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Liu B, Zeng L, Mao J, Ren Q. Simulation of Levulinic Acid Adsorption in Packed Beds using Parallel Pore/Surface Diffusion Model. Chem Eng Technol 2010. [DOI: 10.1002/ceat.201000147] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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77
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Xiong H, Lin H, Xvi H, Shi C, Xie H, Ren X, Huang G, Wang A, Cui Z, Cheng J, Yi L, Wu Y, Zhao Y, Xu B, Zu C, Zhang Y, Xu R, Bian Y, Ma X, Zhang L, Ren Q, Cheng L. Post-earthquake outbreak of insecticide-associated conjunctivitis in a primary school of Lixian district, China: An epidemiological investigation. Public Health 2010; 124:332-8. [DOI: 10.1016/j.puhe.2010.02.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 01/28/2010] [Accepted: 02/22/2010] [Indexed: 10/19/2022]
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78
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Kondkar AA, Bray MS, Leal SM, Nagalla S, Liu DJ, Jin Y, Dong JF, Ren Q, Whiteheart SW, Shaw C, Bray PF. VAMP8/endobrevin is overexpressed in hyperreactive human platelets: suggested role for platelet microRNA. J Thromb Haemost 2010; 8:369-78. [PMID: 19943878 PMCID: PMC3312605 DOI: 10.1111/j.1538-7836.2009.03700.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Variation in platelet reactivity contributes to disorders of hemostasis and thrombosis, but the molecular mechanisms are not well understood. OBJECTIVES To discover associations between interindividual platelet variability and the responsible platelet genes, and to begin to define the molecular mechanisms altering platelet gene expression. SUBJECTS/METHODS Two hundred and eighty-eight healthy subjects were phenotyped for platelet responsiveness. Platelet RNA from subjects demonstrating hyperreactivity (n=18) and hyporeactivity (n=11) was used to screen the human transcriptome. RESULTS Distinctly different mRNA profiles were observed between subjects with differing platelet reactivity. Increased levels of mRNA for VAMP8/endobrevin, a critical v-SNARE involved in platelet granule secretion, were associated with platelet hyperreactivity (Q=0.0275). Validation studies of microarray results showed 4.8-fold higher mean VAMP8 mRNA levels in hyperreactive than hyporeactive platelets (P=0.0023). VAMP8 protein levels varied 13-fold among platelets from these normal subjects, and were 2.5-fold higher in hyperreactive platelets (P=0.05). Among our cohort of 288 subjects, a VAMP8 single-nucleotide polymorphism (rs1010) was associated with platelet reactivity in an age-dependent manner (P<0.003). MicroRNA-96 was predicted to bind to the 3'-untranslated regionof VAMP8 mRNA and was detected in platelets. Overexpression of microRNA-96 in VAMP8-expressing cell lines caused a dose-dependent decrease in VAMP8 protein and mRNA, suggesting a role in VAMP8 mRNA degradation. CONCLUSIONS These findings support a role for VAMP8/endobrevin in the heterogeneity of platelet reactivity, and suggest a role for microRNA-96 in the regulation of VAMP8 expression.
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Wang XQ, Ren Q, Sun J, Yang HL, Li TB, Fan HL, Zhang GH, Xu D, Zhao JH. Preparation, physicochemical and third order nonlinear optical properties of bis(tetrabutylammonium)bis(2-thioxo-1,3-dithiole-4,5-dithiolato)mercurate(II). CRYSTAL RESEARCH AND TECHNOLOGY 2009. [DOI: 10.1002/crat.200900082] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Palenik B, Ren Q, Tai V, Paulsen IT. Coastal Synechococcus metagenome reveals major roles for horizontal gene transfer and plasmids in population diversity. Environ Microbiol 2009; 11:349-59. [PMID: 19196269 DOI: 10.1111/j.1462-2920.2008.01772.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The extent to which cultured strains represent the genetic diversity of a population of microorganisms is poorly understood. Because they do not require culturing, metagenomic approaches have the potential to reveal the genetic diversity of the microbes actually present in an environment. From coastal California seawater, a complex and diverse environment, the marine cyanobacteria of the genus Synechococcus were enriched by flow cytometry-based sorting and the population metagenome was analysed with 454 sequencing technology. The sequence data were compared with model Synechococcus genomes, including those of two coastal strains, one isolated from the same and one from a very similar environment. The natural population metagenome had high sequence identity to most genes from the coastal model strains but diverged greatly from these genomes in multiple regions of atypical trinucleotide content that encoded diverse functions. These results can be explained by extensive horizontal gene transfer presumably with large differences in horizontally transferred genetic material between different strains. Some assembled contigs showed the presence of novel open reading frames not found in the model genomes, but these could not yet be unambiguously assigned to a Synechococcus clade. At least three distinct mobile DNA elements (plasmids) not found in model strain genomes were detected in the assembled contigs, suggesting for the first time their likely importance in marine cyanobacterial populations and possible role in horizontal gene transfer.
