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Journal articles on the topic 'AprX gene'

Author: Grafiati
Published: 9 March 2023
Last updated: 11 March 2023

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1

Liao, Ching-Hsing, and Daniel E. McCallus. "Biochemical and Genetic Characterization of an Extracellular Protease from Pseudomonas fluorescensCY091." Applied and Environmental Microbiology 64, no. 3 (March 1, 1998): 914–21. http://dx.doi.org/10.1128/aem.64.3.914-921.1998.

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ABSTRACT Pseudomonas fluorescens CY091 cultures produce an extracellular protease with an estimated molecular mass of 50 kDa. Production of this enzyme (designated AprX) was observed in media containing CaCl2 or SrCl2 but not in media containing ZnCl2, MgCl2, or MnCl2. The requirement of Ca2+ (or Sr2+) for enzyme production was concentration dependent, and the optimal concentration for production was determined to be 0.35 mM. Following ammonium sulfate precipitation and ion-exchange chromatography, the AprX in the culture supernatant was purified to near electrophoretic homogeneity. Over 20% of the enzyme activity was retained in the AprX sample which had been heated in boiling water for 10 min, indicating that the enzyme is highly resistant to heat inactivation. The enzyme activity was almost completely inhibited in the presence of 1 mM 1,10-phenanthroline, but only 30% of the activity was inhibited in the presence of 1 mM EGTA. The gene encoding AprX was cloned from the genome of P. fluorescens CY091 by isolating cosmid clones capable of restoring the protease production in a nonproteolytic mutant of strain CY091. The genomic region of strain CY091 containing the aprX gene was located within a 7.3-kb DNA fragment. Analysis of the complete nucleotide sequence of this 7.3-kb fragment revealed the presence of a cluster of genes required for the production of extracellular AprX inP. fluorescens and Escherichia coli. The AprX protein showed 50 to 60% identity in amino acid sequence to the related proteases produced by Pseudomonas aeruginosa andErwinia chrysanthemi. Two conserved sequence domains possibly associated with Ca2+ and Zn2+ binding were identified. Immediately adjacent to the aprXstructural gene, a gene (inh) encoding a putative protease inhibitor and three genes (aprD, aprE, andaprF), possibly required for the transport of AprX, were also identified. The organization of the gene cluster involved in the synthesis and secretion of AprX in P. fluorescens CY091 appears to be somewhat different from that previously demonstrated inP. aeruginosa and E. chrysanthemi.
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2

Longhi, Rosana De, Samera Rafaela Bruzaroski, Josiane Ito Eleodoro, Regina Celia Poli-Frederico, Rafael Fagnani, Agostinho Ludovico, and Elsa Helena Walter de Santana. "Presence of aprX gene in Pseudomonas spp. from refrigerated raw milk and their proteolytic ability." Semina: Ciências Agrárias 41, no. 4 (May 13, 2020): 1421. http://dx.doi.org/10.5433/1679-0359.2020v41n4p1421.

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This study aimed to determine the frequency of Pseudomonas fluorescens, P. putida, and P. aeruginosa in refrigerated raw milk; their proteolytic potential; and your association with the aprX gene. Of the 173 isolates confirmed as belonging to Pseudomonas spp., 37% were P. fluorescens, 25.4% P. putida, and none belongs to P. aeruginosa. The aprX gene was distributed proportionally between P. putida (68%) and P. fluorescens (75%), but it was not associated with low or high proteolytic potential in both species. P. putida (16) and P. fluorescens (14) isolates with no aprX gene identified also had proteolytic potential. Considering the synthesis of proteases other than AprX by the isolates under study, we concluded that P. fluorescens and P. putida represented 62.4% of the Pseudomonas genus, with high probability of having the aprX gene and proteolytic potential. However, there was no association between the deteriorating potential with the presence of the aprX gene.
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3

Zarei, Mehdi, Hooriyeh Mohammadpour, Darioush Gharibi, and Mahdi Pourmahdi Borujeni. "Identification of Pseudomonas jessenii and Pseudomonas gessardii as the most proteolytic Pseudomonas isolates in Iranian raw milk and their impact on stability of sterilized milk during storage." Journal of Dairy Research 87, no. 3 (August 2020): 368–74. http://dx.doi.org/10.1017/s0022029920000709.

