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)

The simultaneity of the presence of substrate (inducer) and the absence of a better nitrogen nutrient causes a strong cooperative effect (catabolic synergism) on arginase production. This effect is shown to operate by a specific mechanism. carg A+ 0h mutation (Dubois et al., 1978) identifies an element of this process located near the arginase structural gene and acting in cis. This mutation produces constitutivity for synergism in addition to constitutivity for induction (this last effect is produced alone by cargA +0- operator constitutive mutation). The receptor of the signal for the presence of substrate is the same as for induction. cargA + 0h mutation allows to make further distinction between the promotion of arginase synthesis caused by nitrogen limitation and nitrogen starvation.
Mol Gen Genet 1978 Sep 08
PMID:Catabolic synergism: a cooperation between the availability of substrate and the need for nitrogen in the regulation of arginine catabolism in Saccharomyces cerevisiae. 36 56

A derivative of an areA200 strain of Aspergillus nidulans selected for strong growth on acetamide as the sole nitrogen source was found to have a mutation, amd-18, closely linked to amdS, the acetamidase structural gene. This mutation results in 2--3 fold higher acetamidase activities than wildtype strains in uninduced as well as induced cultures. The effects of the amd-18 mutation are superimposed on the effects of other regulatory mutations affecting the acetamidase. The amd-18 mutation is cis-dominant with respect to the amdS gene. Immunological and gel electrophoresis studies have shown that amd-18 strains produce higher levels of acetamidase protein. A previously described cis-dominant mutation, amdI9, also causes elevated levels of acetamidase protein. The amd-18 mutation may affect a promoter site for the amdS gene allowing an increased frequency of transcription.
Mol Gen Genet 1978 Oct 25
PMID:An "up-promotor" mutation affecting the acetamidase of Aspergillus nidulans. 36 68

The peptide-chain elongation rate of Saccharomyces cerevisiae at two different growth rates was estimated by the kinetics of radioactive labelling of nascent and finished polypeptides as described by Gausing, 1972, and Young and Bremer, 1976. The elongation rates of a diploid strain cultured in yeast nitrogen base supplemented with glucose or acetate were 9.3 amino acids/s and 5.5 amino acids/s at 30 degrees C, respectively. These data together with published values on the "ribosomal efficency" as a function of growth rate (Waldron and Lacroute, (1975) enable us to estimate the rate of synthesis of ribosomal proteins as a function of the rate of total protein synthesis, alpha r, and the fraction of ribosomes that one active in protein synthesis. We conclude that in S. cerevisiae alpha r is largely independent of the growth rate while the fraction of active ribosomes decreases with decreasing growth rate.
Mol Gen Genet 1979 Feb 26
PMID:Peptide chain elongation rate and ribosomal activity in Saccharomyces cerevisiae as a function of the growth rate. 2787 2

In Aspergillus nidulans expression of the gabA gene, the probable structural gene for the gamma-amino-n-butyrate (GABA) permease, is controlled by induction, via the intA gene, ammonium repression, mediated by the areA gene, and probably carbon catabolite repression. Regulatory mutations, tightly linked to gabA, were selected by reverting an areAr-2 strain on GABA as nitrogen source. These mutations, gabI-1, gabI-2, and gabI-3 result in increased gabA expression and are cis-dominant in their effects on the gabA gene. Mapping data show that the regulatory mutations map on one side of all gabA- alleles tested.
Mol Gen Genet 1979 Jan 16
PMID:Cis-dominant regulatory mutations affecting the expression of GABA permease in Aspergillus nidulans. 37 1

The levels of glucose-6-phosphate and 6-phosphogluconate dehydrogenase in wildtype cells of Aspergillus nidulans varied with the carbon and nitrogen source. In general, hexokinase activity did not vary with carbon or nitrogen source. The ammonium derepressed mutant amrA1 had only 50% of the wildtype level of hexokinase. Phosphoglucomutase activity was low in wildtype cells grown with nitrate, but high in cells grown with ammonium when glucose was the carbon source. A non-inducible mutant, nirA-1, in the regulatory gene for nitrate reductase, had high phosphoglucomutase activity when grown with nitrate or ammonium. A constitutive mutant nirAc1, in the regulatory gene for nitrate reductase had low phosphoglucomutase activity when grown with nitrate or ammonium. The mutants nir-1 and nirAc1 are recessive and semi-dominant respectively for abnormal phosphoglucomutase activity.
Mol Gen Genet 1979 Mar 09
PMID:The regulation of hexokinase and phosphoglucomutase activity in Aspergillus nidulans. 37 22

