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ABSTRACT: Transcription initiation by eukaryotic RNA polymerase (Pol) III relies on the TFIIE-related subcomplex C82/34/31. Here we combine cross-linking and hydroxyl radical probing to position the C82/34/31 subcomplex around the Pol III active center cleft. The extended winged helix (WH) domains 1 and 4 of C82 localize to the polymerase domains clamp head and clamp core, respectively, and the two WH domains of C34 span the polymerase cleft from the coiled-coil region of the clamp to the protrusion. The WH domains of C82 and C34 apparently cooperate with other mobile regions flanking the cleft during promoter DNA binding, opening, and loading. Together with published data, our results complete the subunit architecture of Pol III and indicate that all TFIIE-related components of eukaryotic and archaeal transcription systems adopt an evolutionarily conserved location in the upper part of the cleft that supports their functions in open promoter complex formation and stabilization.
Proceedings of the National Academy of Sciences 11/2012; · 9.68 Impact Factor
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ABSTRACT: Eukaryotic RNA polymerase III (Pol III) relies on a transcription factor TFIIF-like Rpc37/53 subcomplex for promoter opening, elongation, termination, and reinitiation. By incorporating the photoreactive amino acid p-benzoyl-L-phenylalanine (BPA) into Rpc37, Rpc53, and the Rpc2 subunit of Pol III, we mapped protein-protein interactions, revealing the position of Rpc37/53 within the Pol III preinitiation complex (PIC). BPA photo-cross-linking was combined with site-directed hydroxyl radical probing to localize the Rpc37/53 dimerization module on the lobe/external 2 domains of Rpc2, in similarity to the binding of TFIIF on Pol II. N terminal to the dimerization domain, Rpc53 binds the Pol III-specific subunits Rpc82 and Rpc34, the Pol III stalk, and the assembly factor TFIIIC, essential for PIC formation. The C-terminal domain of Rpc37 interacts extensively with Rpc2 and Rpc34 and contains binding sites for initiation factor Bdp1. We also located the C-terminal domain of Rpc37 within the Pol III active center in the ternary elongation complex, where it likely functions in accurate termination. Our work explains how the Rpc37/53 dimer is anchored on the Pol III core and acts as a hub to integrate a protein network for initiation and termination.
Molecular and cellular biology 07/2011; 31(13):2715-28. · 6.06 Impact Factor
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ABSTRACT: Sumoylation regulates a wide range of cellular processes. However, little is known about the regulation of the SUMO machinery. In this study, we demonstrate that two lysine residues (Lys-153 and Lys-157) in the C-terminal region of the yeast E2-conjugating enzyme Ubc9 are the major and minor autosumoylation sites, respectively. Surprisingly, mutation of Lys-157 (ubc9(K157R)) significantly stimulates the level of Ubc9 autosumoylation at Lys-153. The functional role of Ubc9 autosumoylation is exemplified in our findings that cell cycle-dependent sumoylation of cytoskeletal septin proteins is inversely correlated with the Ubc9 autosumoylation level and that mutation of the Ubc9 autosumoylation sites results in aberrant cell morphology. Our study elucidates a regulatory mechanism that utilizes automodification of the E2 enzyme of the sumoylation machinery to control substrate sumoylation.
Journal of Biological Chemistry 06/2011; 286(24):21826-34. · 4.77 Impact Factor
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ABSTRACT: Hyperbilirubinemia is one of the most common causes for hospital admission in neonatal infants. Previous studies have found that jaundice may be one of the initial symptoms related to urinary tract infection (UTI) in infants. This study is to evaluate the incidence and related factors of neonatal infants with the initial presentation of hyperbilirubinemia and final diagnosis of UTI in a tertiary teaching hospital.
We retrospectively investigated the medical records of admitted infants younger than 8 weeks old with hyperbilirubinemia between January and December 2008. The jaundiced infants having tests of urinalysis were enrolled into our study and grouped into UTI or no UTI group according to the findings of urinary culture.
A total of 217 neonatal jaundiced infants were enrolled. Among them, 12 cases (5.5%) were grouped into the UTI group, and the most common cultured bacterium from their urine was Escherichia coli. There was no significant difference in the babies' birth weight, maternal conditions, or total bilirubin levels between the two groups. There was also no significant difference between the two groups in their admission age (9.7 ± 13.5 days vs. 6.1 ± 6.7 days in UTI and no UTI groups, respectively) or the ratio of outpatients (50% vs. 25% in UTI and no UTI groups, respectively) (p > 0.05). The cases of UTI group had significantly lower hemoglobin (15.2 ± 2.7 g/dL vs. 17.2 ± 2.3 g/dL, respectively) and higher formula feeding rate (8.3% vs. 2.9%, respectively) than the no UTI group (p < 0.05).