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AbstractIdentification of the most proteolytic Pseudomonas strains that can produce heat-resistant proteases and contribute to the Ultra High Temperature (UHT) milk destabilization is of great interest. In the present study, among the 146 Pseudomonas isolates that encoded the aprX gene, five isolates with the highest proteolytic activity were selected and identified based on 16S rRNA, rpoD and gyrB gene sequences data. The identification results were confirmed by phylogenetic analysis based on multilocus sequence analysis and identified the representative isolates as P. jessenii (two isolates) and P. gessardii (three isolates). Casein zymography demonstrated the ability of these species to produce heat-resistant enzymes, AprX, with molecular mass of about 48 kDa during storage at 7° C for 72 h. In sterilized milk samples, the residual activity of AprX caused a considerable enhancement in the degree of protein hydrolysis, non-protein nitrogen and non-casein nitrogen contents of the samples during a two-month storage. This enhancement was slightly higher in samples containing enzyme produced by P. jessenii compared to P. gessardii ones, resulting in earlier onset of sterilized milk destabilization. Hence, this study revealed that P. jessenii and P. gessardii can play a considerable role in deterioration of Iranian commercial long-life milk.
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4

Teider Junior, Pedro I., José C. Ribeiro Júnior, Eric H. Ossugui, Ronaldo Tamanini, Juliane Ribeiro, Gislaine A. Santos, Amauri A. Alfieri, and Vanerli Beloti. "Pseudomonas spp. and other psychrotrophic microorganisms in inspected and non-inspected Brazilian Minas Frescal cheese: proteolytic, lipolytic and AprX production potential." Pesquisa Veterinária Brasileira 39, no. 10 (October 2019): 807–15. http://dx.doi.org/10.1590/1678-5150-pvb-6037.

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ABSTRACT: The most consumed cheese in Brazil, Minas Frescal cheese (MFC) is highly susceptible to microbial contamination and clandestine production and commercialization can pose a risk to consumer health. The storage of this fresh product under refrigeration, although more appropriate, may favor the growth of spoilage psychrotrophic bacteria. The objective of this study was to quantify and compare Pseudomonas spp. and other psychrotrophic bacteria in inspected and non-inspected MFC samples, evaluate their lipolytic and proteolytic activities and their metalloprotease production potentials. Twenty MFC samples were evaluated: 10 inspected and 10 non-inspected. Counts of psychrotrophic bacteria and Pseudomonas spp., evaluation of the proteolytic and lipolytic potential of the isolates, and identification of potential producers of alkaline metalloprotease (AprX) were assessed. The mean total psychrotrophic counts were 1.07 (±2.18) × 109CFU/g in the inspected samples and 4.5 (±5.86) × 108CFU/g in the non-inspected, with no significant difference (p=0.37). The average score of Pseudomonas spp. was 6.86 (±18.6) × 105 and 2.08 (±3.65) × 106 CFU/g for the inspected and non-inspected MFC samples, respectively, with no significant difference (p=0.1). Pseudomonas spp. represented 0.06% and 0.004% of psychrotrophic bacteria found in inspected and non-inspected MFC samples, respectively. Collectively, 694 psychrotrophic strains and 47Pseudomonas spp. were isolated, of which 59.9% and 68.1% were simultaneously proteolytic and lipolytic, respectively. Of the 470 psychrotrophs isolated from inspected and 224 from non-inspected cheese samples, 5.74% and 2.23% contained aprX, respectively, while 100 and 86.96% of the Pseudomonas spp. isolates in inspected and non-inspected cheese samples contained the gene. The production potential of AprX did not, however, determine the proteolytic activity on plates of these isolates under the conditions evaluated in this study. Of total, 65.63% of the psychrotrophs that contained aprX gene were confirmed as Pseudomonas spp., using genus-specific PCR. Phylogenetic analysis of the 16S rRNA gene of the other psychrotrophs that were potential producers of AprX identified them as Serratia spp. (n=7), Raoultella ornithinolytica (n=1), and Acinetobacter schindleri (n=1) in the inspected samples and Psychrobacter sanguinis (n=1) and Leuconostoc mesenteroides (n=1) in the non-inspected samples. The production conditions of Brazilian MFC of these samples, while meeting the legal determinations, are not sufficient to control Pseudomonas and other spoilage-related psychrotrophs. Thus, stricter hygienic measures are required during the formal production of this type of cheese.
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5

Maier, Christopher, Katharina Hofmann, Christopher Huptas, Siegfried Scherer, Mareike Wenning, and Genia Lücking. "Simultaneous quantification of the most common and proteolytic Pseudomonas species in raw milk by multiplex qPCR." Applied Microbiology and Biotechnology 105, no. 4 (February 2021): 1693–708. http://dx.doi.org/10.1007/s00253-021-11109-0.

