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)

A mitochondrial extract from Leishmania tarentolae directs the incorporation of uridylate (U) residues within the pre-edited domain of synthetic cytochrome b (CYb) and NADH dehydrogenase subunit 7 mRNA. This has several characteristics of an in vitro RNA editing activity, but no direct evidence for involvement of guide RNAs was obtained. Inhibition by micrococcal nuclease suggests a requirement for some type of endogenous RNA. The limitation of internal U-incorporation to the pre-edited region in the CYb mRNA and the inhibition by deletion or substitution of both mRNA anchor sequences for CYb gRNA-I and -II could be consistent either with a gRNA-mediated process or a secondary structure-mediated process. A low level of incorporation of [alpha-32P]CTP occurs at the same sites as UTP. Internal U-incorporation activity is selectively inhibited by heterologous RNAs, suggesting an involvement of low affinity RNA-binding proteins which can be competed by the added RNA.
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PMID:In vitro RNA editing-like activity in a mitochondrial extract from Leishmania tarentolae. 782 90

Aurintricarboxylic acid (ATA), an inhibitor of Ca(2+)-dependent endonuclease activity, is often used to implicate a role for increased intracellular calcium in mechanistic toxicology studies. We report here on the ability of ATA to inhibit the activity of several NAD(H)/NADP(H)-requiring enzymes (purified or cellular homogenates), including lactic dehydrogenase, alcohol dehydrogenase, cytochrome c reductase, ethoxycoumarin o-dealkylase, isocitric dehydrogenase, glutathione reductase and glucose-6-phosphate dehydrogenase. These results were compared with the ability of ATA to inhibit micrococcal nuclease and rat liver Ca(2+)-dependent endonuclease activity in similar incubations. With the exception of alcohol dehydrogenase, ATA was a potent inhibitor of each of the purified enzymes, with IC50s ranging from 0.5 to 82 microM. In cell homogenates, however, ATA was from 10 to 100-fold less potent at inhibiting these enzymes. When exogenous protein was added to purified enzyme incubations, the effect of ATA was similarly diminished. Our results demonstrate that ATA inhibits a wide range of NAD(H)/NADP(H)-requiring enzymes in in vitro incubations using purified enzymes, but that the inhibitory effects are markedly reduced in incubations which more closely resemble a cellular milieu.
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PMID:Inhibition of NAD(H)/NADP(H)--requiring enzymes by aurintricarboxylic acid. 855 68

An mRNA-dependent cell-free system has been developed from HepG2 cells by hydrolysis of endogenous mRNA with micrococcal nuclease. When supplied with RNA extracted from HepG2 cells, the system synthesized liver specific proteins such as albumin and apolipoprotein B100. Significant amounts of microsomes were also detected in the lysate by measuring NADH-cytochrome c reductase activity and ultracentrifugation. Protease protection assays showed the capability of the HepG2 lysate to translocate newly-synthesized proteins such as apolipoprotein Al, albumin, and apoB into the microsomes as they were protected from digestion with exogenously added protease K, but not protected in the presence of protease K and Triton X-100. The system also proved to be very active toward translation of exogenous mRNAs as evidenced by efficient translation of brome mosaic virus RNA. The HepG2 translation-translocation system appears to provide a unique homologous system for studies on the biogenesis of liver specific proteins, particulary apoB100.
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PMID:In vitro translation and translocation of apolipoprotein B in a cell-free system from HepG2 cells. 894 65