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 sedimentation characteristics of polysomal mRNA labelled in vitro by [5-3H]uridine and electrophoretic mobility of similar non-labelled mRNA of mouse plasmacytoma were studied. Rapidly labelled polysomal mRNA may be considered as mRNA on the basis of several independent but indirect tests. These mRNA's are localized in 18-6S region of sucrose gradient. Some part of radioactivity have been found in the ribosomal RNA. It was shown that there is 8-10 RNA fractions in sucrose gradient. The 16S and 12-14S fractions are isolated and partially purified by two- and three-fold centrifugation. Fractions homogenous in sucrose gradient were electrophoresed in PAAG-SDS and divided into several subfractions some of them being common for 16S and 12-14S. The number of non-crossover subfractions was about 2-3. Not less than 20 different main fractions of polysomal mRNA were determined in plasmacytoma cells on the basis of electrophoretic data.
Mol Biol (Mosk)
PMID:[mRNA fractions of mouse plasmacytoma cells]. 95 20

The incorporation of [3H]uridine into uterine RNA of immature rats was studied up to 6 h after a single injection of estradiol. Under these experimental conditions, estradiol progressively increased the incorporation of the radioactive precursor into the total RNA. This increase could not be explained by variations in the uptake of [3H]uridine by the tissue. The total RNA and the fractions obtained by differential thermal extraction were analysed by gel electrophoresis. One hour after hormone treatment, a similar increase of incorporation of the labelled precursor in the different RNA species was observed. After a long period of time, [3H]uridine was preferentially incorporated into rRNA as compared to HnRNA and to heterogenous cytoplasmic RNA. Experiments which involved the use of low doses of actinomycin D sufficient to inhibit any rRNA synthesis, confirmed the relatively slight increase in precursor incorporation into non-ribosomal RNA. The distribution of the radioactivity incorporated into the 3 fractions of RNA, obtained by thermal extraction (2 nuclear fractions and 1 cytoplasmic), suggested an increase in the rate of transcription and transport of the RNA during hormonal treatment. The polyA-containing uterine RNA was isolated on a column of oligo(dT)-cellulose and subsequently studied by electrophoresis. There is no preferential incorporation of precursor into the polyA-containing RNA when compared with the total RNA. However, the polyA-containing RNA constitutes the only part of the non-ribosomal RNA whose synthesis continues to increase throughout the period of hormone treatment.
Mol Cell Endocrinol 1976 Dec
PMID:Estrogen-induced changes of ribonucleic acid in the rat uterus. 100 12

1. Glucose 6-phosphate, fructose 6-phosphate, fructose diphosphate, glycerol phosphate and uridine diphosphate glucose have been measured in human adipose tissue and blood from obese subjects under fed and fasting conditions and in obese diabetic and non-diabetic subjects before and after an oral glucose load (100 g). 2. Adipose tissue metabolites expressed as nmol/g wet weight correlated inversely with adipocyte diameter. 3. After fasting, fructose diphosphate and glycerol phosphate in adipose tissue decreased significantly. 4. The basal concentrations of metabolites in blood and adipose tissue were maintained at similar concentrations in diabetic and non-diabetic subjects despite very different blood glucose concentrations. 5. The significant increase in adipose tissue glucose 6-phosphate after the glucose load seen in the non-diabetic but not in the diabetic subjects suggest that glucose uptake is decreased in the diabetic adipocyte.
Clin Sci Mol Med 1975 Jul
PMID:Glucose metabolites in blood and adipose tissue of obese diabetic and non-diabetic subjects. 114 92

Kinetics of incorporation of (3H) uridine into cytoplasmic RNA fractions of rat liver is investigated. The fractions include free and membrane bound polysomes, rough membranes sedimenting with mitochondria and free cytoplasmic RNA particles. (1) Poly(A) containing RNA, isolated by oligo-dT cellulose, amounts to 0.4% of the total RNA in the homogenate, 0.5% in bound polysomes, 3.4% in free polysomes and 16% in free cytoplasmic RNA particles. (2) The rate of (3H) uridine incorporation into RNA lacking poly(A) proceeds uniformly in all subcellular fractions except for free cytoplasmic RNA particles, which accumulate negligible amounts of radioactivity. (3) The initial labelling of RNA containing poly(A) is most active in free cytoplasmic RNA particles supporting their identity as mRNA en route to polysomes. The initial specific radioactivities decrease in the following order: homogenate, bound polysomes, rough membranes sedimenting with mitochondria, free polysomes. The data suggest that mRNA is supplied to free and membrane-bound polysomes via different routes. The kinetic analysis indicates that free cytoplasmic RNA particles may be a precursor of mRNA of free polysomes rather than that of bound polysomes. (4) The kinetic differences of free and membrane bound polysomes are also demonstrated by comparing the radioactivity of RNA containing poly(A) to the total radioactivity at various incorporation times. In bound polysomes this decreases from 31% at 1 h to 10% at 25 h, whereas in free polysomes the corresponding ratio increases from 10 to 13%. RNA containing poly(A) of free cytoplasmic RNA particles represents 64% of the total radioactivity throughout the experiment.
Mol Cell Biochem 1975 Aug 30
PMID:Labelling kinetics of RNA containg poly(A) in liver subcellular fractions. 116 64

