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X Xu

Publications and source records attributed to X Xu.

At least 955 records · Page 53Linked to original sources
PubMed1994

Comparison of effects of margarite extract and recombinant human superoxide dismutase on paraquat-induced superoxide anion radicals in rat lung.

The effects of medicinal margarite extract and recombinant human superoxide dismutase (r-h SOD) on acute paraquat intoxication were examined in the rat lung. Forty-eight Sprague-Dawley rats under pentobarbital anesthesia were randomly assigned to one of four groups receiving i.v. injection of physiological saline (control), i.v. injection of 70 mg/kg paraquat, or i.v. injection of either 50 mg/kg of margarite extract or 50,000 unit/kg of r-h SOD 10 minutes before and 1 and 2 hours after an equivalent paraquat administration. Examination of lung superoxide anion radicals (O2-.), lipid peroxides, and histopathological changes showed that paraquat significantly increased superoxide anion radicals (383% of control) reacted with CLA-phenyl. Both margarite extract and r-h SOD decreased superoxide anion radicals to 119% and 83% of control, respectively. Margarite extract, rather than r-h SOD, significantly alleviated the paraquat-induced infiltration of polymorphonuclear leukocytes and macrophages into the alveolar walls. There were no significant inter-group differences in lipid peroxides in the lung. Component analysis showed that margarite extract was rich in L- and D-arginine. The scavenging mechanism of margarite extract may be related to L-arginine but needs to be further verified in the future study.

Animals↗
PubMed1994

Smoking, changes in smoking habits, and rate of decline in FEV1: new insight into gender differences.

We wanted to test the hypothesis that gender differences in effects of smoking on the rate of decline in pulmonary function may be related to gender differences in the frequency of smoking. Data from the Vlagtwedde-Vlaardingen study in The Netherlands were analysed, to investigate the rate of decline in forced expiratory volume in one second (delta FEV1) in relation to smoking status and gender. 4,554 participants, initially aged 15-54 yrs, provided 16,900 pairs of observations at 3 yr intervals over 24 yrs of follow-up. Lifetime nonsmokers accounted for 11% of male participants and 45% of female participants. Compared with lifetime nonsmokers, estimated excess delta FEV1 for light, moderate, and heavy continued smokers was 4.4, 9.5 and 13.5 ml.yr-1 for men and 6.1, 10.8 and 18.8 ml.yr-1 for women, respectively. Female former smokers had a significantly more rapid delta FEV1 (beta = 4.4, SE = 1.6 ml.yr-1) than lifetime nonsmokers; but male former smokers had a slower rate of decline (beta = 4.1, SE = 2.3 ml.yr-1) than lifetime nonsmokers. Overall gender difference in smoking effects on delta FEV1 was statistically significant. Among subjects who smoked an identical amount at the beginning of the study period those who quit smoking during the period had a significantly slower delta FEV1 than those who continued smoking, for both men (beta = 20.6, SE = 3.9 ml.yr-1) and women (beta = 15.7, SE = 3.4 ml.yr-1). Younger quitters (< 45 yrs) benefited significantly more from smoking cessation than older quitters (> or = 45 yrs).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Modulation of three types of K+ currents in canine coronary artery smooth muscle cells by NS-004, or 1-(2'-hydroxy-5'-chlorophenyl)-5-trifluoromethyl-2(3H) benzimidazolone.

The effects of the cardioprotective, vasorelaxant agent NS-004 [1-(2'-hydroxy-5'-chlorophenyl)-5-trifluoromethyl-2(3H) benzimidazolone] on K+ currents of freshly isolated canine coronary artery smooth muscle cells were examined using the suction pipette method. The Ca(++)-sensitive K+ current (IK, Ca) was isolated by using a holding potential of 0 mV and 5 mM ATP in the internal perfusate. The voltage-dependent delayed rectifier K+ current (IK, DR) was recorded at potentials below 20 mV in internal solution containing 5 mM ATP. The ATP-sensitive K+ current (IK, ATP) was induced by removing ATP in the pipette solution and was measured at potentials negative to -30 mV where IK, Ca and IK, DR were absent. External application of NS-004 activated IK, Ca, which, at 80 mV, was increased from 0.28 +/- 0.03 to 1.1 +/- 0.2, to 3.2 +/- 1.0, to 5.6 +/- 1.6 and to 8.5 +/- 1.6 nA, respectively, by 12.5, 25, 50 and 100 microM NS-004. Structurally related flufenamic, niflumic and mefenamic acids, at 100 microM, also enhanced IK, Ca. The order of potency for IK, Ca activation was NS-004 >> flufenamic = niflumic > mefenamic. In contrast, NS-004 blocked IK, DR, beginning at 2 microM with 50% inhibition at 22 microM. NS-004 also inhibited IK, ATP with a Ki value of 2.4 microM and a Hill coefficient of 1.3 in 0 mM intracellular ATP. These results demonstrate that NS-004 is a more potent activator of IK, Ca than the fenamates and that it is also a relatively potent blocker of IK, DR and IK, ATP in canine coronary artery smooth muscle cells.

