Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Signal-transducing GTP-binding Proteins of Mammalian Heart and Lungs. Journal of Molecular and Cellular Cardiology (1989) 21 (Suppl I) 91-95. Three distinct G-proteins have been found in mammalian heart sarcolemma: Gi (alpha i = 40 kDa, beta = 36 kDa, and lambda less than 14 kDa), Gp (alpha p = 23 kDa, beta = 36 kDa, and lambda less than 14 kDa), and Gs (alpha s = 42 kDa). ADP-ribosylation of sarcolemmal alpha i by pertussis toxin (PT) or preincubation of sarcolemma with protein kinase C and PMA resulted in increased adenylate cyclase activity and blockade of GTP-dependent inhibition by carbachol whereas the GTP-dependent activating effect of isoproterenol on the adenylate cyclase was preserved. ADP-ribosylation of alpha i in sarcolemma by endogenous NADP-sensitive ADP-ribosyltransferase abolished the PT-induced ADP-ribosylation of alpha i. Gpp (NH)p attenuated the PT-induced ADP-ribosylation of alpha i and promoted the cholera toxin (CT)-induced ADP-ribosylation of alpha s. The CT-induced alpha s ADP-ribosylation was enhanced in the presence of heart cytosol. Soluble Gi- and Gs-proteins were identified in lung cytosol. The 40 kDa alpha i in membrane and soluble fractions was ADP-ribosylated by PT, while the soluble 42 kDa alpha s was ADP-ribosylated by CT in lung tissue. The ADP-ribosylation of soluble alpha i by PT-suppressed guanyl nucleotide binding to Gi. The apparent molecular mass of partially purified soluble Gi was 75 kDa.
J Mol Cell Cardiol 1989 Feb
PMID:Signal-transducing GTP-binding proteins of mammalian heart and lungs. 249 81

We have constructed a plasmid, pQS1, in which a mouse dihydrofolate reductase (5,6,7,8-tetrahydrofolate:NADP:oxidoreductase; EC 1.5.1.3; DHFR) cDNA is inserted in the unique PstI site of a gram-positive/gram-negative shuttle vector derived from pBR322. The cDNA is expressed under the control of the bla promoter, which, like most gram-negative bacterial genes, is considered not to be expressed in Bacillus subtilis, and its coding sequence is translated from a polycistronic message. We have selected in vivo and studied, in Escherichia coli and B. subtilis, expression mutants with promoter and ribosome binding site sequence mutations. One promoter mutation changes the third nucleotide of the -35 region from a C to a G. As expected, this substitution results in increased transcriptional activity in E. coli. In B. subtilis, this mutation induces the accumulation not only of a low but significant amount of dhfr mRNA but also of DHFR, demonstrating that binding strengths with a free energy as low as -9.4 kcal/mol are sufficient to promote ribosome binding in B. subtilis. The association of the promoter mutation (C-G) with a mutation which creates a strong B. subtilis ribosome binding site (-21 kcal/mol) results in the accumulation of a large amount of dhfr mRNA. This demonstrates the importance of having an efficient ribosome binding site in the evaluation of promoter function: for example, with this strong ribosome binding site we can show that the wild-type bla promoter is recognized by the B. subtilis transcription machinery.
Mol Gen Genet 1989 Oct
PMID:In vivo selected promoter and ribosome binding site up-mutations: demonstration that the Escherichia coli bla promoter and a Shine-Dalgarno region with low complementarity to the 16 S ribosomal RNA function in Bacillus subtilis. 251 27

Specific in vitro-generated insertion, replacement, and deletion mutations have been integrated near the chromosomal locus of am (NADP-specific glutamate dehydrogenase) of Neurospora crassa. Two approaches have been successful. One approach used am+-containing vectors capable of integrating at any site in the genome. This technique was used to introduce a specific 700 bp insertion near the am locus and to replace chromosomal sequences near am with plasmid DNA. Efficiency was low, however, and many transformants had to be screened to find the desired alterations among the ectopic insertions unless the incoming DNA had a large region of homology with the am region. A second approach increased the efficiency by using vectors containing a truncated am gene, so that prototrophs could arise only by homologous recombination. Overall transformation frequency was reduced relative to the first method, but a large fraction of the transformations involved specific alterations of the am region.
Mol Gen Genet 1989 Jun
PMID:Use of transformation to make targeted sequence alterations at the am (GDH) locus of Neurospora. 254 76

