ABSTRACT
The NADPH-dependent reduction activities of two paralogous pig AKR1C1s with and without 19 additional amino acid residues in C-terminus were evaluated against steroid hormones including 5a-dihydrotestosterone, testosterone, progesterone, androstenedione and 5a-androstane-3,17-dione, which act as substrates of the AKR1C1s. Among the hormones, the AKR1C1s exhibited the highest activity against 5a-dihydrotestosterone and the lowest activity against testosterone and progesterone. Furthermore, the AKR1C1s showed the largest differential activities against 5a-dihydrotestosterone, but no such change of activities was found against progestrone and testosterone. These results suggest that the C-terminal region of AKR1C1 plays an important effect in the reduction activities of pig AKR1C1. Thus, the differential activities of two AKR1C1 paralogs observed in the present study provide important insights in understanding the molecular evolution.
Subject(s)
20-Hydroxysteroid Dehydrogenases/chemistry , Animals , Enzyme Activation , Gonadal Steroid Hormones/chemistry , NADP/chemistry , Oxidation-Reduction , Structure-Activity Relationship , SwineABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of transcriptional inhibitors 5, 6-dichloro-1-b-D-ribofuranosylbenzimidazole (DRB) and alpha-Amanitin on the localization of Nrf2 in the nucleus.</p><p><b>METHODS</b>A549 cells were treated with DRB (50 mg/L) or alpha-Amanitin (2.5 mg/L)for 1 h and 6 h in serum-free medium, respectively. The expressions of Nrf2, HO-1, NQO1 and AKR1C were detected by Western blotting analysis. The localization of Nrf2 was determined by laser scanning confocal microscopy after cells were treated with either DRB or agr:-Amanitin for 1 h.</p><p><b>RESULTS</b>The expressions of Nrf2 and Nrf2-ARE gene batteries HO-1, AKR1C and NQO1 were decreased after 6 h treated with either DRB or alpha-Amanitin. The expression of SC35 was up-regulated but RNA Pol II was down-regulated; Y12 and NPC did not significantly change. The localization of Nrf2 in the cell nucleus did not change significantly.</p><p><b>CONCLUSION</b>DRB and alpha-Amanitin can down-regulate the expression of Nrf2 and its targeting proteins HO-1, AKR1C and NQO1, but may have no effect on the localization of Nrf2.</p>