Human regulatory gene for inducible tyrosine aminotransferase in rat-human hybrids.
The inducibility of tyrosine aminotransferase (EC 2.6.1.5) by corticosteroid hormones in rat-human hybrid clones was studied. The presence of human X chromosome activity in the cells was always associated with the suppression of tyrosine aminotransferase inducibility in all the clones examined. Negative correlation between the human X chromosome and inducibility of the enzyme was clearly established. Corticosteroid receptor was present to the same extent in hybrid cell clones that either contained or lost the human X chromosome. The human repressor for inducible tyrosine aminotransferase has a linkage relationship with glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and hypoxanthine-guanine-phosphoribosyltransferase (EC 2.4.2.8) and, therefore, can be assigned to the X chromosome.
D000818:Animals; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D002999:Clone Cells; D003907:Dexamethasone / Q000494:pharmacology; D004622:Embryo, Mammalian; D004790:Enzyme Induction / Q000187:drug effects; D004794:Enzyme Repression; D005260:Female; D005809:Genes, Regulator; D008040:Genetic Linkage; D005954:Glucosephosphate Dehydrogenase; D006801:Humans; D006822:Hybrid Cells / Q000201:enzymology*; D007621:Karyotyping; D008113:Liver Neoplasms; D008168:Lung; D010430:Pentosyltransferases; D051381:Rats; D012730:Sex Chromosomes; D014444:Tyrosine Transaminase / Q000096:biosynthesis*
D003907:Dexamethasone; D005954:Glucosephosphate Dehydrogenase; D010430:Pentosyltransferases; D014444:Tyrosine Transaminase