proteins interacting with the NF-kappaB deoxyribonucleic acid (DNA) response element.


RESULTS
ER and the p65 subunit of NF-kappaB colocalized on DNA. This interaction was inhibitory for ER transcriptional activity. Sequencing of proteins bound to the NF-kappaB/DNA complex identified DNA-modifying enzymes, scaffolding proteins, chaperones, and elements of the nuclear matrix.


CONCLUSIONS
These studies have identified an inhibitory interaction between estrogen receptors and the p65 subunit of NF-kappaB with implications for estrogen action in pregnancy and cancer. New accessory proteins have also been identified that bind to protein complexes on the NF-kappaB DNA response element.
Feldman
Irv
I
Department of Obstetrics and Gynecology, University of Colorado Health Sciences Center, Denver, CO, USA.
Feldman
Gerald M
GM
Mobarak
Charlotte
C
Dunkelberg
Jeffrey C
JC
Leslie
Kimberly K
KK
D002478:Cells, Cultured; D024202:Electrophoretic Mobility Shift Assay; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011336:Probability; D011485:Protein Binding; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D015398:Signal Transduction; D015533:Transcriptional Activation; D014327:Trophoblasts / Q000166:cytology
D047628:Estrogen Receptor alpha; D016328:NF-kappa B