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109. Location of the estrogen receptor on nuclease digested chromatin fragments
xxxvii
Abstracts 109. Location of the estrogen receptor on nuclease digested fragments. B.-Inst. of Endocr. C. M. Lunenfeld Geier A., Haimsolen Tel-Habhomer, Israel.
chromatin Sheba
Med.
Ctr.
The location of the estrogen receptor relative to the nucleosomal orgaNuclei were isonization of chromatin was st-udied in MCF-'j' cell +ine. lated from cells which were exposed for 1 h to ( H)-estradiol, washed and further cultured in fresh media for additional 0,1,2,3,4,5, days.
The distribution oE the receptor on the chromatin fragments following micrococcal nuclease digestion, using a s
110.
INTERACTION OF NORETHISTERONE (NET) LULAR STEROIDS RECEPTORS:\. Larrea F., Escobar, N., Lince, M., of Reproductive Biology. Inst.Natl
WITH and .de
EXTRACELLULAR Pirez-Palacios, la Nutrici6n.
AND
INTRACEL -
G. Department Mexico City.
The ability of NET to interact with serum binding proteins from several mammalian species including man, and with intracellular steroids recee tors was studied. The aim of the study was to investigate the mechanism of antigonadotropic activity of NET in non-estrogen sensitized fe wistar rats. male castrate Serum from human and other species was in g cubated with H-dihydrotestosterone (DHT) or 3H-cortisol (F) with and Y without increasing concentrations of unlabeled NET, DHT and F. Displace ment and double-reciprocal plots demonstrated the specific interactionof NET to TeBG and CBG at the binding site for natural occurring steroids Identification of receptors for NET at the pituitary was performed by nuclear exchange assay with 3H-Ez or other labeled steroids. The results demostrated the specific ceptors similar to those explain the antigonadotropic terone receptors.
-‘-
Supported
by
Rockefeller
interaction obtained at activity
Foundat
ion
of NET with nuclear estradiol uterine level. These results of NET in rats depleted of
re
-
may proges -
Grant.
111. DNA-BINDING OF HUMAN UTERINE ESTROGEN RECEPTOR. Abe Akademi Lukola, A. and Punnonen, R.- Department of Biochemistry, Turku University Central and Department of Obstetrics and Gynaecology, Hospital, Turku, Finland. The nuclear and DNA-binding activity of the human uterine estrogen receptor is lost by the proteolytical degradation of the 9 S receptor form. Of the different protease inhibitors tested (DFP,PMSF,TPCK,TLCK) only DFP was able to inhibit the receptor degradation and thus allow stabilizes the 9 S DNA- and nuclear binding to occure. Also molybdate estrogen receptor but it blocks the DNA-binding activity. Vanadate, an In the inhibitor of ATPase activity, does not block the DNA-binding. presence of vanadate alone the estrogen receptor is, however, not actionly when the proteolytical vated. Vanadate increases the DNA-binding activity is blocked. The presence of levamisole does not result in increased DNA-binding wether DFP is present or not. Phosphorylation may play a role in the activation of the human uterine estrogen receptor but to confirm this requires studies with highly purified receptors.
Abstracts 109. Location of the estrogen receptor on nuclease digested fragments. B.-Inst. of Endocr. C. M. Lunenfeld Geier A., Haimsolen Tel-Habhomer, Israel.
chromatin Sheba
Med.
Ctr.
The location of the estrogen receptor relative to the nucleosomal orgaNuclei were isonization of chromatin was st-udied in MCF-'j' cell +ine. lated from cells which were exposed for 1 h to ( H)-estradiol, washed and further cultured in fresh media for additional 0,1,2,3,4,5, days.
The distribution oE the receptor on the chromatin fragments following micrococcal nuclease digestion, using a s
110.
INTERACTION OF NORETHISTERONE (NET) LULAR STEROIDS RECEPTORS:\. Larrea F., Escobar, N., Lince, M., of Reproductive Biology. Inst.Natl
WITH and .de
EXTRACELLULAR Pirez-Palacios, la Nutrici6n.
AND
INTRACEL -
G. Department Mexico City.
The ability of NET to interact with serum binding proteins from several mammalian species including man, and with intracellular steroids recee tors was studied. The aim of the study was to investigate the mechanism of antigonadotropic activity of NET in non-estrogen sensitized fe wistar rats. male castrate Serum from human and other species was in g cubated with H-dihydrotestosterone (DHT) or 3H-cortisol (F) with and Y without increasing concentrations of unlabeled NET, DHT and F. Displace ment and double-reciprocal plots demonstrated the specific interactionof NET to TeBG and CBG at the binding site for natural occurring steroids Identification of receptors for NET at the pituitary was performed by nuclear exchange assay with 3H-Ez or other labeled steroids. The results demostrated the specific ceptors similar to those explain the antigonadotropic terone receptors.
-‘-
Supported
by
Rockefeller
interaction obtained at activity
Foundat
ion
of NET with nuclear estradiol uterine level. These results of NET in rats depleted of
re
-
may proges -
Grant.
111. DNA-BINDING OF HUMAN UTERINE ESTROGEN RECEPTOR. Abe Akademi Lukola, A. and Punnonen, R.- Department of Biochemistry, Turku University Central and Department of Obstetrics and Gynaecology, Hospital, Turku, Finland. The nuclear and DNA-binding activity of the human uterine estrogen receptor is lost by the proteolytical degradation of the 9 S receptor form. Of the different protease inhibitors tested (DFP,PMSF,TPCK,TLCK) only DFP was able to inhibit the receptor degradation and thus allow stabilizes the 9 S DNA- and nuclear binding to occure. Also molybdate estrogen receptor but it blocks the DNA-binding activity. Vanadate, an In the inhibitor of ATPase activity, does not block the DNA-binding. presence of vanadate alone the estrogen receptor is, however, not actionly when the proteolytical vated. Vanadate increases the DNA-binding activity is blocked. The presence of levamisole does not result in increased DNA-binding wether DFP is present or not. Phosphorylation may play a role in the activation of the human uterine estrogen receptor but to confirm this requires studies with highly purified receptors.