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Abstract The heat-stable peptidase AprX, secreted by psychrotolerant Pseudomonas species in raw milk, is a major cause of destabilization and premature spoilage of ultra-high temperature (UHT) milk and milk products. To enable rapid detection and quantification of seven frequent and proteolytic Pseudomonas species (P. proteolytica, P. gessardii, P. lactis, P. fluorescens, P. protegens, P. lundensis, and P. fragi) in raw milk, we developed two triplex qPCR assays taking into account species-dependent differences in AprX activity. Besides five species-specific hydrolysis probes, targeting the aprX gene, a universal rpoB probe was included in the assay to determine the total Pseudomonas counts. For all six probes, linear regression lines between Cq value and target DNA concentration were obtained in singleplex as well as in multiplex approaches, yielding R2 values of > 0.975 and amplification efficiencies of 85–97%. Moreover, high specificity was determined using genomic DNA of 75 Pseudomonas strains, assigned to 57 species, and 40 other bacterial species as templates in the qPCR. Quantification of the target species and total Pseudomonas counts resulted in linear detection ranges of approx. 103–107 cfu/ml, which correspond well to common Pseudomonas counts in raw milk. Application of the assay using 60 raw milk samples from different dairies showed good agreement of total Pseudomonas counts calculated by qPCR with cell counts derived from cultivation. Furthermore, a remarkably high variability regarding the species composition was observed for each milk sample, whereby P. lundensis and P. proteolytica/P. gessardii were the predominant species detected. Key points • Multiplex qPCR for quantification of seven proteolytic Pseudomonas species and total Pseudomonas counts in raw milk • High specificity and sensitivity via hydrolysis probes against aprX and rpoB • Rapid method to determine Pseudomonas contamination in raw milk and predict spoilage potential
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6

Costa, Nayara Aparecida da Silva, Rafaela da Silva Rodrigues, Antônio Fernandes de Carvalho, and Solimar Gonçalves Machado. "Proteases e lipases produzidas por Pseudomonas: um desafio na indústria de lácteos." Journal of Engineering and Exact Sciences 8, no. 9 (November 10, 2022): 14900–01. http://dx.doi.org/10.18540/jcecvl8iss9pp14900-01e.

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Pseudomonas spp. são comumente relacionadas com a deterioração de produtos lácteos. Algumas espécies desse gênero, além de se multiplicarem em temperaturas de refrigeração, produzem enzimas hidrolíticas responsáveis pela deterioração do leite e seus derivados. A metaloprotease AprX é uma das proteases produzidas por Pseudomonas. Essa enzima, codificada pelo gene aprX, é resistente ao calor e capaz de manter sua atividade mesmo após tratamentos térmicos comumente utilizados na indústria de laticínios, como pasteurização e tratamento UHT (Ultra-high Temperature), resultando em perdas das características sensoriais e em problemas como a gelificação. Algumas cepas de Pseudomonas também podem produzir enzimas lipolíticas termorresistentes. Essas enzimas catalisam a hidrólise de triacilgliceróis, resultando na liberação de ácidos graxos associados à deterioração de muitos alimentos. Esses ácidos contribuem para o sabor forte, rançoso e de sabão de produtos lácteos. Em vista disso, o objetivo deste trabalho foi destacar, por meio de uma revisão de literatura, os desafios enfrentados pela indústria de lácteos frente às proteases e lipases produzidas pelo gênero Pseudomonas.
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7

Anderson, L. Meadow, Virginia O. Stockwell, and Joyce E. Loper. "An Extracellular Protease of Pseudomonas fluorescens Inactivates Antibiotics of Pantoea agglomerans." Phytopathology® 94, no. 11 (November 2004): 1228–34. http://dx.doi.org/10.1094/phyto.2004.94.11.1228.

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Pseudomonas fluorescens A506 and Pantoea agglomerans strains Eh252 and C9-1 are biological control agents that suppress fire blight, an important disease of pear and apple caused by the bacterium Erwinia amylovora. Pseudomonas fluorescens strain A506 suppresses disease largely through competitive exclusion of E. amylovora on surfaces of blossoms, the primary infection court, whereas Pantoea agglomerans strains Eh252 and C9-1 produce antibiotics that are toxic to E. amylovora. In this study, an extracellular protease produced by A506 is characterized and evaluated for its capacity to inactivate the antibiotics produced by the strains of Pantoea agglomerans. Activity of the extracellular protease was optimal at pH 9 and inhibited by zinc- or calcium-chelators, indicating that the protease is an alkaline metalloprotease. In an agar plate bioassay, partially purified extracellular protease inactivated the antibiotics mccEh252 and herbicolin O, which are produced by Pantoea agglomerans strains Eh252 and C9-1, respectively. Derivatives of A506 deficient in extracellular protease production were obtained by transposon mutagenesis, and the aprX gene encoding the protease was cloned and sequenced. Strain A506 inactivated mccEh252 and herbicolin O in agar plate bioassays, whereas the aprX mutant did not inactivate the antibiotics. Both A506 and the aprX mutant were insensitive to antibiosis by C9-1 and Eh252; thus, the protease was not required to protect A506 from antibiosis. These data highlight a previously unknown role of the extracellular protease produced by Pseudomonas fluorescens A506 in interactions among plant-associated microbes.
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8

Ribeiro Júnior, José C., Pedro I. Teider Junior, André L. M. Oliveira, Edson A. Rios, Ronaldo Tamanini, and Vanerli Beloti. "Proteolytic and lipolytic potential of Pseudomonas spp. from goat and bovine raw milk." Pesquisa Veterinária Brasileira 38, no. 8 (August 2018): 1577–83. http://dx.doi.org/10.1590/1678-5150-pvb-5645.