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Yin H, Liu Z, Guan G, Liu A, Ma M, Ren Q, Luo J. Detection and differentiation of Theileria luwenshuni and T. uilenbergi infection in small ruminants by PCR. Transbound Emerg Dis 2008; 55:233-7. [PMID: 18666967 DOI: 10.1111/j.1865-1682.2008.01031.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Theileria luwenshuni and T. uilenbergi are newly identified Theileria species highly pathogenic for sheep and goats in China. As they are morphologically indistinguishable and poorly characterized, there is no easily applicable method available to differentiate between these species. In the present study, PCR assays are described for the differentiation and detection of T. luwenshuni and T. uilenbergi using species-specific primers, which were designed based on the hypervariable region of the small subunit ribosomal RNA gene sequences. By testing 100 field blood samples of sheep collected from five geographically different regions where the Theileria species were described to be prevalent, the PCR assays not only detected infected samples but also identified mixed infection. This suggests that these PCR assays are useful tools for the detection of and differentiation between T. luwenshuni and T. uilenbergi.
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Ren Q, Han XY, Wang F, Zhang XY, Han LC, Luo YY, Zhou XH, Ji LN. Exon sequencing and association analysis of polymorphisms in TCF7L2 with type 2 diabetes in a Chinese population. Diabetologia 2008; 51:1146-52. [PMID: 18493736 DOI: 10.1007/s00125-008-1039-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 04/08/2008] [Indexed: 01/18/2023]
Abstract
AIMS/HYPOTHESIS Recently, variants in the transcription factor 7-like 2 (TCF7L2) gene have been found to be consistently associated with type 2 diabetes in different populations. In this study, we hypothesized that TCF7L2 also contributed to genetic susceptibility for type 2 diabetes in a Chinese population. METHODS We looked for new variants by direct sequencing of all exons and intron-exon junctions of TCF7L2 in 100 Chinese type 2 diabetic patients, and then we genotyped five single nucleotide polymorphisms (SNPs) by Snapshot technology in 1,000 Chinese individuals. RESULTS By sequencing, we identified six SNPs (c.1,637C>A; c.1,674C>G; c.1,709G>A; c.1,846C>G; c.1,888C>T; and c.1,876T>G), and three of them led to non-synonymous polymorphisms (c.1,637C>A, His-->Gln or Pro-->Thr; c.1,674C>G, Pro-->Arg; and c.1,709G>A, Ala-->Thr). All of them are rare except c.1,637C>A, which had a frequency of 0.23 for the minor A allele in 98 sequenced individuals. In a case-control study, one of the newly discovered SNPs (c.1,637C>A), together with four reported ones (rs7903146, rs12255372, rs290487 and rs3814573) were genotyped. Comparison between allele and genotype frequencies of these SNPs in patients and controls showed marginal association for rs7903146 and rs290487 with type 2 diabetes (p = 0.063, OR 1.982, 95% CI 1.128-3.485; p = 0.071, OR 1.237, 95% CI 0.983-1.557, respectively). No association was found for rs12255372, rs3814573, c.1,637C>A and type 2 diabetes (p = 0.278-1.000). CONCLUSIONS/INTERPRETATION With the current sample size, we did not find any mutation in the coding sequence of TCF7L2 that confers a genetic risk for type 2 diabetes in a Chinese population, and did not replicate some of the major positive results obtained in other populations.
