Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glucocorticoids inhibit stimulus-evoked ACTH secretion by the rapid induction of new protein(s) that suppress intracellular free calcium signals. The present study examined whether the calcium receptor protein, calmodulin, is induced by glucocorticoids in the mouse pituitary corticotrope tumor (AtT20 D16:16) cell line. Treatment of AtT20 D16:16 cells with the synthetic glucocorticoid dexamethasone markedly (up to 10-fold) increased the level of a single (approximately 1.6kb) calmodulin mRNA 90 min after the application of steroid. Puromycin applied 15 min before and during dexamethasone treatment blocked the induction of this mRNA, suggesting that additional glucocorticoid induced transcription factor proteins may be required for enhanced calmodulin gene transcription. A two-fold increase in the intensity of an approximately 18K immunoreactive calmodulin protein band was detected by immunoblotting at 90 min after dexamethasone administration. Corticotropin releasing factor, added for 30 min at the start of steroid treatment, prevented the increase of calmodulin mRNA, as well as the suppression of corticotropin releasing factor-evoked ACTH release caused by dexamethasone. These data suggest that calmodulin may be involved in the early phase of glucocorticoid inhibition of pituitary ACTH release.
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PMID:Early glucocorticoid induction of calmodulin and its suppression by corticotropin-releasing factor in pituitary corticotrope tumor (AtT20) cells. 133 64

The generation of met-enkephalin (Tyr1-Gly2-Gly3-Phe4-Met5) from met-enkephalin-Arg6-Phe7 and subsequent degradation of the liberated peptides to the free amino acids by rat brain cortical synaptosomes in vitro was demonstrated by HPLC and amino acid analyses. Kinetic measurements of the individual steps of met-enkephalin processing and degradation upon incubation with synaptosomes revealed the following sequence of cleavage: 1. Hydrolysis of the Met5-Arg6 peptide bond, generating met-enkephalin and the dipeptide Arg-Phe. Captopril and EDTA inhibit this reaction. 2. Hydrolysis of the Tyr1-Gly2 peptide bond, generating Tyr and a tetrapeptide. Puromycin (ID50 = 5 X 10(-5) M) and parahydroxymercuribenzoate (ID50 = 5 X 10(-4) M) inhibit this reaction. 3. Hydrolysis of the Gly3-Phe4 peptide bond. Parahydroxymercuribenzoate (ID50 = 5 X 10(-4) M) inhibits this reaction completely. 1 mmol liter-1 Puromycin does not inhibit this reaction. 4. Hydrolysis of the Phe4-Met5 peptide bond. 5. Hydrolysis of the Gly2-Gly3 peptide bond. The pH optimum of all cleavage reactions was found to be around 7.8.
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PMID:Processing and degradation of met-enkephalin by peptidases associated with rat brain cortical synaptosomes. 635 99