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ABSTRACT: Pseudomonas, the main genus of gram-negative microorganisms isolated from milk, is psychrotrophic, biofilm-forming, and thermo-resistant deteriorating enzyme producers. The aim of this study was to quantify Pseudomonas spp. in goat’s and cow’s milk produced in the Paraná state, Brazil, to evaluate the deteriorating activity of the isolates at mesophilic and psychrotrophic conditions and to identify, at the species level, the isolates with alkaline metalloprotease (aprX gene) production potential. Microbiological, biochemical and molecular methods were used for isolating, confirming and identifying of isolates. The mean counts were 1.6 (±6.3)x104 and 0.89(±3)x102 CFU/mL for goat and bovine milk samples, respectively, immediately after milking. Of the Pseudomonas colonies isolated from goat milk (n=60), 91.7% showed proteolytic potential when incubated at 35°C/48 h and 80% at 7°C/10 days, and lipolytic potential was observed in 95% of the isolates incubated in mesophilic and 78.3% at refrigeration conditions. From the isolates of bovine milk (n=20), 35% showed proteolytic activity only when incubated at 35°C/48 h, and lipolytic potential was observed in 25% of the isolates incubated at 7°C/10d and 35°C/48h. It was observed that 83.3% and 25% of the isolates genetically confirmed as Pseudomonas spp. of goat and bovine milk showed the potential for alkaline metalloprotease production, with the species P. azotoformans, P. koreensis, P. gessardii, P. monteilii and P. lurida being the most frequent in goat milk and P. aeruginosa the only species identified in cow milk.
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9

Okrent, Rachel A., Anne B. Halgren, Mark D. Azevedo, Jeff H. Chang, Dallice I. Mills, Maciej Maselko, Donald J. Armstrong, Gary M. Banowetz, and Kristin M. Trippe. "Negative regulation of germination-arrest factor production in Pseudomonas fluorescens WH6 by a putative extracytoplasmic function sigma factor." Microbiology 160, no. 11 (November 1, 2014): 2432–42. http://dx.doi.org/10.1099/mic.0.080317-0.

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Pseudomonas fluorescens WH6 secretes a germination-arrest factor (GAF) that we have identified previously as 4-formylaminooxyvinylglycine. GAF irreversibly inhibits germination of the seeds of numerous grassy weeds and selectively inhibits growth of the bacterial plant pathogen Erwinia amylovora. WH6-3, a mutant that has lost the ability to produce GAF, contains a Tn5 insertion in prtR, a gene that has been described previously in some strains of P. fluorescens as encoding a transmembrane regulator. As in these other pseudomonads, in WH6, prtR occurs immediately downstream of prtI, which encodes a protein homologous to extracytoplasmic function (ECF) sigma factors. These two genes have been proposed to function as a dicistronic operon. In this study, we demonstrated that deletion of prtI in WT WH6 had no effect on GAF production. However, deletion of prtI in the WH6-3 mutant overcame the effects of the Tn5 insertion in prtR and restored GAF production in the resulting double mutant. Complementation of the double prtIR mutant with prtI suppressed GAF production. This overall pattern of prtIR regulation was also observed for the activity of an AprX protease. Furthermore, reverse transcription quantitative real-time PCR analysis demonstrated that alterations in GAF production were mirrored by changes in the transcription of two putative GAF biosynthetic genes. Thus, we concluded that PrtI exerted a negative regulatory effect on GAF production, although the mechanism has not yet been determined. In addition, evidence was obtained that the transcription of prtI and prtR in WH6 may be more complex than predicted by existing models.
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10

Schumann, R. R., C. J. Kirschning, A. Unbehaun, H. P. Aberle, H. P. Knope, N. Lamping, R. J. Ulevitch, and F. Herrmann. "The lipopolysaccharide-binding protein is a secretory class 1 acute-phase protein whose gene is transcriptionally activated by APRF/STAT/3 and other cytokine-inducible nuclear proteins." Molecular and Cellular Biology 16, no. 7 (July 1996): 3490–503. http://dx.doi.org/10.1128/mcb.16.7.3490.

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Acute-phase reactants (APRs) are proteins synthesized in the liver following induction by interleukin-1 (IL-1), IL-6, and glucocorticoids, involving transcriptional gene activation. Lipopolysaccharide-binding protein (LBP) is a recently identified hepatic secretory protein potentially involved in the pathogenesis of sepsis, capable of binding the bacterial cell wall product endotoxin and directing it to its cellular receptor, CD14. In order to examine the transcriptional induction mechanisms by which the LBP gene is activated, we have investigated the regulation of expression of its mRNA in vitro and in vivo as well as the organization of 5' upstream regulatory DNA sequences. We show that induction of LBP expression is transcriptionally regulated and is dependent on stimulation with IL-1beta, IL-6, and dexamethasone. By definition, LBP thus has to be viewed as a class 1 acute-phase protein and represents the first APR identified which is capable of detecting pathogenic bacteria. Furthermore, cloning of the LBP promoter revealed the presence of regulatory elements, including the common APR promoter motif APRE/STAT-3 (acute-phase response element/signal transducer and activator of transcription 3). Luciferase reporter gene assays utilizing LBP promoter truncation and point mutation variants indicated that transcriptional activation of the LBP gene required a functional APRE/STAT-3 binding site downstream of the transcription start site, as well as an AP-1 and a C/EBP (CCAAT enhancer-binding protein) binding site. Gel retardation and supershift assays confirmed that upon cytokine stimulation APRF/STAT-3 binds to its recognition site, leading to strong activation of the LBP gene. Unraveling of the mechanism of transcriptional activation of the LBP gene, involving three known transcription factors, may contribute to our understanding of the acute-phase response and the pathophysiology of sepsis and septic shock.
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11

