Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a functional and molecular analysis of nine oncocytic tumors of the human thyroid. In all the abundance of mitochondria observed ultrastructurally was accompanied by an increase in enzymatic activities of respiratory complexes 1 (NADH dehydrogenase), 11 (succinate dehydrogenase) IV (cytochrome c oxidase), and V (ATPase). Western blot analysis failed to detect uncoupling protein in the tumors. The elevated respiratory enzyme activities were paralleled by an increase in the mitochondrial DNA content. Restriction analysis of mitochondrial DNA gave no indication of heteroplasmy or other gross alterations. We conclude that the mitochondrial proliferation in oncocytic tumors is probably not the result of a compensatory mechanism for the deficiency in enzyme complexes of the mitochondrial respiratory chain.
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PMID:Functional and molecular analysis of mitochondria in thyroid oncocytoma. 167 11

The relative abundance of the mitochondrial-encoded mRNAs for cytochrome c oxidase subunit II and NADH dehydrogenase subunit I was lower in brown adipose tissue (BAT) from lactating rats than in virgin controls. This decrease was in parallel with a significant decrease in mitochondrial 16 S rRNA levels and in the relative content of mitochondrial DNA in the tissue. BAT from lactating rats showed lowered mRNA expression of the nuclear-encoded genes for the mitochondrial uncoupling protein, subunit IV of cytochrome c oxidase and the adenine nucleotide translocase isoforms ANT1 and ANT2, whereas mRNA levels for the ATP synthase beta-subunit were unchanged. However, the relative content of this last protein was lower in BAT mitochondria from lactating rats than in virgin controls. It is concluded that lactation-induced mitochondrial hypotrophy in BAT is associated with a co-ordinate decrease in the expression of the mitochondrial genome and nuclear genes for mitochondrial proteins. This decrease is caused by regulatory events acting at different levels, including pre- and post-transcriptional regulation. BAT appears to be a useful model with which to investigate the molecular mechanisms involved in the co-ordination of the expression of the mitochondrial and nuclear genomes during mitochondrial biogenesis.
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PMID:Co-ordinate decrease in the expression of the mitochondrial genome and nuclear genes for mitochondrial proteins in the lactation-induced mitochondrial hypotrophy of rat brown fat. 894 28

The enzyme S-nitrosoglutathione reductase (GSNOR) has an important role in the metabolism of S-nitrosothiols (SNO) and, consequently, in the modulation of nitric oxide (NO)-mediated processes. Although the mitochondrial electron transport chain is an important target of NO, the role of GSNOR in the functionality of plant mitochondria has not been addressed. Here, we measured SNO content and NO emission in Arabidopsis thaliana cell suspension cultures of wild-type (WT) and GSNOR overexpressing (GSNOR(OE)) or antisense (GSNOR(AS)) transgenic lines, grown under optimal conditions and under nutritional stress. Respiratory activity of isolated mitochondria and expression of genes encoding for mitochondrial proteins were also analyzed. Under optimal growth conditions, GSNOR(OE) had the lowest SNO and NO levels and GSNOR(AS) the highest, as expected by the GSNO-consuming activity of GSNOR. Under stress, this pattern was reversed. Analysis of oxygen uptake by isolated mitochondria showed that complex I and external NADH dehydrogenase activities were inhibited in GSNOR(OE) cells grown under nutritional stress. Moreover, GSNOR(OE) could not increase alternative oxidase (AOX) activity under nutritional stress. GSNOR(AS) showed constitutively high activity of external NADH dehydrogenase, and maintained the activity of the uncoupling protein (UCP) under stress. The alterations observed in mitochondrial protein activities were not strictly correlated to changes in gene expression, but instead seemed to be related with the SNO/NO content, suggesting a post-transcriptional regulation. Overall, our results highlight the importance of GSNOR in modulating SNO and NO homeostasis as well mitochondrial functionality, both under normal and adverse conditions in A. thaliana cells.
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PMID:Modulation of mitochondrial activity by S-nitrosoglutathione reductase in Arabidopsis thaliana transgenic cell lines. 2320 78

Brown adipose tissue (BAT) is specialized in non-shivering thermogenesis through the expression of the mitochondrial uncoupling protein-1 (UCP1). In this paper, we describe the relationship between UCP1 and proteins involved in ATP synthesis. By the use of BATIRKO mice, which have enhanced UCP1 expression in BAT, an increase in ATP synthase as well as in ubiquinol cytochrome c reductase levels was observed. Alterations in mitochondrial mass or variations in ATP levels were not observed in BAT of these mice. In addition, using a protocol of brown adipocyte differentiation, the concerted expression of UCP1 with ATP synthase was found. These two scenarios revealed that increases in the uncoupling machinery of brown adypocites must be concomitantly followed by an enhancement of proteins involved in ATP synthesis. These concerted changes reflect the need to maintain ATP production in an essentially uncoupling cell type.
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PMID:Concerted expression of the thermogenic and bioenergetic mitochondrial protein machinery in brown adipose tissue. 2360 15