The incidence of UTI in the admitted infants with hyperbilirubinemia was as high as approximately 5.5%. The most common cultured bacterium in urine was E coli. Therefore, performing urinary tests to exclude the possibility of coincidental UTI may be necessary for admitted jaundiced infants younger than 8 weeks old.
Journal of the Chinese Medical Association 04/2011; 74(4):159-63. · 0.79 Impact Factor
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ABSTRACT: Inter- and intragenic noncoding transcription is widespread in eukaryotic genomes; however, the purpose of these types of transcription is still poorly understood. Here, we show that intragenic sense-oriented transcription within the budding yeast ASP3 coding region regulates a constitutively and immediately accessible promoter for the transcription of full-length ASP3. Expression of this short intragenic transcript is independent of GATA transcription factors, which are essential for the activation of full-length ASP3, and independent of RNA polymerase II (RNAPII). Furthermore, we found that an intragenic control element is required for the expression of this noncoding RNA (ncRNA). Continuous expression of the short ncRNA maintains a high level of trimethylation of histone H3 at lysine 4 (H3K4me3) at the ASP3 promoter and makes this region more accessible for RNAPII to transcribe the full-length ASP3. Our results show for the first time that intragenic noncoding transcription promotes gene expression.
RNA 11/2010; 16(11):2085-93. · 5.09 Impact Factor
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ABSTRACT: Background: To delineate the association between corneal arcus and potential cardiovascular risk factors in middle-aged population.
Methods: This cross-sectional study randomly enrolled 119 subjects with corneal arcus and 119 subjects without arcus, aged between 30 and 60 years, from community-based East Asian population. Corneal arcus identification was completed by a single ophthalmologist using slit-lamp biomicroscopy examination. Cardiovascular risk factor parameters were measured by standardized techniques.
Results: Subjects with higher levels of total-cholesterol, low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), and total/HDL cholesterol ratio had increased risk of having corneal arcus, whereas subjects with higher systolic blood pressure (SBP) and diastolic blood pressure had decreased risk. Using stepwise logistic regression analysis, we found that male gender was a strong independent risk factor for arcus formation [odds ratio (OR): 2.87; 95% confidence interval (CI): 1.59-5.17; P < 0.001]. Higher non-HDL-C level also had significant but mildly increased risk (OR: 1.02; 95% CI: 1.01-1.02; P 0.008) of having arcus, whereas higher SBP had significant but mildly decreased risk (OR: 0.98; 95% CI: 0.96-0.99; P < 0.001). Besides, subjects who had circumferential arcus had significantly higher risk of having LDL-C ≧160 mg/dL than those who had only partial arcus (OR: 5.79 versus OR: 4.60; P < 0.001).
Conclusions: In addition to serum LDL-C, male gender and serum non-HDL-C level are significantly correlated to corneal arcus. Conversely, SBP is negatively correlated to corneal arcus. Presence of corneal arcus in middle-aged men may be an indicator for dyslipidemia, and we speculate that the relationship between arcus and coronary heart disease may be dependent of dyslipidemia.
The American Journal of the Medical Sciences 09/2009; 338(4):268-272. · 1.39 Impact Factor
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ABSTRACT: Vitrification is widely applied to transform hazardous materials into inert slags. Raising the value of the recycled slag is an important issue from an economic point of view. In this study, an alternative approach for mixing a plasma slag with unsaturated polyester resin for making the dough-like molding composites is proposed. Physical properties, including ultimate tensile strength, Rockwell hardness, and the elongation at break, were measured to evaluate the characteristics of the composites. A scanning electron microscope and an X-ray diffractometer were used to examine the micro characteristics of the specimens. The chemical stability of the composites was estimated using the toxicity characteristic leaching procedure and a hot water bathing process. In an optimal slag loading (mass ratio of slag to unsaturated polyester resin) ranged from 0.1 to 0.2, the slag powder improved the physical properties of the composites. With an increased slag loading, excess slag powder weakened the structure of the resin, reducing the ultimate tensile strength and Rockwell hardness. The acid and water bathing tests indicated that the resin is decomposed in a hot environment. However, the slag was not destructed nor were the hazardous metals leached out. The results show that the molding method is an effective technology to recycle the slag.
Journal of Hazardous Materials 09/2008; 156(1-3):442-7. · 4.17 Impact Factor
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ABSTRACT: The metal-ferrite (chromium-ferrite and zinc-ferrite) sorbents made from the heavy metal wastewater sludge have been developed for the hydrogen sulfide removal from coal gas. The high temperature absorption of hydrogen sulfide from coal gas with the metal-ferrite sorbent in a fixed bed reactor was conducted in this study. The metal-ferrite powders were the products of the ferrite process for the heavy metal wastewater treatment. The porosity analysis results show that the number of micropores of the sorbents after sulfidation and regeneration process decreases and the average pore size increases due to the acute endothermic and exothermic reactions during the sulfidation-regeneration process. The FeS, ZnS, and MnS peaks are observed on the sulfided sorbents, and the chromium extraction of the CFR6 can fulfill the emission standard of Taiwan EPA. The suitable sulfidation temperature range for chromium-ferrite sorbent is at 500-600 degrees C. In addition, effects of various concentrations of H2 and CO were also conducted in the present work at different temperatures. By increasing the H2 concentration, the sulfur sorption capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction.