Animals↗
PubMed1994

[Detection of messenger RNA coding for BNP precursor in rat brain by in situ hybridization].

Messenger RNA coding for BNP precursor has been detected and mapped in histological sections of rat brain by in situ hybridization using specific rat BNP DNA probes labelled with 32P. The results showed that areas of highest concentration of BNP gene expression were located in the hypothalamus and in the verge area of the thalamus. Successively decreased concentration could also be found in amydaloid nuclei, olfactory bulb, hippocampus and cerebral cortex. While practically no BNP gene expression could be found in cerebellum and medulla oblongata.

Animals↗
PubMed1994

Neurologic outcome and heart resuscitability with closed-chest cardiopulmonary bypass after prolonged cardiac arrest times in rabbits.

OBJECTIVES: To observe the influence of prolonged cardiac arrest times on neurologic outcome and heart resuscitability, using a resuscitation model with cardiopulmonary bypass in the rabbit, and to determine whether the changes in the plasma concentrations of lactate and lipoperoxide correlate with the severity of global brain ischemia. DESIGN: Randomized, prospective, controlled animal trial. SETTING: University research laboratory. SUBJECTS: Forty-three New Zealand white rabbits. INTERVENTIONS: Rabbits were randomly assigned to one of five groups: control, and four groups with cardiac arrest times of 8, 10, 12, and 15 mins. A bolus of 4 to 6 mL of 0.5-M potassium chloride was injected into the right atrium to induce cardiac arrest within 5 secs. Resuscitation was performed using closed-chest cardiopulmonary bypass, and mechanical ventilation with pure oxygen. When necessary, a DC shock of 10 joules/kg was used to terminate ventricular fibrillation. MEASUREMENTS AND MAIN RESULTS: Hemodynamics, electroencephalogram, electrocardiogram, and return times of various cranial reflexes were observed throughout the experiment. Plasma concentrations of lactate and lipoperoxide were determined before cardiac arrest and 5, 30, 90, and 150 mins after resuscitation. The neurologic outcome, measured by Neurologic Deficit Score, was determined at 150 mins postresuscitation. Values for the Neurologic Deficit Score were: 8 +/- 8 in the control group; 31 +/- 13; 37 +/- 19; 69 +/- 22; and 62 +/- 26 in the cardiac arrest groups of 8, 10, 12, and 15 mins, respectively. No significant differences in cardiac resuscitability were found among the four cardiac arrest groups. The plasma concentrations of lactate and lipoperoxide were significantly higher than the prearrest levels; however, there were no significant differences among the four cardiac arrest groups. CONCLUSIONS: Cardiopulmonary bypass can be used to establish a resuscitation model in rabbits. Neurologic outcome worsens progressively in proportion to the prolonged cardiac times, especially when it exceeds 10 mins. Cardiac resuscitability is still possible, even when arrest time exceeds 15 mins. Changes in plasma concentrations of lactate and lipoperoxide do not correlate with the neurologic outcome and heart resuscitability following cardiac arrest.

Analysis of Variance↗
PubMed1994

[Protective effect of tetramethylpyrazine on ischemic neuronal damage in the gerbil hippocampus].