Ahn, Jung Hoon, Jae Gu Pan, and Joon Shick Rhee. "Identification of the tliDEF ABC Transporter Specific for Lipase in Pseudomonas fluorescensSIK W1." Journal of Bacteriology 181, no. 6 (March 15, 1999): 1847–52. http://dx.doi.org/10.1128/jb.181.6.1847-1852.1999.

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ABSTRACT Pseudomonas fluorescens, a gram-negative psychrotrophic bacterium, secretes a thermostable lipase into the extracellular medium. In our previous study, the lipase of P. fluorescensSIK W1 was cloned and expressed in Escherichia coli, but it accumulated as inactive inclusion bodies. Amino acid sequence analysis of the lipase revealed a potential C-terminal targeting sequence recognized by the ATP-binding cassette (ABC) transporter. The genetic loci around the lipase gene were searched, and a secretory gene was identified. Nucleotide sequencing of an 8.5-kb DNA fragment revealed three components of the ABC transporter, tliD,tliE, and tliF, upstream of the lipase gene,tliA. In addition, genes encoding a protease and a protease inhibitor were located upstream of tliDEF.tliDEF showed high similarity to ABC transporters ofPseudomonas aeruginosa alkaline protease, Erwinia chrysanthemi protease, Serratia marcescens lipase, and Pseudomonas fluorescens CY091 protease.tliDEF and the lipase structural gene in a single operon were sufficient for E. coli cells to secrete the lipase. In addition, E. coli harboring the lipase gene secreted the lipase by complementation of tliDEF in a different plasmid. The ABC transporter of P. fluorescenswas optimally functional at 20 and 25°C, while the ABC transporter,aprD, aprE, and aprF, of P. aeruginosa secreted the lipase irrespective of temperature between 20 and 37°C. These results demonstrated that the lipase is secreted by the P. fluorescens SIK W1 ABC transporter, which is organized as an operon with tliA, and that its secretory function is temperature dependent.
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12

Pel, Michiel J. C., Anja J. H. van Dijken, Bart W. Bardoel, Michael F. Seidl, Sjoerd van der Ent, Jos A. G. van Strijp, and Corné M. J. Pieterse. "Pseudomonas syringae Evades Host Immunity by Degrading Flagellin Monomers with Alkaline Protease AprA." Molecular Plant-Microbe Interactions® 27, no. 7 (July 2014): 603–10. http://dx.doi.org/10.1094/mpmi-02-14-0032-r.

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Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant pathogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantly less virulent on both tomato and Arabidopsis thaliana. Moreover, infiltration of A. thaliana Col-0 leaves with DC3000 ΔaprA evoked a significantly higher level of expression of the defense-related genes FRK1 and PR-1 than did wild-type DC3000. In the flagellin receptor mutant fls2, pathogen virulence and defense-related gene activation did not differ between DC3000 and DC3000 ΔaprA. Together, these results suggest that AprA of DC3000 is important for evasion of recognition by the FLS2 receptor, allowing wild-type DC3000 to be more virulent on its host plant than AprA-deficient DC3000 ΔaprA. To provide further evidence for the role of DC3000 AprA in host immune evasion, we overexpressed the AprA inhibitory peptide AprI of DC3000 in A. thaliana to counteract the immune evasive capacity of DC3000 AprA. Ectopic expression of aprI in A. thaliana resulted in an enhanced level of resistance against wild-type DC3000, while the already elevated level of resistance against DC3000 ΔaprA remained unchanged. Together, these results indicate that evasion of host immunity by the alkaline protease AprA is important for full virulence of strain DC3000 and likely acts by preventing flagellin monomers from being recognized by its cognate immune receptor.
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Firoved, Aaron M., and Vojo Deretic. "Microarray Analysis of Global Gene Expression in Mucoid Pseudomonas aeruginosa." Journal of Bacteriology 185, no. 3 (February 1, 2003): 1071–81. http://dx.doi.org/10.1128/jb.185.3.1071-1081.2003.

