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)

AraC protein from Escherichia coli has been further stabilized and characterized. pH is a critical variable in conferring stability. araC protein has a sedimentation coefficient of 4.0 +/- 0.2s on standardized 5%-20% glycerol gradients. Its isoelectric point is at a pH of 7.1.
Mol Gen Genet 1976 Apr 23
PMID:Stabilization and size of araC protein. 77 15

An E. coli lysate after being gently washed to remove soluble components, supports replicative DNA synthesis, if soluble proteins and the deoxyribonucleotide triphosphates are added. This DNA synthesis is dependent on ATP and on the presence of the gene products of the dnaB, dnaG, and polC (DNA polymerase III) genes. It continues at the replication forks preformed in vivo and "Okazaki fragments" are intermediate products of the reaction. Two different methods were used to prepare the washed DNA containing fraction. The one method involves washing of a cell lysate situated on a dialysis membrane. The other method involves DNAase treatment of a lysate and sedimentation of the degraded DNA through a glycerol gradient. Both washed preparation contain not only the DNA and the replication forks but also functional amounts of DNA polymerase III and of the dnaB gene product. Other factors, that are essential for replicative DNA synthesis, including the dnaG gene product, are washed out of the DNA containing preparations and the system is reconstituted by readdition of the soluble proteins.
Mol Gen Genet 1976 May 07
PMID:Replication of E. coli duplex DNA in vitro. The separation of the DNA containing fractions of a lysate from the soluble enzymes and their complementation properties. 77 84

RNA polymerase isolated from ts XH56, a conditional lethal mutant unable to grow and synthesize RNA at 42 degrees, was found to be temperature sensitive in vitro. The mutation affects the beta' subunit as determined by mixed reconstitution of isolated subunits from wild-type and mutant enzyme. The mutant RNA polymerase is unstable; addition of glycerol stabilizes the enzyme and increases its activity on native DNA. In addition, the mutant enzymes is sensitive to high ionic strength. Both high temperature and high ionic strength do not affect chain elongation; thus, the mutation renders the enzyme unable either to bind to or melt out promotor sites. From these data we conclude that the beta' subunit plays an important role in promotor selection.
Mol Gen Genet 1976 Sep 23
PMID:Characterization of a ts beta' mutant RNA polymerase of Escherichia coli. 78 68

A mutant of Saccharomyces cerevisiae has been isolated which, though exhibiting a normal response to nuclear genetic damage by ultraviolet light (UV), is more sensitive than its wild type specifically in the production of the cytoplasmic (rho-) mutation by this agent. Some of the features of this mutation which has been designated uvsrho 5 are: i) The mutation is recessive, it exhibits a Mendelian, and hence presumably nuclear, pattern of segregation, but manifests its effects specifically and pleiotropically on mitochondrial functions. ii) Mutant cells resemble their wild type parents in a) growth characteristics on glucose; b) in their UV induced dose response to lethality or nuclear mutation and c) the ability of their mitochondrial genome, upon mating with appropriate testers, of transmitting and recombining various markers, albeit with enhanced efficiency. Similarly, d) they are able to modulate the expression of mitochondrial mutagenesis by ethidium bromide. Thus their mitochondrial DNA appears genetically as competent as that of the wild type. iii) Mutant cells differ from their wild type parents in a) growth characteristics on glycerol; b) susceptibility to induction of the mitochondrial (rho-) mutation by various mutagens, in that the rate of spontaneous mutation is slightly and that by UV is significantly enhanced, whild that by ethidium bromide is greatly diminished. Conversely, c) modulating influences resulting in the repair of initial damage are diminished fro UV and stimulated in the case of Berenil. iv) The amount of mitochondrial DNA per cell appears elevated in the mutant, relative to wild type, and its rate of degradation subsequent to a mutagenic exposure to either UV or ethidium bromide is diminished. v) A self-consistent scheme to account for this and all other information so far available for the induction and modulation of the (rho-) mutation is presented. In a previous study it was shown that some nuclear mutants of Saccharomyces cerevisiae, more sensitive to lethal damage induced by ultraviolet light (rad) than their parent wild type (RAD), also exhibit a concomitant modification in sensitivity to both nuclear and cytoplasmic genetic damage (Moustacchi, 1971). However, another class of rad mutants respond to the induction of the cytoplasmic "petite" also designated as rho- (or rho-) mutation by UV in a manner indistinguishable from that of the RAD strain. One possible interpretation of this last observation is that some of the steps in the expression of the UV damage on mitochondrial (mt)DNA may be governed by other nuclear and cytoplasmic genetic determinants, the products of which may then act specifically on mitochondrial lesions. If this assumption is correct, it should be possible to find mutants with a normal response to nuclear damage but specifically UV-sensitive towards induction of (rho-)...
Mol Gen Genet 1976 Nov 17
PMID:A novel class of Saccharomyces cerevisiae mutants specifically UV-sensitive to "petite" induction. 79 62

