Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HTC cell variants chosen for their lack of tyrosine aminotransferase (EC 2.6.1.5) (TAT) induction by glucocorticoids were tested for interrelated effects on other glucocorticoid responses: TAT induction by dibutyryl cyclic AMP (dBcAMP) +/- dexamethasone, glutamine synthetase (GS) induction, cyclic nucleotide phosphodieterase (PDE) suppression, inhibition of alpha-aminoisobutyric acid (AIB) uptake, inhibition of plasminogen activator (PA), and induction of mouse mammary tumor virus (MTV). Loss of TAT induction by steroid was accompanied by loss of TAT induction by dBcAMP and of PDE suppression by steroid. In addition, subclones of MTV-infected cells were examined for the effect of the virus on glutamine synthetase (GS) and TAT induction. The virus had no effect on their induction in wild-type cells and no effect on GS induction in the variants. One MTV-infected subclone from a TAT variant, however, showed significant return of TAT induction.
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PMID:Unlinked control of multiple glucocorticoid-induced processes in HTC cells. 3 58

By comparing the 5'-flanking region of the porcine gene for the urokinase form of plasminogen activator with those of other cAMP-regulated genes, we identify a 29-nucleotide sequence that is tentatively proposed as the cAMP-regulatory unit. Homologous sequences are present (i) in the cAMP-regulated rat tyrosine aminotransferase, prolactin, and phosphoenolpyruvate carboxykinase genes and (ii) 5' to the transcription initiation sites of cAMP-regulated Escherichia coli genes. From this we conclude that the expression of cAMP-responsive genes in higher eukaryotes may be controlled, as in E. coli, by proteins that form complexes with cAMP and then show sequence-specific DNA-binding properties. The complex formed by cAMP and the regulatory subunit of the type II mammalian protein kinase might be one candidate for this function. Based on several homologies we suggest that this subunit may have retained both the DNA-binding specificity and transcription-regulating properties in addition to the nucleotide-binding domains of the bacterial cAMP-binding protein. If this were so, dissociation of protein kinase by cAMP would activate two processes: (i) protein phosphorylation by the catalytic subunit and (ii) transcription regulation by the regulatory subunit.
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PMID:Gene expression and cAMP. 299 82

Dexamethasone, a synthetic glucocorticoid, decreases the plasminogen activator (PA) activity of HTC rat hepatoma cells in tissue culture. Paradoxically, dexamethasone enhances the cyclic nucleotide stimulation of PA activity in these cells 2-4-fold. In this report, we investigated whether this paradoxical glucocorticoids as the induction of tyrosine aminotransferase activity. We compared the concentration-dependences for several classes of steroids, previously classified as full agonists, partial agonists, antagonists or inactive steroids with respect to induction of the transaminase, for both enhancement of cyclic nucleotide stimulation of PA activity and induction of tyrosine aminotransferase activity in parallel cultures. The full agonists dexamethasone and cortisol, the partial agonists deoxycorticosterone and 11 beta-hydroxyprogesterone, the inactive steroid tetrahydrocortisol, and the antagonist 17 alpha-methyltestosterone exhibited similar potencies with respect to both phenomena. Furthermore, when cells were incubated with both dexamethasone and 17 alpha-methyltestosterone, the latter blocked enhancement by dexamethasone in a concentration-dependent fashion. We conclude that glucocorticoid enhancement of cyclic nucleotide stimulation of PA activity is mediated by the same glucocorticoid receptors which mediate direct regulatory effects.
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PMID:Paradoxical effects of glucocorticoids on regulation of plasminogen activator activity. Mediation by glucocorticoid receptors. 614 81