The effect of tetramethylpyrazine on ischemic neuronal damage was studied in gerbil hippocampus in the terms of histopathological change and cerebral tissue lipid peroxides. Fifteen-five Mongolian gerbils were randomly assigned to one of three groups: sham-operated as control, subjected to 12 min global cerebral ischemia followed by 7 day spontaneous circulatory reperfusion, in which animals were treated with either ip. physiological saline or 60 mg/kg of tetramethylpyrazine 30 min before ischemia and daily thereafter for 7 days. The number of survival pyramidal neurons in the CA1 was counted: 263 +/- 8 (cell/mm) in the sham-operated group, 20 +/- 6 in the ischemia group, and 189 +/- 56 in the group treated with tetramethylpyrazine. Changes in lipid peroxides, expressed as malondialdehyde (MDA), was 134.5 +/- 5.0 nmol/g tissue in the sham-operated group, 193.5 +/- 5.1 in the ischemia group, and 137.6 +/- 10.8 in the group treated with tetramethylpyrazine. These results indicate that tetramethylpyrazine has a protective effect on the ischemic neuronal damage in hippocampus. Free radicals and free calcium may play an important role in pyramidal neuron necrosis in hippocampus following cerebral ischemia.

Animals↗
PubMed1994

Messenger RNA of G-proteins alpha-subunit in rat brown adipose tissue.

The present study was addressed to quantify the steady-state mRNA levels for the alpha subunit of stimulatory (Gs) and inhibitory (Gi-1 and Gi-2) G-proteins in brown (interscapular) male rat adipose tissue (n = 6 rats). The quantification of specific mRNA, estimated using a solution hybridization RNAse protection assay, showed that the amounts of G alpha i-1, G alpha i-2 and G alpha s mRNA were 0.88 +/- 0.28 amol/microgram DNA, 76 +/- 4 amol/micrograms DNA and 460 +/- 16 amol/micrograms DNA, respectively. When the amounts of G alpha i-1 and G alpha i-2 and G alpha s mRNA in brown adipose tissue were compared with those in epididymal white adipose tissue (obtained from the same rats), G alpha i-1 and G alpha i-2 mRNA levels were very similar between brown and white adipose tissue, whereas the level of G alpha s mRNA was significantly higher in brown than in white fat tissue (P < 0.001). In conclusion, the present study shows the steady-state levels of mRNA for the alpha subunit of Gs, Gi-1 and Gi-2 in rat brown fat and suggests that the quantity of G alpha s mRNA is higher in brown than in white adipose tissue. Further studies are needed to explain the possible physiological importance of these findings.

Adipose Tissue↗
PubMed1994

A selective blocker for rested T-type Ca++ channels in guinea pig atrial cells.

The T-type Ca++ channel is widely distributed. Its physiological roles have not been well established because of the lack of a selective T-channel blocker. By using the suction pipette method, the authors describe (7-[[4-[bis(4-fluorophenyl)methyl]-1-piperazinyl]methyl]-2-[(2- hydroxyethyl)amino]4-(1-methylethyl)-2,4,6-cycloheptatrien-1-one) or U-92032, which selectively blocks rested closed T-type Ca++ channels (T channel). After a 3-min exposure to external U-92032 (1 microM), a 50% resting block of the T channel was observed on the first step depolarization from -90 to -40 mV; subsequent stimulations at 0.1 Hz produced little further block. The L-type Ca++ current (L channel) was not affected. At 10 microM, U-92032 produced about 100% resting block of the T and 20% block of the L channels. Subsequent stimulations at 0.1 Hz increased the block of L channel to 56% at the sixth pulse, which indicated strong use dependence at negative potentials and low stimulation rates. Blockade of the T channel did not alter channel steady-state activation and inactivation or current inactivation time courses. By contrast, blockade of the L channel shifted the midpoint of its steady-state inactivation curve from -20.6 mV to -27.8 mV and accelerated its slow inactivation time course, from 171 +/- 16 msec to 79.8 +/- 9.3 msec. Moreover, the 90% recovery time from inactivation was increased from 0.12 to 60 sec. Because U-92032 is ionized at pH 7, its inability to affect the T channel gating property may suggest external drug binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Salicylamide sulfate cell entry in perfused rat liver: a multiple-indicator dilution study.

