Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.1.17 (ornithine decarboxylase)
 6,351 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

TfmLac, a new occurrence of the X-linked mutation testicular feminization, has been isolated in a stock of mice and mapped to the same region as the original TfmH mutation. We compared these two mutants to determine if there are differences in their putative residual androgen receptors or androgen responsiveness. Such differences have been reported for Tfm mutations in humans. We found no evidence for induction of ornithine decarboxylase (ODC) activity in TfmLac despite androgen treatment for up to 3 weeks. This is in agreement with findings for TfmH. Both of these mutants expressed small amounts of androgen binding activity which shared some properties with the normal androgen receptors in mouse kidney. The binding was distinguishable between the two mutants, however, as determined by hormone saturation experiments utilizing DNA-cellulose chromatography. These findings confirm the independence of the two mutations and are consistent with their being allelic: both result in severe deficits of androgen binding and response.
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PMID:TfmLac: a second isolation of testicular feminization in mice. 340 76

To investigate the mechanisms by which androgens regulate ornithine decarboxylase (OrnDCase; L-ornithine carboxy-lyase, EC 4.1.1.17) in mouse kidney, a cDNA clone encoding OrnDCase mRNA was prepared. Purification of OrnDCase mRNA from kidneys of androgen-treated mice was accomplished by immunoadsorption of renal polysomes to a protein A-Sepharose column and enrichment for poly(A)-containing RNA by oligo(dT)-cellulose. Double-stranded cDNA synthesized from this mRNA was inserted into the Pst I site of plasmid pBR322 by using oligo(dG . dC)-tailing and was propagated in Escherichia coli. Plasmids containing cDNA sequences coding for OrnDCase were identified by differential colony hybridization, by radioimmunological detection of OrnDCase-like antigens in bacterial cultures, and by cell-free translation of hybrid-selected mRNA followed by immunoprecipitation with monospecific OrnDCase antiserum. A restriction endonuclease fragment of the selected plasmid DNA (pODC54) was labeled by nick-translation and used to study changes in OrnDCase mRNA concentration. After a single dose of testosterone, renal OrnDCase mRNA concentration increased as soon as 6 hr and peaked 24 hr after steroid injection, as measured by RNA blot hybridization. Continuous androgen treatment for 4 days resulted in a 10- to 20-fold increase in OrnDCase mRNA concentration in normal animals, but no induction of this mRNA was detected in mice that have an inherent defect of the androgen receptor (testicular feminization). These results indicate that androgens regulate OrnD-Case synthesis in mouse kidney, at least in part, by increasing OrnDCase mRNA accumulation.
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PMID:Androgen induction of ornithine decarboxylase mRNA in mouse kidney as studied by complementary DNA. 636 88