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Liu H, Dang Y, Chai X, Wang Z, Ma L, Ren Q. Treatment of port-wine stains with the 595-nm pulsed dye laser: a pilot study in Chinese patients. Clin Exp Dermatol 2007; 32:646-9. [DOI: 10.1111/j.1365-2230.2007.02517.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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84
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Krieg RC, Herr A, Raupach K, Ren Q, Schwamborn K, Knuechel R. Analyzing effects of photodynamic therapy with 5-aminolevulinic acid (ALA) induced protoporphyrin IX (PPIX) in urothelial cells using reverse phase protein arrays. Photochem Photobiol Sci 2007; 6:1296-305. [PMID: 18046485 DOI: 10.1039/b704464j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PPIX) is clinically established approach for a number of defined applications. However, in order to optimize the therapeutic benefits of PDT, the specific mode of cell destruction should be better defined. Apoptosis is favored over necrosis for clinical practice as the latter causes more side-effects. In the present study, we analyse PDT-induced cell death and its correlation to various PDT parameters (different doses applied, time after PDT treatment) in vitro using reverse phase protein arrays. Human urothelial cell lines with varying degrees of differentiation (UROtsa, RT4, RT112, J82) were subjected to in vitro-PDT using increasing doses of irradiation. In addition, positive controls for apoptosis, necrosis and un-/specific cellular damage were included. Cells were harvested over a specified time course, lysed and arrayed onto nitrocellulose-covered glass slides. The arrays were analyzed for expression of apoptosis-related proteins by immunohistochemistry. Analysis of caspase-3 and -9 expression, the activation of HIF-1alpha, Bcl2, Cox2 and the phosphorylation of AKT reveals signal activation due to a PDT-stimulus in correlation with the positive controls. Data were analyzed by unsupervised hierarchical clustering and depicted as a heat map revealing cell-specific patterns of pathway stimulation. Higher differentiated phenotypes showed a more distinct signal response in general and a higher apoptotic response in detail. Lower differentiated cell lines lost pathway regulation capabilities according to their state of dedifferentiation. Reverse phase protein arrays are a promising technique for signal pathway profiling: they exceed the range of traditional western blots by sensitivity, high-throughput capability, minimal sample consumption and easy quantification of results obtained.
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Moran MA, Belas R, Schell MA, González JM, Sun F, Sun S, Binder BJ, Edmonds J, Ye W, Orcutt B, Howard EC, Meile C, Palefsky W, Goesmann A, Ren Q, Paulsen I, Ulrich LE, Thompson LS, Saunders E, Buchan A. Ecological genomics of marine Roseobacters. Appl Environ Microbiol 2007; 73:4559-69. [PMID: 17526795 PMCID: PMC1932822 DOI: 10.1128/aem.02580-06] [Citation(s) in RCA: 246] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterioplankton of the marine Roseobacter clade have genomes that reflect a dynamic environment and diverse interactions with marine plankton. Comparative genome sequence analysis of three cultured representatives suggests that cellular requirements for nitrogen are largely provided by regenerated ammonium and organic compounds (polyamines, allophanate, and urea), while typical sources of carbon include amino acids, glyoxylate, and aromatic metabolites. An unexpectedly large number of genes are predicted to encode proteins involved in the production, degradation, and efflux of toxins and metabolites. A mechanism likely involved in cell-to-cell DNA or protein transfer was also discovered: vir-related genes encoding a type IV secretion system typical of bacterial pathogens. These suggest a potential for interacting with neighboring cells and impacting the routing of organic matter into the microbial loop. Genes shared among the three roseobacters and also common in nine draft Roseobacter genomes include those for carbon monoxide oxidation, dimethylsulfoniopropionate demethylation, and aromatic compound degradation. Genes shared with other cultured marine bacteria include those for utilizing sodium gradients, transport and metabolism of sulfate, and osmoregulation.