The hepatocellular entry of salicylamide sulfate conjugate, which binds to both red blood cells and albumin, was examined with the multiple-indicator dilution technique in the perfused rat liver, with medium containing both 20% red cells and 1% albumin (set A), red cells only (set B), albumin only (set C) and neither red cells nor albumin (set D). [14C]Salicylamide sulfate, 51Cr-labeled red cells (a vascular reference), 125I-labeled albumin, [3H]sucrose or [58Co] ethylenediaminetetraacetic acid (EDTA) (high and low molecular weight interstitial references, respectively) and 3H2O or D2O (a cellular reference) were injected as a bolus into the portal vein. Among all sets of outflow data, the earliest immediate vascular recoveries for the [14C] salicylamide sulfate were lower than those for the vascular reference. For sets A and B, the upslopes precessed those for the 58Co-EDTA curve, then crossed over the 58Co-EDTA curves, with lower magnitude peaks occurring at the same time as those for labeled albumin, whereas for sets C and D, in which red cells were absent, the upslopes of [14C]salicylamide sulfate lagged behind those for labeled albumin and [3H]sucrose, reaching lower magnitude peaks coincidental in time with those for labeled sucrose. The precession of the [14C]salicylamide sulfate curve over 58Co-EDTA or [3H]sucrose in the presence (sets A and B) but not in the absence (sets C and D) of red cells and the absence of precession with albumin alone (set C) suggest that a red cell effect on the upslope is more evident than that for albumin. For all experiments, the downslopes of the sulfate curve crossed over those of the labeled red cells, albumin, 58Co-EDTA and sucrose curves and then the water curve at around the peak. The downslopes of the [14C]salicylamide sulfate were similar to those for labeled water, suggesting rapid cellular influx and efflux of salicylamide sulfate. Quantitative evaluation with a barrier-limited space-variable transit-time model for rapidly equilibrating red cell and albumin binding accounted for the upslope effects on [14C]salicylamide sulfate behavior and demonstrated its relatively high liver cell permeability. Values for the unbound permeability surface area product (0.029 to 0.036 ml sec-1.gm-1) were not different, regardless of the presence or absence of red cells and albumin, and slightly exceeded values for hepatic blood flow (0.0186 +/- 0.0016 ml sec-1.gm-1). Comparable influx (0.083 to 0.14 sec-1) and efflux (0.10 to 0.18 sec-1) coefficients were obtained, suggesting rapid cellular entry and efflux of salicylamide sulfate.(ABSTRACT TRUNCATED AT 400 WORDS)

Albumins↗
PubMed1993

An association between air pollution and mortality in six U.S. cities.

BACKGROUND: Recent studies have reported associations between particulate air pollution and daily mortality rates. Population-based, cross-sectional studies of metropolitan areas in the United States have also found associations between particulate air pollution and annual mortality rates, but these studies have been criticized, in part because they did not directly control for cigarette smoking and other health risks. METHODS: In this prospective cohort study, we estimated the effects of air pollution on mortality, while controlling for individual risk factors. Survival analysis, including Cox proportional-hazards regression modeling, was conducted with data from a 14-to-16-year mortality follow-up of 8111 adults in six U.S. cities. RESULTS: Mortality rates were most strongly associated with cigarette smoking. After adjusting for smoking and other risk factors, we observed statistically significant and robust associations between air pollution and mortality. The adjusted mortality-rate ratio for the most polluted of the cities as compared with the least polluted was 1.26 (95 percent confidence interval, 1.08 to 1.47). Air pollution was positively associated with death from lung cancer and cardiopulmonary disease but not with death from other causes considered together. Mortality was most strongly associated with air pollution with fine particulates, including sulfates. CONCLUSIONS: Although the effects of other, unmeasured risk factors cannot be excluded with certainty, these results suggest that fine-particulate air pollution, or a more complex pollution mixture associated with fine particulate matter, contributes to excess mortality in certain U.S. cities.

Adult↗
PubMed1993

Conversion of a magnesium binding site into a zinc binding site by a single amino acid substitution in Escherichia coli alkaline phosphatase.

The replacement of aspartic acid by histidine at position 153 in Escherichia coli alkaline phosphatase results in a mutant enzyme that is remarkably similar to certain mammalian alkaline phosphatases that are activated by magnesium in a time-dependent fashion. These mammalian alkaline phosphatases have histidine at the position corresponding to 153 of the E. coli sequence. Here we report the three-dimensional structure of the mutant E. coli alkaline phosphatase with histidine at position 153. The structure reveals that the octahedral magnesium binding site has been converted to a tetrahedral zinc binding site with an imidazole ring nitrogen of His-153 as one of the ligands to the zinc. The alteration in metal binding caused by the mutation could explain the origin of the magnesium activation observed with the mammalian alkaline phosphatases. The structure also reveals differences in the mode of phosphate binding, explaining the enhanced phosphate affinity and the reduced activity of the mutant enzyme in the presence of zinc.

