The role of the C-terminal extension (CTE) of the estrogen receptor alpha and beta DNA binding domain in DNA binding and interaction with HMGB.
HMGB-1/-2 are coregulatory proteins that facilitate the DNA binding and transcriptional activity of steroid receptor members of the nuclear receptor family of transcription factors. We investigated the influence and mechanism of action of HMGB-1/-2 (formerly known as HMG-1/-2) on estrogen receptor alpha (ERalpha) and ERbeta. Both ER subtypes were responsive to HMGB-1/-2 with respect to enhancement of receptor DNA binding affinity and transcriptional activity in cells. Responsiveness to HMGB-1/-2 was dependent on the C-terminal extension (CTE) region of the ER DNA binding domain (DBD) and correlated with a direct protein interaction between HMGB-1/-2 and the CTE. Thus the previously reported higher DNA binding affinity and transcription activity of ERalpha as compared with ERbeta is not due to a lack of ERbeta interaction with HMGB-1/-2. Using chimeric receptor DBDs, the higher intrinsic DNA binding affinity of ERalpha than ERbeta was shown to be due to a unique property of the ERalpha CTE, independent of HMGB-1/-2. The CTE of both ER subtypes was also shown to be required for interaction with ERE half-sites. These studies reveal the importance of the CTE and HMGB-1/-2 for ERalpha and ERbeta interaction with their cognate target DNAs.
Melvin
Vida Senkus
VS
Molecular Biology Program, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
Harrell
Chuck
C
Adelman
James S
JS
Kraus
W Lee
WL
Churchill
Mair
M
Edwards
Dean P
DP
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005982:Glutathione Transferase / Q000378:metabolism; D024002:HMGB Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011960:Receptors, Estrogen / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014162:Transfection; D016335:Zinc Fingers
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D024002:HMGB Proteins; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D004247:DNA; D005982:Glutathione Transferase