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Wang XQ, Xu D, Ren Q, Zhang GH, Sun XB, Hou XQ, Guo WF, Lü H. Preparation, single crystal growth and characterization of bis(tetrabutylammonium)bis(4,5-dithiolato-1,3-dithiole-2-thione)copper. CRYSTAL RESEARCH AND TECHNOLOGY 2007. [DOI: 10.1002/crat.200610827] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wang JX, Zhao XF, Liang YL, Li L, Zhang W, Ren Q, Wang LC, Wang LY. Molecular characterization and expression of the antimicrobial peptide defensin from the housefly (Musca domestica). Cell Mol Life Sci 2006; 63:3072-82. [PMID: 17131057 PMCID: PMC11136183 DOI: 10.1007/s00018-006-6284-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A 430-bp cDNA encoding the insect antimicrobial peptide defensin was cloned from the housefly, and designated Musca domestica defensin (Mdde). The open reading frame of the cDNA encoded a 92-amino acid peptide with an N-terminal signal sequence followed by a propeptide that is processed by cleavage to a 40-amino acid mature peptide. Northern analysis and in situ hybridization identified the corresponding mRNA in the fat body of bacterially challenged houseflies and in the epidermis of the body wall of naive and challenged houseflies. The Gram-negative bacterium (Escherichia coli) is a strong inducer of the gene. By RT-PCR, Mdde mRNA was also detected in naive and challenged insects. These findings suggest that the defensin gene is constitutively expressed in the epidermis of the housefly body wall. The predicted mature form of Mdde was expressed as a recombinant peptide in E. coli and Pichia pastoris. The recombinant Mdde expressed in Pichia was active against Gram-positive and some Gram-negative bacteria.
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Ren Q, Kari C, Quadros M, Sui Y, Kamer S, Dicker A, Rodeck U. 2648. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.1063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kamer S, Ren Q, Sui Y, Kari C, Rodeck U, Dicker A. 2334. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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90
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Yi G, Coleman S, Ren Q. CUSUM method in predicting regime shifts and its performance in different stock markets allowing for transaction fees. J Appl Stat 2006. [DOI: 10.1080/02664760600708590] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ferreira MEDS, Colombo AL, Paulsen I, Ren Q, Wortman J, Huang J, Goldman MHS, Goldman GH. The ergosterol biosynthesis pathway, transporter genes, and azole resistance in Aspergillus fumigatus. Med Mycol 2005; 43 Suppl 1:S313-9. [PMID: 16110826 DOI: 10.1080/13693780400029114] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The continuous use of triazoles can result in the development of drug resistance. Azole-resistant clinical isolates, spontaneous and induced mutants of Aspergillus fumigatus have been documented. The azoles block the ergosterol biosynthesis pathway by inhibiting the enzyme 14-alpha-demethylase, product of the CYP51. Fungal azole resistance involves both amino acid changes in the target site that alter drug-target interactions and those that decrease net azole accumulation. The reduced intracellular accumulation has also been correlated with overexpression of multidrug resistance (MDR) efflux transporter genes of the ATP-binding cassette (ABC) and the major facilitator superfamily (MFS) classes. About 20 genes are involved in the A. fumigatus ergosterol biosynthesis pathway. There are several duplicated genes in this pathway. Interestingly, erg3 and erg11 showed two copies in A. fumigatus. In general, Aspergillus spp. have proportionally more MFS transporter encoding genes than Saccharomyces cerevisiae, S. pombe, and Neurospora crassa. The drug H+ (12 and 14 spanners) sub-families are also proportionally greater than in the other species. Although the numbers of ABC transporter encoding genes are comparable, again the Aspergillus spp. have more ABC transporters related to multidrug permease than the other fungal species.
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Wang XQ, Xu D, Chow YT, Cheng XF, Liu WL, Yu WT, Zhang GH, Ren Q, Lü MK, Yuan DR, Zhao SR. Physicochemical properties of the organometallic nonlinear optical crystal: MnHg(SCN)4(C3H8O2). CRYSTAL RESEARCH AND TECHNOLOGY 2004. [DOI: 10.1002/crat.200310246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wang X, Xu D, Lu M, Yuan D, Cheng X, Huang J, Wang S, Yu W, Sun H, Duan X, Ren Q, Yang H. Growth morphology and thermal properties of the organometallic nonlinear optical crystal: MnHg(SCN)4(C2H6OS)2. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(02)01706-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jiang P, Fu S, Cang H, Wang X, Ren Q, Yuan Y, Meng T, Kang H, Hu J, Chen C, Yang Z, Bi R. A Controllable and Observable Protein Cystallization Facility. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 2003; 32:243-249. [PMID: 14696591 DOI: 10.1016/s0273-1177(03)90258-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A Controllable and Observable Protein Crystallization Facility (ACOP) was developed in 1999 for space experiment in the Get Away Special canister of Space Shuttle. To regulate the vapor diffusion rate, in a crystallization chamber, five cells each containing precipitant solution of different concentrations, exposed to one protein cell in turn. Five layers of chambers were overlapped coaxially. The crystallization process was observed and recorded by digital cameras. Structure of facility and result of image sequence were given.
