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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1985-6-17
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pubmed:abstractText |
A steroid binding protein (Mr = 110,000) has previously been identified in the plasma membrane of Xenopus laevis oocytes by photoaffinity labeling with [3H]R5020. In order to further characterize this steroid receptor, the photoaffinity labeled receptor protein was solubilized with 0.1% Brij 35. The solubilized labeled receptor yielded an approximate mol. wt of 102,000 +/- 2,000 by sucrose density gradient centrifugation, suggesting that the solubilized receptor exists as a monomer. RU 486, a synthetic progestin antagonist for mammalian cytosolic receptor systems, inhibited up to 70% of [3H] R5020 photoaffinity binding to the 110,000-Dalton receptor with an IC50 of 5 microM and induced germinal vesicle breakdown (GVBD) with an EC50 of 9.0 +/- 0.6 microM. GVBD induced by RU 486 was slower than with progesterone, and RU 486 was less powerful than progesterone. Micromolar concentrations of RU 486 also potentiated GVBD induced by sub-optimal concentrations of progesterone or R5020. Furthermore, RU 486 inhibited oocyte plasma membrane adenylate cyclase with an apparent IC50 of 7.5 +/- 2.5 microM. The close correlation of the EC50 value for RU 486 induction of GVBD with the IC50 values for inhibition of [3H]R5020 photoaffinity labeling of the 110,000-Dalton receptor and inhibition of adenylate cyclase activity further supports the physiological significance of the oocyte plasma membrane steroid receptor.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Affinity Labels,
http://linkedlifedata.com/resource/pubmed/chemical/Estrenes,
http://linkedlifedata.com/resource/pubmed/chemical/Mifepristone,
http://linkedlifedata.com/resource/pubmed/chemical/Promegestone,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Steroid
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0022-4731
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
22
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
419-26
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:4039395-Affinity Labels,
pubmed-meshheading:4039395-Animals,
pubmed-meshheading:4039395-Cell Membrane,
pubmed-meshheading:4039395-Estrenes,
pubmed-meshheading:4039395-Female,
pubmed-meshheading:4039395-Mifepristone,
pubmed-meshheading:4039395-Molecular Weight,
pubmed-meshheading:4039395-Oocytes,
pubmed-meshheading:4039395-Photochemistry,
pubmed-meshheading:4039395-Promegestone,
pubmed-meshheading:4039395-Receptors, Steroid,
pubmed-meshheading:4039395-Xenopus laevis
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pubmed:year |
1985
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pubmed:articleTitle |
Studies of a plasma membrane steroid receptor in Xenopus oocytes using the synthetic progestin RU 486.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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