PMID- 11013349
OWN - NLM
STAT- MEDLINE
DCOM- 20001211
LR  - 20191025
IS  - 0952-5041 (Print)
IS  - 0952-5041 (Linking)
VI  - 25
IP  - 2
DP  - 2000 Oct
TI  - Functional characteristics of a novel murine estrogen receptor-beta isoform, 
      estrogen receptor-beta 2.
PG  - 229-42
AB  - We have isolated a highly expressed splice variant mRNA of murine estrogen 
      receptor-beta (ERbeta), mERbeta2, containing an in-frame 54 nucleotide insertion 
      between exons 5 and 6 of wild-type mERbeta1. The predicted ERbeta2 protein 
      contains 18 amino acids inserted in the ligand binding domain of mERbeta1. 
      Recombinant protein generated by in vitro transcription/translation showed that 
      mERbeta2 had markedly reduced ligand binding (K(D)=17.7+/-4.7 nM, mean+/-s.e.m., 
      n=3) compared with mERbeta1-bound (3)H-estradiol (K(D)=0.56+/- 0.19 nM, 
      mean+/-s.e.m., n=3). Both receptors bound similarly to palindromic estrogen 
      responsive elements (EREs) in vitro and in vivo, and similarly bent DNA. 
      Transcriptional activity was assessed using transient transfection analysis into 
      a homologous murine cell line, NIH 3T3 cells. mERbeta1 transactivated ERE-tk-CAT 
      reporter genes similarly to mERalpha, whereas mERbeta2 had little activity except 
      at high ligand concentrations. However, under conditions in which mERbeta2 is 
      unlikely to be ligand saturated, co-transfected mERbeta2 inhibited activity of 
      mERalpha and possibly mERbeta1 on ERE-tk-CAT genes. Using a 'novel raloxifene 
      responsive' gene reporter system (TGF-beta3-CAT), we found the ability of 
      estradiol and LY117018 to activate both mERalpha and mERbeta1 on this promoter 
      was identical, and mERbeta2 activity in the presence of either estradiol or 
      LY117018 was only slightly less than that observed with either mERbeta1 or 
      mERalpha. Both mERbeta1 and mERbeta2 when liganded with LY117018 inhibited 
      transcription at a classical ERE-regulated promoter under these transfection 
      conditions, which was in marked contrast to their stimulatory effect at the 
      transforming growth factor-beta3 promoter. These data suggest that responsiveness 
      of gene expression to a relatively highly expressed variant murine ERbeta 
      isoform, mERbeta2, is both ligand and promoter specific. Determination of the 
      relative level of expression of mERbeta1 mRNA and mERbeta2 mRNA in mouse tissues 
      indicated predominance of mERbeta2 mRNA in some but not all tissues. These data 
      suggest that the mERbeta2 may have some tissue-specific and promoter-specific 
      modulatory effects.
FAU - Lu, B
AU  - Lu B
AD  - Department of Biochemistry and Molecular Biology, University of Manitoba, 770 
      Bannatyne Avenue, Winnipeg, Manitoba, R3E 0W3, Canada.
FAU - Leygue, E
AU  - Leygue E
FAU - Dotzlaw, H
AU  - Dotzlaw H
FAU - Murphy, L J
AU  - Murphy LJ
FAU - Murphy, L C
AU  - Murphy LC
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - England
TA  - J Mol Endocrinol
JT  - Journal of molecular endocrinology
JID - 8902617
RN  - 0 (DNA Primers)
RN  - 0 (Estrogen Receptor beta)
RN  - 0 (Ligands)
RN  - 0 (Protein Isoforms)
RN  - 0 (RNA, Messenger)
RN  - 0 (Receptors, Estrogen)
RN  - 0 (Recombinant Proteins)
RN  - 4F86W47BR6 (Raloxifene Hydrochloride)
RN  - 4TI98Z838E (Estradiol)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - 3T3 Cells
MH  - Animals
MH  - Base Sequence
MH  - DNA/genetics/metabolism
MH  - DNA Primers/genetics
MH  - Estradiol/metabolism
MH  - Estrogen Receptor beta
MH  - Female
MH  - In Vitro Techniques
MH  - Kinetics
MH  - Ligands
MH  - Mice
MH  - Promoter Regions, Genetic/drug effects
MH  - Protein Isoforms/genetics/metabolism
MH  - RNA, Messenger/genetics/metabolism
MH  - Raloxifene Hydrochloride/pharmacology
MH  - Receptors, Estrogen/*genetics/*metabolism
MH  - Recombinant Proteins/genetics/metabolism
MH  - Tissue Distribution
MH  - Transcription, Genetic
EDAT- 2000/10/03 11:00
MHDA- 2001/02/28 10:01
CRDT- 2000/10/03 11:00
PHST- 2000/10/03 11:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2000/10/03 11:00 [entrez]
AID - JME00894 [pii]
AID - 10.1677/jme.0.0250229 [doi]
PST - ppublish
SO  - J Mol Endocrinol. 2000 Oct;25(2):229-42. doi: 10.1677/jme.0.0250229.