Mutants defective in polyol metabolism and/or in protoperithecial development were selected in Neurospora tetrasperma, a species in which protoperithecial development occurs at nonpermissively high temperature if certain polyols are used in lieu of sucrose as carbon source. Mutants selected for nonutilization of one of the four polyols tested, glycerol, mannitol, sorbitol, or xylitol, were usually found to be nonutilizers of the other three polyols as well. Mutants blocked at various stages of protoperithecial development complemented pairwise to produce more advanced developmental stages, usually mature protoperithecia and, when of opposite mating type, mature perithecia. About one-third of the mutants manifested both polyol auxotrophy and defective protoperithecial development upon initial isolation, but protoperithecial defectiveness in such mutants usually showed erratic segregation in crosses and/or instability to repeated vegetative transfer, whereas polyol auxotrophy usually did not and was, therefore, studied further. Two glycerol nonutilizing strains were introgressed into N. crassa to facilitate genetic analysis. One, glp-4, lacked both inducible and constitutive glycerol kinase and mapped to linkage group VI, between ad-1 and rib-1; the other, glp-5, lacked glyceraldehyde kinase and mapped to linkage group I, proximal to ad-9. Another mutant, gly-u(234), has been reported by other investigators to lack inducible glycerol kinase but to map to linkage group I, distal to ad-9.
Mol Gen Genet 1977 May 20
PMID:Characterization of glycerol nonutilizing and protoperithecial mutants of Neurospora. 88 70

1. The mechanism whereby p-chlorophenoxyisobutyrate (CPIB) lowers plasma non-esterified fatty acid concentrations has been studied in dogs by measuring the associated changes in adipose tissue metabolism. 2. CPIB lowered arterial concentrations of non-esterified fatty acids during isoprenaline infusion by a mean value of 41%. 3. This was accompanied by a proportionate decrease (45%) in the release of non-esterified fatty acids from subcutaneous adipose tissue in situ, and by a lesser reduction (22%) in than of glycerol. 4. Adipose tissue blood flow was unchanged by CPIB. 5. These findings indicate that the lowering effect of CPIB on non-esterified fatty acid concentrations derives principally from decreased mobilization rather than from increased tissue uptake of the fatty acids, and that this reflects both inhibited lipolysis and enhanced re-esterification of the fatty acids in adipose tissue.
Clin Sci Mol Med 1976 Jul
PMID:Effects of p-chlorophenoxyisobutyrate on free fatty acid mobilization from canine subcutaneous adipose tissue in situ. 93 61

1. From different studies on the cellular localization, postional specificity, and regulatory properties of acyl-CoA: glycerophosphate acyltransferase (EC 2,3,1.15) AND ACYL-CoA: 1-ACYLGLYCEROPHOSPHATE ACYLTRANSFERASE (EC 2,3,1....) the following conclusions can be drawn: The glycerophosphate acyltransferase is localized in the endoplasmatic reticulum (microsomes) and in the outer membrane of the mitochondria of the animal cell. Its reaction product is 1-acylglycerophosphate (1-lysophosphatidic acid). The mitochondrial enzyme shows a high preference for saturated fatty acids while the microsomal enzyme is less specific (alternatively the microsomes contain more than one glycerophsophate acyltransferase). 2. The 1-acylglycerphosphate acyltransferase is localized in the endoplasmatic reticulum (microsomes) in the animal cell. Possibly a minor fraction of this enzyme is localized to the outer membrane of the mitochondria. This enzyme shows a strong preference for unsaturated fatty acids. 3. Both the microsomal and the mitochondrial dihydroxyacetonephosphate acyltransferase show similar fatty acid specificity as the corresponding glycerophosphate acyltransferases. It cannot be excluded that dihydroxy-acetonephosphate and glycerophosphate are acylated by the same enzymes. 4. The activity of the glycerophosphate acyltransferase(s) in the liver decreases in fasting or fat feeding and increases upon feeding of carbohydrate. The activity of carnitine palmityltransferase varies exacty opposit. These enzymes do not show dietary variations in heart and adipose tissue. 5. Under the otherwise identical conditions the rate of carnitine acylation in isolated mitochondria decreases more than the rate of glycerophosphate acylation when the concentration of palmityl-CoA is reduced. 6. In isolated liver cells (which has lost most of their carnitine) addition of carnitine increases the rate of fatty acid oxidation and decreases the rate of triglyceride formation. 7. Glycerol and fructose lower the rate of fatty acid oxidation, probably by lowering the levels of acyl-CoA and acyl-carnitine in the cells. 8. It is concluded that the relative activities of glycerophosphate acyltranse and carnitine palmityltransferase probably influence the fate of fatty acids in the cell.
Mol Cell Biochem 1976 Aug 30
PMID:The glycerophosphateacyltransferases and their function in the metabolism of fatty acids. 95 14