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Elbein SC, Chu W, Ren Q, Wang H, Hemphill C, Hasstedt SJ. Evaluation of apolipoprotein A-II as a positional candidate gene for familial Type II diabetes, altered lipid concentrations, and insulin resistance. Diabetologia 2002; 45:1026-33. [PMID: 12136402 DOI: 10.1007/s00125-002-0850-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2001] [Revised: 03/06/2002] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS We hypothesized that apolipoprotein A-II sequence variation was responsible for the observed linkage of Type II (non-insulin-dependent) diabetes mellitus to the apolipoprotein A-II region in Northern European families ascertained for multiple diabetic siblings, and might also influence insulin sensitivity and secretion, non-esterified fatty acids, and lipids. METHODS We recruited 698 members of 63 families for pedigree studies and additional unrelated people providing 117 diabetic and 130 control subjects. We screened the apolipoprotein A-II gene by single strand conformation polymorphism analysis and fluorescent sequence analysis. Variants were typed by oligonucleotide ligation assay, restriction digest of amplification products, or radioactive fragment analysis for the microsatellite polymorphism. Association of each variant with Type II diabetes was tested in the case-control population by chi-square analysis, or using transmission disequilibrium test in families. Haplotypes were established in families using SIMWALK and tested for association with diabetes and quantitative traits. RESULTS No detected variant altered the coding sequence of the gene. Three single nucleotide polymorphisms showed modest evidence for an association, but no variant or haplotype was associated with diabetes in families. Similarly, we found no association with non-esterified fatty acid concentrations, HDL concentrations, or fasting insulin. In contrast, we found evidence for an association of some haplotypes and individual variants with 2-h post-challenge glucose and measures of insulin secretion. CONCLUSION/INTERPRETATION Apolipoprotein A-II is not likely to explain the observed linkage of Type II diabetes, but variation in this gene could alter insulin secretion and post-challenge glucose.
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Ren Q, Thony-Meyer L. Physical interaction of CcmC with heme and the heme chaperone CcmE during cytochrome c maturation. J Biol Chem 2001; 276:32591-6. [PMID: 11384983 DOI: 10.1074/jbc.m103058200] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biogenesis of c-type cytochromes requires the covalent attachment of heme to the apoprotein. In Escherichia coli, this process involves eight membrane proteins encoded by the ccmABCDEFGH operon. CcmE binds heme covalently and transfers it to apocytochromes c in the presence of other Ccm proteins. CcmC is necessary and sufficient to incorporate heme into CcmE. Here, we report that the CcmC protein directly interacts with heme. We further show that CcmC co-immunoprecipitates with CcmE. CcmC contains two conserved histidines and a signature sequence, the so-called tryptophan-rich motif, which is the only element common to cytochrome c maturation proteins of bacteria, archae, plant mitochondria, and chloroplasts. We report that mutational changes of these motifs affecting the function of CcmC in cytochrome c maturation do not influence heme binding of CcmC. However, the mutants are defective in the CcmC-CcmE interaction, suggesting that these motifs are involved in the formation of a CcmC-CcmE complex. We propose that CcmC, CcmE, and heme interact directly with each other, establishing a periplasmic heme delivery pathway for cytochrome c maturation.