The primary structure of tRNAVal2a from baker's yeast has been determined. The general methods of the investigation are presented. Twenty six distinguished points can be noted in the tRNAVal2a and tRNA1Val from baker's yeast. The anticodon region of tRNAVal2a is represented by the sequence NAC, where N corresponds to a uridine analogue nucleoside of unknown structure. The comparison of primary structures of tRNAVal2a, tRNAVal2a, tRNA1Val from E. coli and tRNAVal2a and tRNA1Val from baker's yeast is analysed.
Mol Biol (Mosk)
PMID:[The primary structure of tRNA Val 2a from baker's yeast]. 121 73

Incorporation of [3H] uridine into the ribonucleoside triphosphates UTP and CTP, total RNA, and nuclear and cytoplasmic RNA was followed in Xenopus laevis tadpole liver during thyroxine (T4)-induced metamorphosis. Pool sizes of UTP and CTP were found to remain unchanged, although turnover the ribonucleoside triphosphates was found to be greatly stimulated after 4 days of hormone treatment. The time course of labeling of the 40-S pre-rRNA was very similar to that of UTP in both thyreostatic and T4-treated tadpoles, thus reflecting a direct relationship between turnover of the immediate precursors and labeling of RNA. Although a faster depletion of labeled UTP and pre-rRNA (precursor ribosomal RNA) was noted in T4-treated tadpoles, labeled cytoplasmic rRNA continued to accumulate almost linearly for 25 h. In thyreostatic larvae no further increase in labeled cytoplasmic rRNA occurred beyond 4 h of labeling. From these results we conclude that both enhanced transcription and more effective utilization of pre-rRNA are responsible for the net accumulation of rRNA observed on the 4th day of T4-induced metamorphosis.
Mol Cell Endocrinol 1976 Jan
PMID:Incorporation of (5-3H) uridine into ribonucleotide pools and RNA during thyroxine-induced metamorphosis of Xenopus laevis tadpoles. 124 66

The synthesis of virus-specific macromolecules was studied in the reconstituted system containing inner membrane-matrix fraction from rat liver mitochondria and infectious RNA of Venezuelian equine encephalomyelitis (VEE) virus. In a series of preliminary experiments it was shown that isolated submitochondrial fraction was completely free of interfering cytoplasmic contaminations and particularly, of cytoplasmic 80S ribosomes. VEE RNA when added to submitochondrial system caused significant stimulation of RNA and protein synthesis. These processes were resistant to actinomycin D which inhibited profoundly the synthesis of proper mitochondrial macromolecules. The stimulating effect of VEE RNA in experiments with submitochondrial system was about three times higher than that with intact mitochondria. The stimulation of 14C-amino acid incorporation increased as a function of incubation time; a certain lag-period being observed. The newly formed virus-specific RNA's and ribonucleoproteins were identified with the aid of sedimentation analysis. In particular, radioactive RNA's with sedimentation coefficients 40S and 26-18S were isolated from the incubated system. These RNA's are similar respectively to VEE genome RNA and double-stranded VEE replicative RNA. In double labelling experiments with 3H-uridine and 14C-amino acids it was shown that VEE RNA induced synthesis of ribonucleoproteins containing newly formed RNA and protein. These RNP possessed sedimentation coefficients 60-80S, 140S and 300S in sucrose gradient and buoyant densities 1.32 and 1.50 g/cm3 in cesium chloride gradients. These properties of ribonucleoproteins synthesized de novo in submitochondrial system are close to those of RNP intermediates of VEE virus reproduction in the infected cells. We concluded that viral RNA could program virus-specific synthesis in the submitochondrial system under conditions that eliminated the contribution of cytoplasmic ribosomes.
Mol Cell Biochem 1976 Jan 31
PMID:On the synthesis of viral ribonucleic acids and ribonucleoproteins in the submitochondrial system completely free of interfering cytoplasmic contaminations. 125 Feb 22