The nucleotide sequence of the Aspergillus nidulans gdhA gene encoding NADP linked glutamate dehydrogenase has been determined and Northern blot analysis used to study the regulation of expression of this gene. The gdhA gene is 1485 nucleotides long and, by comparison with the corresponding Neurospora crassa am gene, has two putative introns of 53 nucleotides and a protein encoding region of 1380 nucleotides that codes for an inferred protein of 49.63 kDa which shows regions of homology with glutamate dehydrogenase proteins from a range of organisms. mRNA analysis of wild-type mycelium grown under a variety of conditions shows that: (a) the highest levels are seen with glucose as the carbon source with inorganic nitrogen; and (b) no gdhA mRNA is detectable when cells are transferred to amino acids as sole carbon source, closely matching the observed glutamate dehydrogenase activity levels under identical conditions. The results presented strongly suggest that a good carbon source is a prerequisite for transcription, but the molecular mechanism responsible is unclear.
Mol Gen Genet 1989 Jul
PMID:Nucleotide sequence and regulation of expression of the Aspergillus nidulans gdhA gene encoding NADP dependent glutamate dehydrogenase. 255 Jul 58

p-Chloromercuribenzoate alters various reactions of rat liver glucose (hexose phosphate) dehydrogenase differently. The reagent has little effect on the glucose: NAD or the glucose: NADP oxidoreductases, doubles the rates of oxidations of galactose-6-phosphate and glucose-6-phosphate by NADP and greatly stimulates the oxidations of glucose-6-phosphate and galactose-6-phosphate by NAD. The reagent appears to react with a sulfhydryl group of the enzyme since activation is reversed and prevented by mercaptoethanol. The direct reaction of the reagent with the enzyme is indicated by its lower thermal stability in the presence of the p-chloromercuribenzoate. The size of the enzyme appears to be the same when determined by sucrose gradient centrifugation in the presence or absence of p-chloromercuribenzoate. In microsomes, the oxidation of NADH or NADPH hampers measurements of glucose dehydrogenase. Since p-chloromercuribenzoate inhibits microsomal oxidation of reduced nicontinamide nucleotides, it is possible to assay for glucose dehydrogenase accurately in the presence of the mercurial in microsomes and microsomal extracts and thus measure the effectiveness of a detergent in extracting the enzyme from microsomes.
Mol Cell Biochem 1989 Apr 11
PMID:The activation of glucose dehydrogenase by p-chloromercuribenzoate. 277 Jul 7

The NADP-dependent glutamate dehydrogenase gene of Klebsiella aerogenes was cloned in E. coli in the expression plasmid pRK9. The cloned gene shows a high level of expression in E. coli in the hybrid plasmid pKG3 and such expression is independent of the vector promoter, as shown by experiments in which the promoter was deleted. Active hybrid GDH hexamers were shown in cell-free extracts of an E. coli strain carrying cloned gdhA genes of both E. coli and K. aerogenes. The nucleotide sequence of the N-terminal coding region of the K. aerogenes gdhA gene was determined and found to be strongly homologous with that of E. coli.
Mol Gen Genet 1985
PMID:The Klebsiella aerogenes glutamate dehydrogenase (gdhA) gene: cloning, high-level expression and hybrid enzyme formation in Escherichia coli. 298 45

The arg-12 locus of Neurospora crassa encodes ornithine carbamoyl transferase, which is one of many amino acid synthetic enzymes whose activity is regulated through cross-pathway (or general) amino acid control. We report here the use of probes derived from the functionally equivalent arg-B gene of Aspergillus nidulans to identify and clone a 10 kb Neurospora DNA fragment carrying the arg-12 gene. Short Neurospora DNA probes derived from this fragment were used to identify a 1.5 kb polyA+ transcript of the arg-12 region. Arg-12 transcript levels increased approximately 20 fold under conditions of arginine or histidine limitation in strains having normal cross-pathway regulation (cpc-1+) but showed no such response in a cpc-1 mutant strain impaired in this regulation. Time course studies in cpc-1+ strains revealed a rapid response (within 10 m) of arg-12 transcript levels following inhibition of histidine synthesis by 3 amino 1,2,4 triazole, but a delayed response following arginine deprivation of an arginine requiring strain. In contrast to the behaviour of arg-12 mRNA, the level of the Neurospora am gene transcript (specifying NADP dependent glutamate dehydrogenase) was unaffected either by amino acid limitation or by the cpc-1 mutation. A possible role for the cpc-1+ product as a positive regulator of transcription of genes subject to cross-pathway control is discussed.
Mol Gen Genet 1986 Apr
PMID:Cloning of the arg-12 gene of Neurospora crassa and regulation of its transcript via cross-pathway amino acid control. 301 77