By measuring the specific radioactivity of glucose released from isolated perfused livers of normal, fed rats in the presence of [U-14C]fructose, the gluconeogenetic and glycogenolytic contributions to glucose production were estimated. After 20 min of perfusion with 4 mM fructose, glycogenolysis was inhibited by 40% in the absence and by 70% in the presence of glucagon (3 nM). Glucagon decreased the release of lactate plus pyruvate and enhanced glucose formation from fructose without affecting its uptake. Glycerol (4 mM) and xylitol (3 mM) had qualitatively similar, but smaller effects on glucagon-stimulated glycogenolysis. The glucagon-mediated phosphorylase b to a conversion was not altered by fructose, indicating that glycogenolysis was decreased as a consequence of an inhibition of phosphorylase a. During the first minutes after the addition of fructose, decreased ATP/AMP ratios and tissue Pi levels correlated with a transient increase of phosphorylase a activity. It was concluded that the effects of fructose on the control of hepatic glycogenolysis and glucose production were the result of a complex interplay between a transient b to a conversion of phosphorylase and an inhibition of the a-form of the enzyme, possibly by fructose 1-phosphate and other phosphorylated metabolites.
Mol Cell Endocrinol 1976 Nov
PMID:Interactions of glucagon and fructose in the control of glycogenolysis in perfused rat liver. 100 7

A rapid method suitable for purifying large amounts of mitochondria from rat liver using isopycnic zonal centrifugation is described. The RNA polymerase isolated from the purified mitochrondria was found associated with one peak when resolved by DEAE Sephadex chromatography. The enzyme was next fractionated on a phosphocellulose column followed by glycerol gradient centrifugation. A 600-fold purification was achieved when the enzyme was finally filtered through agarose gel. This final enzyme fraction consisted of one polypeptide chain as shown by polyacrylamide gel electrophoresis profiles. The enzyme has a greater preference for poly [d(A-T)] templates than for rat liver mitochondrial DNA. Inhibition of the enzyme activity required high concentrations of the inhibitors. The resistance of the enzyme to alpha-amanitin indicated that there was no contamination from nuclear RNA polymerase II. The conclusion is drawn that the mitochondrial RAN polymerase activity is associated with a single polypeptide.
Mol Cell Biochem 1976 Dec 10
PMID:Some properties of rat liver mitochondrial RNA polymerase. 100 1

1. Acute renal failure was produced in rats by intramuscular injection of glycerol. Subsequently, changes in the concentrations of renin and of angiotensin II in plasma and the renin content of the kidneys were followed. 2. at 4 and 8 h after glycerol administration, plasma renin and angiotensin II had increased two to three-fold; they remained elevated for 48 h and then returned towards normal. At 7 days, the values were still slightly raised. 3. At 4 and 8 h after glycerol injection, kidney renin had decreased but it had increased after 24 and 48 h. 4. Passive immunization with angiotensin II antibodies, given at the time of glycerol injection and 2 and 4 h afterwards, prevented the development of acute renal failure. When angiotensin II antiserum was administered later (8, 10 and 12 h after glycerol) it had no effect. 5. Stimulation of the renin-angiotensin system may be involved in the pathogenesis of the early phase of acute renal failure.
Clin Sci Mol Med Suppl 1975 Jun
PMID:The renin-angiotensin system in acute renal failure of rats. 105 77


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