With the aim of determining the distribution of the incorporation of 3H-uridine in both retina and retinal pigment epithelium (RPE), the mouse eyes at embryonic day 9.5 (E 9.5), E 12.5, E 14.5, E 16.5, E 18.5 of gestational ages, and postnatal day 1 (P 1), P 3, P 7, P 14 were analyzed by light microscopic radioautography. Small pieces of the ocular tissues were labelled with 3H-uridine in vitro and light microscopic radioautographs were prepared. The average grain numbers per cell of the respective regions of tissues were calculated. In the retina, the grain numbers increased gradually from E 9.5 to P 1 and reached the maximal value at P 1, and then decreased until P 14. However, the grain numbers were more in the vitreal portion than those in the scleral portion at E 16.5 and then became more in the scleral portion from E 18.5 to P 14. It is considered that the ganglion and bipolar cells finish the RNA synthesis earlier, while the photoreceptor cells do it later during the fetal and postnatal development. In the RPE, the grain numbers gradually increased from E 12.5 to P 7 and then decreased until P 14. Considering the same ages, the grain numbers increased in the following order, anterior, equatorial and posterior regions during embryonic stages, but decreased in the same order after birth. Therefore, it is suggested that the activity of RNA synthesis in PE cells is higher in the posterior region than in the anterior region during embryonic stages. But the activity ascends generally and becomes relatively higher in the anterior region, after birth. Comparing the retina and RPE, it was noted that the grain numbers in the RPE were more important than in the retina and that the maximal value was at P 1 in the retina, while it was at P 7 in the RPE. From these results, it can be concluded that the RNA synthesis ceases earlier in the retina than in the RPE.
Cell Mol Biol (Noisy-le-grand)
PMID:Study on RNA synthesis in the retina and retinal pigment epithelium of mice by light microscopic radioautography. 128 49

We have previously reported the isolation and characterization of mutant Chinese hamster ovary (CHO-K1) cells of the Urd-A complementation group, which require uridine for growth, are deficient in the activities of the first three enzymes of de novo UMP biosynthesis, and produce markedly reduced amounts of a truncated form of the multifunctional protein CAD, which contains these three enzyme activities. We report here that a single base change of G to A at a highly conserved RNA splice acceptor site is responsible for the phenotype of this mutant. In addition to a small amount of apparently normal CAD mRNA, this mutation causes production of two alternative forms of CAD mRNA in the mutant, one that includes the intron just prior to the mutation and one that excludes the exon just after the mutation. The affected splice site is located at the intron-exon boundary just preceding the exon that encodes the beginning of the aspartate transcarbamylase (ATCase) domain of the CAD protein. Both intron inclusion and exon exclusion during RNA processing introduce a translation stop codon upstream of the region encoding this domain, resulting in the production of the truncated CAD protein seen in the Urd-A mutant. This mutation also results in markedly decreased levels of CAD mRNA and protein in the mutant.
Somat Cell Mol Genet 1992 Jan
PMID:A single base change at a splice acceptor site leads to a truncated CAD protein in Urd-A mutant Chinese hamster ovary cells. 134 64

Rho-independent terminators are characterized by two major functional regions, one upstream from the termination site having a sequence capable of forming an RNA hairpin in the nascent transcript, the second extending, from the base of this hairpin, seven to nine nucleotides along the transcript to the actual sites of termination (3'-tail region). This latter region of the transcript is often rich in uridine residues. Both regions are postulated to play central roles in the termination process. We have constructed a series of hybrid rho-independent, transcription terminators in which sequences upstream and downstream from the RNA hairpin for the Escherichia coli trp attenuator (trpatt+) are interchanged with sequences from trpatt mutant (1419) or from the phage T7 early terminator (T7Te). Similar hybrids have been constructed for T7Te, replacing flanking sequences with trpatt regions. The effects of such changes on transcription termination have been tested in vitro with purified E. coli RNA polymerase to determine the intrinsic termination efficiency (%T) of each hybrid terminator. Both the trpatt+ terminator and T7Te are highly efficient rho-independent terminators in vitro. However, replacement of trpatt+ sequences upstream and downstream from the RNA-terminator hairpin with the comparable T7Te sequences reduces %T dramatically, suggesting that the RNA-terminator hairpin does not function independently from its flanking regions. Regions downstream from the actual termination/release site are shown to be of considerable importance in determining %T for terminators bearing the T7Te or trpatt1419 3'-tail region, but have little effect on terminators with the trpatt+ 3'-tail region. For terminators bearing the T7Te or trpatt1419 3'-tail region that are inefficient, efficient termination is restored by elevated concentrations of KCl in the reaction. The results do not fit well with models for termination in which %T is determined by a two-step process in which the terminator-RNA hairpin, and a seven to 12 base-pair DNA-RNA hybrid structure rich in uridine residues, act independently to cause the polymerase to pause, and to release the transcript, respectively. DNA sequences both upstream and downstream from these regions, as well as DNA sequences downstream from the transcript termination site, can significantly affect the termination process. Conversely, terminators lacking a 3'-tail region rich in uridine residues can be highly efficient, but only when joined with appropriate sequence immediately downstream from the termination site. This suggests that the 3'-tail region acts in some manner other than the formation of an unstable DNA-RNA hybrid that facilitates termination.
J Mol Biol 1992 Mar 05
PMID:Parameters affecting transcription termination by Escherichia coli RNA. II. Construction and analysis of hybrid terminators. 137 66


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