Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.31.1 (micrococcal nuclease)
 2,818 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oviduct cells from estradiol-treated chicks were grown in primary culture. After 3-5 days of culture in medium containing estradiol, 90% of the cellular progesterone binding sites were detected in the cytosol. After exposure to [3H]progesterone at 37 degrees C, 80% of the progesterone binding sites were found in nuclear fractions. Progesterone receptor phosphorylation was assessed after incubating the cells with [32P]orthophosphate. Receptor components were immunoprecipitated with a specific polyclonal antibody (IgG-G3) and analyzed by NaDodSO4/PAGE and autoradiography. In the cytosol, constant amounts of 32P-labeled 110-kDa subunit (the B subunit, one of the progesterone-binding components of the receptor) and of the non-steroid-binding heat shock protein hsp90 were found, whether cells had been exposed to progesterone or not. No 32P-labeled 79-kDa subunit (the A subunit, another progesterone-binding subunit) was detected. Various procedures were used to solubilize nuclear progesterone receptor (0.5 M KCl, micrococcal nuclease, NaDodSO4), and in no case was 32P-labeled B subunit detected in the extracts. However, nonradioactive B subunit was detected by immunoblot in a nuclear KCl extract of progesterone-treated cells. These results suggest that the fraction of the B subunit that becomes strongly attached to nuclear structures is not phosphorylated upon exposure of cells to progesterone.
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PMID:Tightly bound nuclear progesterone receptor is not phosphorylated in primary chick oviduct cultures. 346 87

Oestrogen-primed and withdrawn chicks were injected with oestradiol benzoate, progesterone, and/or the anti-oestrogens tamoxifen and 4-hydroxytamoxifen. Oestrogen receptors were studied in oviduct chromatin solubilized by mild digestion of purified nuclei with micrococcal nuclease. After a single injection of oestradiol benzoate, ultracentrifugation on sucrose gradients of chromatin extracts labelled with [3H]-oestradiol showed two peaks of oestradiol binding sites, sedimenting at 13--14 S and 7--8 S. After repeated injections of oestradiol benzoate, the 13--14 S peak increased more than the 7--8 S peak. After injection of anti-oestrogen alone or together with oestradiol benzoate, no [3H]oestradiol-binding or 4-hydroxy[3H]tamoxifen-binding peaks were detected in the chromatin. Injection of progesterone also produced an increase of the 13--14 S and 7--8 S chromatin oestradiol receptor. Progesterone receptor could only by detected in chromatin early after progesterone administration, and it sedimented in density gradients with the 12 S mononucleosome fraction. Tamoxifen injected together with progesterone gave higher levels of 13--14 S oestrogen binding sites than did progesterone alone. The presence of a 13--14 S peak of oestrogen binding sites in hormonal situations which promote a biological response in the chick oviduct, and the absence of this peak after administration of anti-oestrogens, suggest that this subfraction of chromatin contains elements involved in gene regulation.
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PMID:Oestrogen and progesterone receptors in chick oviduct chromatin after administration of oestradiol, progesterone or anti-oestrogen. 712 60