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ABSTRACT Pseudomonas aeruginosa is the dominant pathogen causing chronic respiratory infections in cystic fibrosis (CF). After an initial phase characterized by intermittent infections, a chronic colonization is established in CF upon the conversion of P. aeruginosa to the mucoid, exopolysaccharide alginate-overproducing phenotype. The emergence of mucoid P. aeruginosa in CF is associated with respiratory decline and poor prognosis. The switch to mucoidy in most CF isolates is caused by mutations in the mucA gene encoding an anti-sigma factor. The mutations in mucA result in the activation of the alternative sigma factor AlgU, the P. aeruginosa ortholog of Escherichia coli extreme stress sigma factor σE. Because of the global nature of the regulators of mucoidy, we have hypothesized that other genes, in addition to those specific for alginate production, must be induced upon conversion to mucoidy, and their production may contribute to the pathogenesis in CF. Here we applied microarray analysis to identify on the whole-genome scale those genes that are coinduced with the AlgU sigmulon upon conversion to mucoidy. Gene expression profiles of AlgU-dependent conversion to mucoidy revealed coinduction of a specific subset of known virulence determinants (the major protease elastase gene, alkaline metalloproteinase gene aprA, and the protease secretion factor genes aprE and aprF) or toxic factors (cyanide synthase) that may have implications for disease in CF. Analysis of promoter regions of the most highly induced genes (>40-fold, P ≤ 10−4) revealed a previously unrecognized, putative AlgU promoter upstream of the osmotically inducible gene osmE. This newly identified AlgU-dependent promoter of osmE was confirmed by mapping the mRNA 5′ end by primer extension. The recognition of genes induced in mucoid P. aeruginosa, other than those associated with alginate biosynthesis, reported here revealed the identity of previously unappreciated factors potentially contributing to the morbidity and mortality caused by mucoid P. aeruginosa in CF.
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14

Logan, Malcolm, James F. Martin, Andras Nagy, Corrinne Lobe, Eric N. Olson, and Clifford J. Tabin. "Expression of Cre recombinase in the developing mouse limb bud driven by aPrxl enhancer." genesis 33, no. 2 (May 31, 2002): 77–80. http://dx.doi.org/10.1002/gene.10092.

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15

Schultz, David J., Sunita K. Agarwal, and Dennis A. Schaff. "APRT EXPRESSION IN PLANTS." HortScience 27, no. 11 (November 1992): 1160g—1161. http://dx.doi.org/10.21273/hortsci.27.11.1160g.

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Adenine Phosphoribosyltransferase (APRT, EC 2.4.2.7) is an enzyme in the adenine salvage pathway. This enzyme is a catalyst for the conversion of adenine and phosphoribosyl pyrophosphate (PRPP) to adenosine monophosphate (AMP) and inorganic phosphate (PPi). We are using the APRT gene to develop a gene transfer selection system in plants because the APRT gene has been shown to be expressed in numerous plant families, the gene is small (approximately 3 kilobases), the enzyme pathway is well characterized, and positive selection systems are readily available for the presence or absence of the functional APRT protein. Additionally, an APRT assay system has been worked out for the detection of the protein product. In order to develop a gene transfer selection system, we are currently isolating the APRT cDNA clone from Glycine max L. (Soybean). The initial step of this research was to show what tissues of soybean the enzyme activity is found in by using the APRT assay. This assay showed that the enzyme is being expressed in the embryo, radicle, and developing seeds. Furthermore, the assay showed that there is no APRT activity found in immature or mature leaves of soybean. This may be due to an inhibitor in the leaf crude extract. When crude extracts of leaves and developing seeds are mixed in equal volumes, no APRT activity was detected in contrast to the half activity of developing seeds which was expected. Currently, our research has focused on isolating a fragment of the APRT gene from genomic DNA using the polymerase chain reaction (PCR). This fragment will then be used to isolate the cDNA clone from a Lambda Zap II cDNA library made from developing seeds.
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16

Wang, Q., and M. W. Taylor. "Correction of a deletion mutant by gene targeting with an adenovirus vector." Molecular and Cellular Biology 13, no. 2 (February 1993): 918–27. http://dx.doi.org/10.1128/mcb.13.2.918-927.1993.

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The usefulness of adenovirus type 5 as a vector for homologous recombination was examined in CHO cells by using the adenine phosphoribosyltransferase (aprt) gene. Infection of a hemizygous CHO APRT- cell line containing a 3-bp deletion in exon 5 of the aprt gene with a recombinant adenovirus containing the wild-type gene resulted in restoration of the APRT+ phenotype at a frequency of 10(-5) to 10(-6) per infected cell. A relatively high frequency (approximately 6 to 20%) of the transductants appears to result from a homologous recombination event. The mutation on the chromosomal aprt gene is corrected in the homologous recombinants, and APRT expression is restored to a normal hemizygous level. Neither adenovirus nor exogenous promoter sequences are detected in the homologous recombinants. The remaining transductants result from random integration of the aprt gene with the adenovirus sequence. A number of adenovirus vectors containing different promoter sequences linked to the hamster aprt gene were constructed. A possible role for the promoter region in the homologous recombination event was indicated by the lack of homologous recombination in constructs lacking an active promoter.
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17

Wang, Q., and M. W. Taylor. "Correction of a deletion mutant by gene targeting with an adenovirus vector." Molecular and Cellular Biology 13, no. 2 (February 1993): 918–27. http://dx.doi.org/10.1128/mcb.13.2.918.