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Abstract
Histone H2A.Z is structurally and functionally distinct from the major H2As. To understand the function of H2A.Z acetylation, we performed a mutagenic analysis of the six acetylated lysines in the N-terminal tail of Tetrahymena H2A.Z. Tetrahymena cannot survive with arginines at all six sites. Retention of one acetylatable lysine is sufficient to provide the essential function of H2A.Z acetylation. This essential function can be mimicked by deleting the region encompassing all six sites, or by mutations that reduce the positive charge of the N terminus at the acetylation sites themselves, or at other sites in the tail. These properties argue that the essential function of H2A.Z acetylation is to modify a "charge patch" by reducing the charge of the tail.
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Ferretti JJ, McShan WM, Ajdic D, Savic DJ, Savic G, Lyon K, Primeaux C, Sezate S, Suvorov AN, Kenton S, Lai HS, Lin SP, Qian Y, Jia HG, Najar FZ, Ren Q, Zhu H, Song L, White J, Yuan X, Clifton SW, Roe BA, McLaughlin R. Complete genome sequence of an M1 strain of Streptococcus pyogenes. Proc Natl Acad Sci U S A 2001; 98:4658-63. [PMID: 11296296 PMCID: PMC31890 DOI: 10.1073/pnas.071559398] [Citation(s) in RCA: 661] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 1,852,442-bp sequence of an M1 strain of Streptococcus pyogenes, a Gram-positive pathogen, has been determined and contains 1,752 predicted protein-encoding genes. Approximately one-third of these genes have no identifiable function, with the remainder falling into previously characterized categories of known microbial function. Consistent with the observation that S. pyogenes is responsible for a wider variety of human disease than any other bacterial species, more than 40 putative virulence-associated genes have been identified. Additional genes have been identified that encode proteins likely associated with microbial "molecular mimicry" of host characteristics and involved in rheumatic fever or acute glomerulonephritis. The complete or partial sequence of four different bacteriophage genomes is also present, with each containing genes for one or more previously undiscovered superantigen-like proteins. These prophage-associated genes encode at least six potential virulence factors, emphasizing the importance of bacteriophages in horizontal gene transfer and a possible mechanism for generating new strains with increased pathogenic potential.
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Ren Q, Murphy SE, Zheng Z, Lazarus P. O-Glucuronidation of the lung carcinogen 4-(methylnitrosamino)-1- (3-pyridyl)-1-butanol (NNAL) by human UDP-glucuronosyltransferases 2B7 and 1A9. Drug Metab Dispos 2000; 28:1352-60. [PMID: 11038164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone and its major metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), are potent lung carcinogens in animals. UGT-mediated O-glucuronidation of NNAL is an important detoxification pathway for these carcinogens. To better characterize this pathway in humans, we screened a series of UGT-overexpressing cell lines and baculosome preparations for their ability to O-glucuronidate NNAL and examined multiple human liver and lung specimens for NNAL-glucuronidating activity and their levels of expression of NNAL-glucuronidating UGTs. Human liver microsomal fractions exhibited significant levels of NNAL-glucuronidating activity, with the NNAL-Gluc II diastereomer formed at a rate 3.4 times that observed for NNAL-Gluc I. As with liver microsomal fractions, NNAL-Gluc II was the major diastereomer formed by homogenates from UGT2B7-overexpressing HK293 cells or UGT2B7-overexpressing baculosomes; the major diastereomer formed by homogenates from UGT1A9-overexpressing V79 cells was NNAL-Gluc I. No significant O-glucuronidating activity of NNAL was detected in UGT1A1-, UGT1A4-, UGT1A6-, UGT2B4-, or UGT2B15-overexpressing HK293 or V79 cell homogenates, or in UGT1A1-, UGT1A3-, UGT1A7-, or UGT1A10-overexpressing baculosomes. Significant levels of UGT2B7 mRNA were detected by reverse transcriptase-polymerase chain reaction in human liver and at low levels in human lung specimens. UGT1A9 mRNA was detected in liver but not in lung. These results suggest that although both UGT2B7 and UGT1A9 play an important role in the overall glucuronidation of NNAL in humans, UGT2B7 potentially plays an important role in the detoxification of NNAL in the lung.
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Siniscalco M, Robledo R, Orru S, Contu L, Yadav P, Ren Q, Lai H, Roe B. A plea to search for deletion polymorphism through genome scans in populations. Trends Genet 2000; 16:435-7. [PMID: 11203137 DOI: 10.1016/s0168-9525(00)02101-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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