Glycerol was demonstrated as an end product of anaerobic glucose metabolism in Trichomonas vaginalis and Tritrichomonas foetus, produced in addition to acetate, H2, CO2, and lactate or succinate. In T. vaginalis strain C-1, glycerol amounted to 16% of the fermentation products and was formed at an average rate of 38 nmol min-1 (mg protein)-1. Corresponding figures for T. foetus strain KV1 were 7% and 4.8 nmol min-1 (mg protein)-1. The amounts of glycerol detected compensated almost exactly for the deficits in fermentation products recognized earlier, thus complete redox balances can now be provided for both organisms. The metronidazole-resistant T. foetus strain KV1-1MR-100 excreted only negligible amounts of glycerol and carried out an ethanol-CO2 fermentation. Aerobiosis hardly affected glycerol formation in T. vaginalis strains C-1 and NYH 286, but almost completely abolished it in T. foetus strain KV1. An NADP-dependent glycerol 3-phosphate dehydrogenase and a Mg2+-dependent glycerol 3-phosphatase were detected in the cytosol of both species. The phosphatase is distinct from the particle-bound nonspecific acid phosphatase. Glycerol kinase activity was not detected in either organism. Enhanced pCO2 did not affect the ratio of fermentation products in T. vaginalis strain C-1, but significantly increased the amount of succinate, and decreased the amounts of acetate, H2, and CO2, formed by T. foetus.
Mol Biochem Parasitol 1986 Jul
PMID:Glycerol, a metabolic end product of Trichomonas vaginalis and Tritrichomonas foetus. 301 35

The common approach is developed for isolation of mutants deficient in key enzymes of ribulose monophosphate pathway for formaldehyde oxidation and assimilation by obligate methylotrophic bacteria. The approach is based on total isolation of temperature sensitive mutants and their biochemical characterization. A number of ts- mutants of obligate methylotroph M. flagellatum KT is isolated following nitrosoguanidine induced mutagenesis. The modified screening method was developed and used for identification of mutants deficient in the key enzymes of ribulose monophosphate pathway. The mutant deficient in glucose-6-phosphate dehydrogenase (zwf) was identified. The NAD-dependent activity of glucose-6-phosphate dehydrogenase was not measurable under nonpermissive temperature while the level of NADP-dependent activity was only four-fold less comparing with wild type strain. It was concluded that growth limitation of zwf mutant of M. flagellatum KT (designated T623) at 42 degrees C results from the absence of NAD-dependent activity of glucose-6-phosphate dehydrogenase.
Mol Gen Mikrobiol Virusol 1987 Jul
PMID:[Temperature-sensitive mutant of the obligate methylotroph Methylobacillus flagellatum KT deficient in glucose-6-phosphate dehydrogenase]. 311 3

Malic enzyme catalyzes the NADP-dependent oxidative decarboxylation of malate to pyruvate and carbon dioxide and is involved in lipogenesis. We have investigated the effect of thyroid hormone on the chromatin structure of the malic enzyme gene in rat liver. Hypersensitivity to DNase I in the immediate 5'-flanking region was altered by T3. T3 stimulation induced hypersensitive sites at -310 base pairs (bp) and -50 bp whereas a hypersensitive site at -170 bp was thyroid hormone independent. Hypersensitive sites identified in the 3'-flanking region showed no change with T3 stimulation. We further characterized expression of the malic enzyme gene as a function of thyroidal state by localizing malic enzyme mRNA in hepatocytes using in situ hybridization histochemistry. In hypothyroid and euthyroid states, two populations of hepatocytes were seen, some with malic enzyme message and others with no detectable message. These differences in malic enzyme gene expression were most evident between groups or regions of hepatocytes. After 10 days of thyroid hormone treatment all hepatocytes demonstrated malic enzyme message. The hypersensitivity results confirm that thyroid hormone stimulation of malic enzyme synthesis occurs in part at the level of transcription, and localization of malic enzyme gene expression suggests this stimulation is accompanied by recruitment of hepatocytes. Hepatocytes may be heterogeneous in their ability to respond to thyroid hormone.
Mol Endocrinol 1988 Jul
PMID:The effect of thyroid hormone on the chromatin structure and expression of the malic enzyme gene in hepatocytes. 341 27


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