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The usefulness of adenovirus type 5 as a vector for homologous recombination was examined in CHO cells by using the adenine phosphoribosyltransferase (aprt) gene. Infection of a hemizygous CHO APRT- cell line containing a 3-bp deletion in exon 5 of the aprt gene with a recombinant adenovirus containing the wild-type gene resulted in restoration of the APRT+ phenotype at a frequency of 10(-5) to 10(-6) per infected cell. A relatively high frequency (approximately 6 to 20%) of the transductants appears to result from a homologous recombination event. The mutation on the chromosomal aprt gene is corrected in the homologous recombinants, and APRT expression is restored to a normal hemizygous level. Neither adenovirus nor exogenous promoter sequences are detected in the homologous recombinants. The remaining transductants result from random integration of the aprt gene with the adenovirus sequence. A number of adenovirus vectors containing different promoter sequences linked to the hamster aprt gene were constructed. A possible role for the promoter region in the homologous recombination event was indicated by the lack of homologous recombination in constructs lacking an active promoter.
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18

BAKIR, Melike, and Cebrail YILDIRIM. "Isolation and expression analysis of ascorbate peroxidase (APX) gene in lentil (Lens culinaris Medik.) under drought stress conditions." Ege Üniversitesi Ziraat Fakültesi Dergisi 59, no. 3 (September 30, 2022): 439–47. http://dx.doi.org/10.20289/zfdergi.1007041.

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Objective: The objective of this study was to isolate partial cDNA that belongs to the ascorbate peroxidase (APX) gene of lentil (Lens culinaris Medik.) and to express LcAPX gene in lentil seedlings under drought stress conditions. Material and Methods: To identify the relationships between drought stress and LcAPX gene expression, lentil seedlings grown for 2 weeks were subjected to drought stress through not irrigating for 6, 13, and 20 days. Effects of drought stress were determined by measuring the stem relative water content (RWC). Gene expression changes in lentil seedlings were determined with real-time RT-qPCR. Results: The LcAPX gene expression levels of both drought-tolerant Firat-87 and drought-sensitive Ozbek cultivars varied with the severity of drought stress. The gene expression of LcAPX reached the highest level in Firat-87 cultivar on the 6th day, whereas a significant increase was observed only on the 20th day of the Ozbek cultivar, and this increase was relatively low as compared to the Fırat-87 cultivar. Conclusion: From the study conducted, it was concluded that time-dependent changes of the expression of LcAPX gene indicates that LcAPX gene had a highly specific gene expression profile and complex regulation in lentil drought response.
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19

Paulin, R. P., T. Ho, H. J. Balzer, and R. Holliday. "Gene Silencing by DNA Methylation and Dual Inheritance in Chinese Hamster Ovary Cells." Genetics 149, no. 2 (June 1, 1998): 1081–88. http://dx.doi.org/10.1093/genetics/149.2.1081.

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Abstract Chinese hamster ovary (CHO) cells strain D422, which has one copy of the adenine phosphoribosyl transferase (APRT) gene, were permeabilized by electroporation and treated with 5-methyl deoxycytidine triphosphate. Cells with a silenced APRT gene were selected on 2, 6-diaminopurine. Colonies were isolated and shown to be reactivated to APRT+ by 5-aza-cytidine and by selection in medium containing adenine, aminopterin and thymidine. Genomic DNA was prepared from eight isolates of independent origin and subjected to bisulphite treatment. This deaminates cytosine to uracil in single-stranded DNA but does not deaminate 5-methyl cytosine. PCR, cloning and sequencing revealed the methylation pattern of CpG doublets in the promoter region of the APRT− gene, whereas the active APRT gene had nonmethylated DNA. CHO strain K1, which has two copies of the APRT+ gene, could also be silenced by the same procedure but at a lower frequency. The availability of the 5-methyl dCTP-induced silencing, 5-aza-CR and a standard mutagen, ethyl methane sulphonate, makes it possible to follow concomitantly the inheritance of active, mutant or silenced gene copies. This analysis demonstrates “dual inheritance” at the APRT locus in CHO cells.
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20

Hidaka, Yuji, Susan A. Tarlé, Timothy E. O'Toole, William N. Kelley, and Thomas D. Palella. "Nucleotide sequence of the human APRT gene." Nucleic Acids Research 15, no. 21 (1987): 9086. http://dx.doi.org/10.1093/nar/15.21.9086.

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21

Scheerer, J. B., and G. M. Adair. "Homology dependence of targeted recombination at the Chinese hamster APRT locus." Molecular and Cellular Biology 14, no. 10 (October 1994): 6663–73. http://dx.doi.org/10.1128/mcb.14.10.6663-6673.1994.

