Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the molecular basis for changes in aromatase (P450arom) activity in rat ovarian follicles and corpora lutea, seven clones for rat P450arom cDNA have been identified and isolated from a rat granulosa cell lambda gt11 cDNA expression library using a 62 mer deoxyoligonucleotide probe (derived from an amino acid sequence of purified human placental aromatase) and a human placental P450arom cDNA probe. One of the rat P450arom cDNA clones contained an insert 1.2 kb in size. Both the human 1.8 kb cDNA and the rat 1.2 kb cDNA probes hybridized to a single species of P450arom mRNA that was 2.6 kb in size. Northern blot analysis revealed that corpora lutea isolated on day 15 of pregnancy contained high amounts of P450arom mRNA, whereas granulosa cells of antral follicles of hormonally primed, hypophysectomized rats (i.e., those from which mRNA was isolated to construct the cDNA library) contained only low amounts of P450arom mRNA. The lower amounts of P450arom in granulosa cells of preovulatory follicles in the estradiol-follicle-stimulating hormone primed hypophysectomized rats were unexpected because follicles incubated in medium containing testosterone substrate produce more estradiol than do corpora lutea isolated on day 15 of pregnancy and incubated under similar conditions. Additional studies will determine the hormonal events responsible for the elevated amounts and constitutive maintenance of P450arom mRNA and aromatase activity in luteal cells in vivo and in vitro.
Steroids
PMID:Hormonal regulation of estradiol biosynthesis, aromatase activity, and aromatase mRNA in rat ovarian follicles and corpora lutea. 314 64

The interactions of estrogen receptor (ER) with monoclonal antibody (Mab) F9, developed against a synthetic 30-mer hybrid oligopeptide, were determined in the presence or absence of Mab NMT-1, raised against 15-mer peptide from the N-terminal A/B region (amino acids 140- 154) or Mab 213, raised to a peptide AT3 in the DNA-binding domain (amino acids 247-263). Mab F9 bound ER and formed a complex sedimenting at the approximately 11S region of the gradients. Mabs 213 and NMT-1 bound ER and formed complexes sedimenting at approximately 7S and 9S, respectively. Preincubation of ER with Mab 213, followed by reincubation with Mab F9, resulted in a complex sedimenting at the approximately 11S region of the gradients. Similarly, preincubation of ER with Mab NMT-1 followed by reincubation with Mab F9 also produced an approximately 11S complex on the gradients. These observations suggest that binding of Mab F9 to ER induced conformational changes causing the release of Mab 213 and Mab NMT-1 from ER. Furthermore, binding of Mab NMT-1 to the A/B region of ER also produced conformational changes causing the release of Mab 213 from its epitope in the DNA-binding region. These results indicate that binding of Mab F9 and Mab NMT-1, with epitopes located within amino acids 140-154 of the A/B region of ER, induced conformational changes in the DNA-binding domain, as determined by the inability of Mab 213 to remain bound to its epitope. These data further suggest that the DNA-binding region is sensitive to conformational changes induced in the native protein.
Steroids 1996 Sep
PMID:Binding of site-directed monoclonal antibodies to an epitope located in the A/B region (amino acids 140-154) of human estrogen receptor-induced conformational changes in an epitope in the DNA-binding domain. 888 22

A chemically synthesized 15-mer oligopeptide derived from the N terminus of high affinity progesterone-binding membrane site(s) from porcine liver was used to generate site-specific antibodies. Western blotting experiments confirmed the specificity of the anti-peptide serum obtained. In further investigations this antiserum was used for the identification of the native progesterone-binding membrane protein complex that represents an oligomer with an apparent molecular mass of about 200 kDa. In temperature-induced Triton X-114 phase separation experiments combined with Western-blotting, the progesterone-binding site was identified as an hydrophobic (integral) membrane protein. In addition, in Western blotting analyses the antiserum reacted with the progesterone-binding or related proteins in membrane fractions from a wide array of different tissues in various species.
Steroids 1998 Feb
PMID:Characterization of high affinity progesterone-binding membrane proteins by anti-peptide antiserum. 951 22