Alkaline Phosphatase↗
PubMed1993

Binding of magnesium in a mutant Escherichia coli alkaline phosphatase changes the rate-determining step in the reaction mechanism.

To investigate the role of magnesium at the M3 site in Escherichia coli alkaline phosphatase, site-specific mutagenesis was used to substitute Glu-322, a ligand of the Mg2+ with either aspartic acid (E322D) or alanine (E322A). The residual Mg2+ content of the E322D enzyme is about 16-fold lower than that of the wild-type enzyme, and both mutant enzymes exhibit extremely poor catalytic activity compared to the wild-type enzyme. Mg2+ is a strong activator of the E322D enzyme. The hydrolysis activity of the E322D enzyme maximally stimulated by Mg2+ is 60% of that of the wild-type enzyme. Under conditions that measure the sum of hydrolysis and transphosphorylation activities, the kcat of the E322D enzyme in the presence of 500 mM Mg2+ is 2.6-fold higher than the kcat observed for the wild-type enzyme. Zn2+ also activates the E322D enzyme, although it is not as strong an activator as Mg2+. Competition experiments suggest that the activation of the E322D enzyme by Mg2+ and Zn2+ results from binding of either of these metals to the same site on the enzyme. High concentrations of the substrate p-nitrophenyl phosphate inhibit the activity of the E322D enzyme; however, high concentrations of Mg2+ can overcome this inhibition. Stopped-flow experiments indicate that the rate-limiting step of the nonstimulated E322D enzyme at pH 8.0 differs from that of the wild-type enzyme and involves the breaking of the covalent bond between the enzyme and phosphate.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine↗
PubMed1993

Nitric oxide synthase-containing neural processes on large cerebral arteries and cerebral microvessels.

We studied whether neural processes containing nitric oxide synthase (NOS) are associated with large cerebral arteries and/or intraparenchymal microvessels. The presence of NOS-positive nerves on large cerebral arteries was examined in whole-mount preparations processed for NADPH diaphorase histochemistry, a procedure that stains NOS-containing neurons. The association between NOS-containing neural processes and intracerebral microvessels was studied by electron microscopy in ultrathin brain sections reacted with antibodies against NOS. A dense perivascular plexus of NADPH diaphorase positive axons was observed in the anterior portion of the circle of Willis and its branches while in the basilar artery the innervation was less dense. Lesions of the major sources of perivascular innervation of the cerebral arteries indicated that these nerve fibers arise from the sphenopalatine ganglia. Within the brain parenchyma, NOS immunoreactivity was observed in dendrites and axonal terminals closely associated with the basal lamina of arterioles and capillaries. We conclude that NOS-containing nerves of peripheral origin innervate large cerebral arteries while NOS-containing neural processes of central origin, especially dendrites, are closely associated with cerebral arterioles and capillaries. The presence of NOS in perivascular dendrites raises the possibility that these structures are a major source of NO during neural activity. These findings, collectively, provide morphological evidence supporting the hypothesis that NOS neurons participate in the mechanisms that match neural activity to cerebral blood flow.

Amino Acid Oxidoreductases↗
PubMed1993

Magnesium in the active site of Escherichia coli alkaline phosphatase is important for both structural stabilization and catalysis.

Site-specific mutagenesis was used to explore the roles of the side chains of residues Lys-328 and Asp-153 in Escherichia coli alkaline phosphatase. The D153H enzyme exhibits a 3.5-fold decrease in activity at pH 8.0 compared to that of the wild-type enzyme, while a double mutant D153H/K328H exhibits a 16-fold decrease in activity under these conditions. However, the Km values for both enzymes, employing the substrate p-nitrophenyl phosphate, are lower than the value for the wild-type enzyme. The Ki for phosphate, which is pH- and Mg(2+)-dependent, is decreased for the D153H enzyme and increased for the D153H/K328H enzyme. Relative to the wild-type enzyme, both mutant enzymes bind Mg2+ more weakly and undergo a time-dependent activation induced by Mg2+. The half-time of the activation process is independent of the Mg2+ concentration, indicating that the activation most probably involves a conformational change. The pH versus activity profiles of both enzymes are altered relative to that of the wild-type enzyme and exhibit greatly enhanced activity, relative to that of the wild-type enzyme, at high pH values. The pre-steady-state kinetics for the D153H and D153H/K328H enzymes exhibit a transient burst of product formation at pH 8.0, under conditions at which the wild-type enzyme exhibits no transient burst, indicating that at pH 8.0 the hydrolysis of the covalent enzyme-phosphate complex is rate-determining and not the release of phosphate from the noncovalent enzyme-phosphate complex as is observed for the wild-type enzyme. Therefore, these mutations are directly influencing catalysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1993