Journal of Hazardous Materials 04/2008; 160(2-3):482-8. · 4.17 Impact Factor
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ABSTRACT: On account of the infectious properties of medical wastes, most are treated carefully by incineration to ensure proper destruction of pathogens. However, the behaviors of medical wastes are not well understood during the process of incineration. Thus, the aim of this work is to investigate pyrolysis and oxidation kinetics of the medical wastes, including cottons, gauzes, saline bottles, stomach medicines with the thermal gravimetric analysis (TGA) method. Experimentally, the degradation of cottons and saline bottles in pyrolysis and oxidation occurred at about 530 K and 510 K as well as 630 K and 530 K, respectively. Oxygen affects the degradation reaction of cottons and saline bottles at lower temperatures. The rate equations of the first stage of thermal treatment in different oxygen contents also showed that oxygen would decrease the activation energies of decomposition of cottons, gauzes and saline bottles. But the presence of oxygen did not influence the decomposition of stomach medicines at temperatures below 550 K, while only pyrolysis took place.
Environmental Technology 03/2006; 27(2):153-8. · 1.41 Impact Factor
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ABSTRACT: In this study, the X-ray absorption near-edge structure shows that poisonous Cr 6+ in the laboratory wasteliquid were reduced to Cr 3+ by adding Fe 2+ at [Fe 2+ /total metal, mole ratio higher than 4:1. The X-ray diffraction analysis shows that greater the [Fe 2+ /total metal] mole ratios used (such as 6:1, 10:1, 20:1 and 30:1), the more spinel-structured ferrites were formed (0.26, 0.30, 0.48 and 0.59). When [Fe 2+ /total metal] mole ratio was larger than 20:1, the saturation magnetization and coercive field were about 5.21 emu/g and 6.2 kOe, respectively. The ferrite precipitates could be recovered as magnitude materials. However, the TCLP test result was beyond the standard of EPA when the [Fe 2+ / total metal] mole ratio was 30:1. The optimum operation for the laboratory wasteliquid by ferrite process in the [Fe 2+ / total metal] mole ratio was 20:1.
Radiation Physics and Chemistry. 01/2006; 75:1884-1887.
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ABSTRACT: This investigation attempts to understand the critical soluble salts in natural mudstone and the leaching, microstructural, and microchemical characteristics in soaked mudstone using scanning electron microscopy (SEM)/energy-dispersive X-ray analysis (EDAX), X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), conductivity measurement, ion chromatography (IC), and environmental scanning electron microscopy (ESEM)/EDAX techniques. Natural mudstone probably includes soluble salts such as Na2SO4, NaCl, NaCO3, and CaCO3. The dissolution of Na2SO4 controls water-sensitive mudstone very susceptible to slaking and dispersion. ESEM micrographs clearly show evidence of mudstone-slaking during soaking since the visible pores are filled with small aggregative masses. A calcium-bearing precipitate from the soaked mudstone is speculated to be attributable to the decomposition of the hydrated product of the fresh mudstone.
Journal of Environmental Science and Health Part A 06/2003; 38(5):909-22. · 1.19 Impact Factor
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ABSTRACT: This study attempt to determine the swelling deformation of compacted mudstone using the free swell test, and the leaching parameters using a pH meter, a conductivity meter, and ion chromatography (IC) techniques. Closely examining chemical characteristics indicated that natural mudstone is saline-alkali soil. The maximum swelling deformation obtained from the free swell test is about 15.7%. The swelling developed relatively rapidly after the start of soaking, stopping after 7 days. The leaching characteristics in compacted mudstone involve the hydrolysis of Na+ ions, the precipitation of CaCO3 and slightly dissolution of Mg2+ ion. The relationship of swelling deformation to sodium adsorption ratio (SAR) value indicated that the SAR value in soaking suspension significantly affects the amount of swelling. Additionally, the pH of the soaking suspension importantly affects swelling behavior. Overall, the early swelling behaviors of compacted mudstone are posited to involve directly the concentration of Na+ ions in the soaking suspension and the precipitation of CaCO3 in compacted mudstone. Furthermore, the very slight swelling after the 3-day soaking is related to the dissolution of Mg2+ ions in compacted mudstone.
Journal of Environmental Science and Health Part A 04/2003; 38(3):563-76. · 1.19 Impact Factor