A study has been made of the regulation of the synthesis of Pl double-stranded (ds) RNA, the genome of the yeast virus-like particle. When yeast protein synthesis is prevented by starvation for a required amino acid or by addition of cycloheximide, the rate of Pl dsRNA synthesis is reduced markedly. During nitrogen starvation the synthesis of Pl dsRNA persists but is accompanied by the degradation of pre-existing molecules. This degradation appears to require the induction of new enzymes and it is likely that the breakdown products are used to enable the cell to complete its division cycle. However, all of the copies of the VLP genome are not degraded in this process, some are conserved and can replenish the amount of Pl dsRNA on return to growth conditions. The controls which must operate on Pl dsRNA synthesis are discussed and compared with those exerted on nuclear RNA synthesis in yeast.
Mol Gen Genet 1979 Mar 20
PMID:The regulation of RNA synthesis in yeast IV. Synthesis of double-stranded RNA. 37 28

A method to detect low levels of interstrand cross-links in DNA of Saccharomyces cerevisiae is described. Isopycnic ultracentrifugation of alkali-treated, unpurified Eaton press homogenates allows the detection of less than one cross-link per yeast chromosome. Efficient separation of single- and double-stranded DNA requires low cell density and addition of glycerol during homogenization. Using a yeast strain defective in excision repair, a dose dependent formation of interstrand cross-links after treatment of cells with biological doses of nitrogen mustard, Triaziquone and Chloramubil could be demonstrated. The most powerful of these alkylating agents is Triziquone: half of the DNA molecules are shown to be cross-linked after a 12 min exposure to 9 X 10(-9) g/ml of the drug. The cross-linking reaction continues after excessive alkylating agent is removed. After having reached a maximum the fraction of renaturable DNA decreases upon further incubation. The speed of this "after-reaction" depends on temperature: 48 h after the end of treatment renaturability of DNA has almost completely disappeared when cells are kept at 36 degrees C.
Mol Gen Genet 1979 Oct 02
PMID:Formation and fate of cross-links induced by polyfunctional anticancer drugs in yeast. 39 49

1. Rates of total protein turnover, synthesis and breakdown were measured in five children before and after recovery from severe protein-energy malnutrition and while receiving 0.6 g of protein and 397 kJ day-1 kg-1. 2. Thes rates were calculated after giving doses of [15N]glycine every 2 h along with the feeds and measuring the rate of excretion of [15N]urea in urine. 3. Malnourished children had significantly lower rates of protein turnover, synthesis and breakdown than after they had recovered. 4. During recovery from protein-energy malnutrition, two children on a daily intake of 1.2 g of protein and 605 J/kg body weight, had rates of protein turnover, synthesis and breakdown that were twice as great as those found on admission and higher than after recovery. 5. On the study diet the malnourished children maintained their weight while the recovered children lost weight; the apparent nitrogen balance was more positive in the malnourished children. 6. In recovered children, the rate of protein synthesis was unchanged over a wide range of protein intake, whereas the rate of protein breakdown appeared to rise with a reduction in protein intake.
Clin Sci Mol Med 1977 Nov
PMID:Protein turnover, synthesis and breakdown before and after recovery from protein-energy malnutrition. 41 38

Two sheep with a ruminal fistula and an isolated small rumen were studied for the secretion of ammonia nitrogen, urea nitrogen, and amino nitrogen into the isolated rumen at different levels of volatile fatty acids (VFA) (50, 133-97, and 97-66 M Mol 1(-1)) in the rumen. The VFA level in the rumen was found to exert a great influence on the quantitative secretion of endogenous nitrogen from the blood through the rumen wall into rumen content. When the VFA level in the rumen was increased by administration of a single dose of acetic, propionic, and butyric acid, the secretion of ammonia nitrogen and amino nitrogen abruptly dropped and the secretion of urea into the isolated rumen slightly increased. The over-all amount of nitrogen (NH3-N + urea-N + amino-N) that had passed into the isolated rumen in the course of an hour showed a highly significant correlation with the passage of nitrogen in the form of ammonia and amino nitrogen and was greatest before the application of VFA to the rumen, i.e. at the level of 50 m mol 1-1. Of the metabolites under study, which were passing to the isolated rumen, amino nitrogen shared the greatest proportion (45.38-46.54%). When the VFA level in the rumen was raised, the proportion of ammonia secreted to the isolated rumen decreased and the proportion of urea in the total amount of nitrogen increased.
 ...
PMID:[Relationship between the volatile fatty acids (VFA) in the rumen and nitrogen secretion into isolated sheep's rumen]. 41 43

1. Total-body neutron-activation analysis in vivo was carried out in 11 hypertensive subjects to measure simultaneously the total body content of sodium, chlorine, calcium, phosphorus and nitrogen. 2. There was a highly significant correlation between total body sodium measured by activation analysis and total exchangeable sodium measured by a standard isotope-dilution technique (r = 0.92, P less than 0.001). Exchangeable sodium averaged 80.3% of total body sodium. 3. The measured values of chlorine, calcium, phosphorus and nitrogen were similar to those for healthy subjects reported by others. 4. Activation analysis in vivo appears promising as an additional tool for investigating sodium metabolism in hypertension, as it is the only method available for determining the total body content of this element. The radiation dose (1 rem) is sufficiently low to permit repeated measurements in the same subject.
Clin Sci Mol Med 1978 Feb
PMID:Concurrent estimation of total body and exchangeable body sodium in hypertension. 41 89


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