Localization of NADPH diaphorase in neurons of the rostral ventral medulla: possible role of nitric oxide in central autonomic regulation and oxygen chemoreception.

We studied whether neurons containing nitric oxide synthase (NOS) are localized to the rostral ventrolateral medulla (RVM) and, if so, whether they are distinct from the adrenergic neurons of the C1 group. NOS-containing neurons and/or C1 neurons were visualized using NADPH diaphorase histochemistry and phenylethanolamine N-methyltransferase (PNMT) immunohistochemistry, respectively. A column of NADPH diaphorase-positive neurons, extending 2 mm in the rostrocaudal plane, was observed lateral to the inferior olive and medial to the C1 neurons. Double labelling studies showed that NADPH diaphorase-positive neurons were not immunoreactive for PNMT, indicating that the two enzymes were localized in the different cells. Furthermore, only a small fraction of NADPH diaphorase neurons were retrogradely labelled after injections of fluorogold into the thoracic cord. We conclude that the RVM contains a well-defined group of neurons endowed with NOS that are distinct from the adrenergic neurons of the C1 group and have only limited monosynaptic projections to the spinal cord. Since the RVM is involved in the control of arterial pressure and in oxygen-conserving reflexes, the findings raise the possibility that nitric oxide participates in central autonomic regulation and oxygen chemoreception.

Animals↗
PubMed1993

DNA sequencing of the seven remaining structural genes of the gene cluster encoding the energy-transducing NADH-quinone oxidoreductase of Paracoccus denitrificans.

In our previous papers, seven structural genes (NQO1-7) of the energy-transducing NADH-quinone (Q) oxidoreductase of Paracoccus denitrificans were characterized [Xu, X., Matsuno-Yagi, A., & Yagi, T. (1991a) Biochemistry 30, 8678-8684; (1991b) Biochemistry 30, 6422-6428; (1992a) Biochemistry 31, 6925-6932; (1992b) Arch. Biochem. Biophys. 296, 40-48]. This paper reports the identification, cloning, and sequencing of seven additional structural genes in the same gene cluster (P. denitrificans enzyme complex). These seven genes, designated NQO8-14, are composed of 1038, 492, 603, 306, 2112, 1542, and 1500 base pairs, respectively. The polypeptides encoded by the NQO8-14 genes are homologous, respectively, to the ND1 product, the 23-kDa polypeptide, and the ND6, ND4L, ND5, ND4, and ND2 products of the bovine NADH-Q oxidoreductase. The order of the 14 structural genes of the Paracoccus energy-transducing NADH-Q oxidoreductase in the gene cluster is NQ07, NQO6, NQO5, NQO2, NQO1, NQO3, NQO8, NQO9, NQO10, NQO11, NQO12, NQO13, and NQO14. Downstream from the NQO14 gene an open reading frame (designated URF240) was detected which encodes a predicted polypeptide homologous to the biotin [acetyl-CoA-carboxylase] ligase of Escherichia coli. In addition, a putative terminal sequence motif was observed downstream of the NQO14 gene, suggesting that the structural gene NQO14 is the 3'-terminal gene of the Paracoccus NADH-Q oxidoreductase gene cluster. Nucleotide sequencing of the entire gene cluster revealed the presence of three unidentified reading frames: one between the NQO3 and NQO8 genes and other two between the NQO9 and NQO10 genes. These are designated URF4, URF5, and URF6 and are composed of 768, 393, and 405 base pairs, respectively. The possible functions of the putative proteins encoded by URF5 and URF6 are discussed.

Amino Acid Sequence↗