PMID- 2355731
OWN - NLM
STAT- MEDLINE
DCOM- 19900720
LR  - 20190817
IS  - 0022-4731 (Print)
IS  - 0022-4731 (Linking)
VI  - 35
IP  - 5
DP  - 1990 Apr
TI  - Identification of unoccupied but transformed nuclear estrogen receptor in 
      cultured mouse Leydig cell.
PG  - 561-7
AB  - The molecular forms of estrogen receptor (ER) in estrogen-responsive mouse Leydig 
      cell line (B-1) have been examined in relation to their biological activity. ER 
      was predominantly recovered in the nuclear fraction upon homogenization even 
      after cells were precultured in the absence of E2 and Phenol Red. This unoccupied 
      nuclear ER (ERn) whose hormone binding ability was extremely thermostable could 
      be extracted with 0.4 M KCl. This stability enabled us to determine hydrodynamic 
      parameters in the ligand-free condition. The Stokes radius and sedimentation 
      constant of this ERn in high salt condition were 5.5 nm and 6.0S, respectively, 
      resulting in its molecular weight of 140,000. Sodium dodecyl 
      sulfate-polyacrylamide gel electrophoresis of ER labeled with [3H]tamoxifen 
      aziridine gave a single band of 65,000 Da, indicating that this ERn had a 
      oligomer structure similar to that of transformed nuclear ER complexed with 
      estrogen in the putative target cells. Therefore, we further examined the 
      possibility that this ERn in B-1 cells can activate estrogen-responsive genes 
      without any aid from estrogen. Estrogen responsive element-thymidine kinase 
      promoter-chloramphenicol acetyltransferase fusion gene (ERE-tk-CAT) was 
      transfected into B-1 cells. CAT activity was enhanced only in cells stimulated 
      with estrogen. It may be concluded from these results that transformed ERn can be 
      formed in the absence of estrogen but that binding to estrogen may be required in 
      order to exert its biological activity.
FAU - Miyashita, Y
AU  - Miyashita Y
AD  - Third Department of Internal Medicine, Osaka University Hospital, Japan.
FAU - Hirose, T
AU  - Hirose T
FAU - Kouhara, H
AU  - Kouhara H
FAU - Kishimoto, S
AU  - Kishimoto S
FAU - Matsumoto, K
AU  - Matsumoto K
FAU - Sato, B
AU  - Sato B
LA  - eng
PT  - Journal Article
PL  - England
TA  - J Steroid Biochem
JT  - Journal of steroid biochemistry
JID - 0260125
RN  - 0 (Receptors, Estrogen)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Biological Transport
MH  - Cell Line
MH  - Cell Nucleus/metabolism
MH  - Cytosol/metabolism
MH  - DNA/genetics
MH  - Gene Expression Regulation
MH  - Hot Temperature
MH  - Leydig Cells/*metabolism
MH  - Male
MH  - Mice
MH  - Molecular Sequence Data
MH  - Plasmids/genetics
MH  - Receptors, Estrogen/genetics/*metabolism
EDAT- 1990/04/01 00:00
MHDA- 1990/04/01 00:01
CRDT- 1990/04/01 00:00
PHST- 1990/04/01 00:00 [pubmed]
PHST- 1990/04/01 00:01 [medline]
PHST- 1990/04/01 00:00 [entrez]
AID - 10.1016/0022-4731(90)90199-3 [doi]
PST - ppublish
SO  - J Steroid Biochem. 1990 Apr;35(5):561-7. doi: 10.1016/0022-4731(90)90199-3.