Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous work using microinjection into single cells of the tomato aurea mutant demonstrated that phytochrome A-dependent activation of rbcS and chs genes was mediated by calcium and cGMP, respectively. This work sought to identify promoter cis-elements that respond to these two small molecules. Box II and Unit I, derived from rbcS-3A and chs promoters, respectively, were previously shown to function as light-responsive cis-elements. Eleven copies of Box II and four copies of Unit I were linked 5' to the -90 and -46 35 S promoters, respectively, and, both constructs were fused to the beta-glucuronidase (GUS) reporter gene. GUS activities were obtained upon coinjection of either Box II/-90GUS or Unit I/-46GUS with oat phytochrome A (phyA) and GTP gamma S, an activator of heterotrimeric G proteins. The activation of Box II/-90GUS by phyA was insensitive to the cGMP antagonist, Rp-cGMPS, although anthocyanin accumulation, but not chloroplast development, was totally blocked in the injected cells. Consistent with this result, calcium, but not cGMP, induced Box II/-90GUS activity. In contrast to Box II/-90GUS, phyA-dependent activation of Unit I/-46GUS activity was blocked by Rp-cGMPS. Moreover, cGMP, not calcium, induced Unit I/-46GUS activity. Control experiments showed that -90 GUS and -46 GUS were inactive in the presence of calcium and cGMP, respectively. These results provide evidence that Box II and Unit I are targets of the calcium and cGMP pathways, respectively. Interestingly, calcium activation of Box II/-90GUS was repressed by a high concentration of cGMP and cGMP induction of Unit I/-46GUS was blocked by a high concentration of calcium/CaM. Thus, these two small cis-elements can also serve as targets of the reciprocal control mechanisms that operate to regulate the activities of the two phyA signaling branches.
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PMID:Calcium and cGMP target distinct phytochrome-responsive elements. 901 Oct 95

The anti-cancer drug cyclophosphamide (CYP) is nephrotoxic besides being urotoxic thereby limiting its clinical utility. Since the nephrotoxicity of CYP is less common compared to its urotoxicity, not much importance has been given for the study of mechanism of CYP-induced nephrotoxicity. The aim of the present study is to investigate the possible role of lysosomal enzymes in CYP-induced renal damage. Adult female Wistar rats weighing 200-250 g were used for the study. The rats were administered single-intraperitoneal injection of CYP at the dose of 150 mg/kg body wt and sacrificed at various time intervals 6, 16 or 24 h after the dose of CYP. The control rats were administered saline alone. Nephrotoxicity was assessed by measuring plasma creatinine and urea and histopathology of the kidney. The kidney was weighed and used for the assay of lysosomal enzymes namely acid phosphatase, beta-glucuronidase and N-acetylglucosaminidase and total protein content. Histologically, the CYP-treated rat kidneys showed progressive renal damage with increase in time after treatment. Glomerular nephritis, cortical tubular vacuolization and interstitial edema were observed in the CYP-treated rats. Surprisingly, a significant drastic decrease (instead of an increase) in the activities of lysosomal enzymes was observed in the kidneys of CYP-treated rats at 16 and 24 h as compared with the control. A highly significant increase (270%) in protein content was observed in the kidneys of the CYP-treated rats as compared with the control. Decrease in the activities of lysosomal protein digestive enzymes may contribute to CYP-induced renal damage. The accumulation of abnormal amounts of the protein in the kidney may be due at least in part to defect in lysosomal enzyme activity and contribute to renal damage.
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PMID:Effect of cyclophosphamide treatment on selected lysosomal enzymes in the kidney of rats. 1768 19


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