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Using simple linear fragments of the Chinese hamster adenine phosphoribosyltransferase (APRT) gene as targeting vectors, we have investigated the homology dependence of targeted recombination at the endogenous APRT locus in Chinese hamster ovary (CHO) cells. We have examined the effects of varying either the overall length of targeting sequence homology or the length of 5' or 3' flanking homology on both the frequency of targeted homologous recombination and the types of recombination events that are obtained. We find an exponential (logarithmic) relationship between length of APRT targeting homology and the frequency of targeted recombination at the CHO APRT locus, with the frequency of targeted recombination dependent upon both the overall length of targeting homology and the length of homology flanking each side of the target gene deletion. Although most of the APRT+ recombinants analyzed reflect simple targeted replacement or conversion of the target gene deletion, a significant fraction appear to have arisen by target gene-templated extension and correction of the targeting fragment sequences. APRT fragments with limited targeting homology flanking one side of the target gene deletion yield proportionately fewer target gene conversion events and proportionately more templated extension and vector correction events than do fragments with more substantial flanking homology.
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22

Scheerer, J. B., and G. M. Adair. "Homology dependence of targeted recombination at the Chinese hamster APRT locus." Molecular and Cellular Biology 14, no. 10 (October 1994): 6663–73. http://dx.doi.org/10.1128/mcb.14.10.6663.

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Using simple linear fragments of the Chinese hamster adenine phosphoribosyltransferase (APRT) gene as targeting vectors, we have investigated the homology dependence of targeted recombination at the endogenous APRT locus in Chinese hamster ovary (CHO) cells. We have examined the effects of varying either the overall length of targeting sequence homology or the length of 5' or 3' flanking homology on both the frequency of targeted homologous recombination and the types of recombination events that are obtained. We find an exponential (logarithmic) relationship between length of APRT targeting homology and the frequency of targeted recombination at the CHO APRT locus, with the frequency of targeted recombination dependent upon both the overall length of targeting homology and the length of homology flanking each side of the target gene deletion. Although most of the APRT+ recombinants analyzed reflect simple targeted replacement or conversion of the target gene deletion, a significant fraction appear to have arisen by target gene-templated extension and correction of the targeting fragment sequences. APRT fragments with limited targeting homology flanking one side of the target gene deletion yield proportionately fewer target gene conversion events and proportionately more templated extension and vector correction events than do fragments with more substantial flanking homology.
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23

Baba, Yasuhiko, Ryan J. Uitti, Kevin B. Boylan, Yoshinari Uehara, Tatsuo Yamada, Matthew J. Farrer, Elizabeth Couchon, Sat Dev Batish, and Zbigniew K. Wszolek. "Aprataxin (APTX) gene mutations resembling multiple system atrophy." Parkinsonism & Related Disorders 13, no. 3 (April 2007): 139–42. http://dx.doi.org/10.1016/j.parkreldis.2006.08.010.

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24

Siddiqui, Imran Ali, Dieter Haas, and Stephan Heeb. "Extracellular Protease of Pseudomonas fluorescens CHA0, a Biocontrol Factor with Activity against the Root-Knot Nematode Meloidogyne incognita." Applied and Environmental Microbiology 71, no. 9 (September 2005): 5646–49. http://dx.doi.org/10.1128/aem.71.9.5646-5649.2005.

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ABSTRACT In Pseudomonas fluorescens CHA0, mutation of the GacA-controlled aprA gene (encoding the major extracellular protease) or the gacA regulatory gene resulted in reduced biocontrol activity against the root-knot nematode Meloidogyne incognita during tomato and soybean infection. Culture supernatants of strain CHA0 inhibited egg hatching and induced mortality of M. incognita juveniles more strongly than did supernatants of aprA and gacA mutants, suggesting that AprA protease contributes to biocontrol.
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25

Ogura, Mitsuo, Atsushi Matsuzawa, Hirofumi Yoshikawa, and Teruo Tanaka. "Bacillus subtilis SalA (YbaL) Negatively Regulates Expression of scoC, Which Encodes the Repressor for the Alkaline Exoprotease Gene, aprE." Journal of Bacteriology 186, no. 10 (May 15, 2004): 3056–64. http://dx.doi.org/10.1128/jb.186.10.3056-3064.2004.

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ABSTRACT During the course of screening for exoprotease-deficient mutants among Bacillus subtilis gene disruptants, a strain showing such a phenotype was identified. The locus responsible for this phenotype was the previously unknown gene ybaL, which we renamed salA. The predicted gene product encoded by salA belongs to the Mrp family, which is widely conserved among archaea, prokaryotes, and eukaryotes. Disruption of salA resulted in a decrease in the expression of a lacZ fusion of the aprE gene encoding the major extracellular alkaline protease. The decrease was recovered by the cloned salA gene on a plasmid, demonstrating that the gene is involved in aprE expression. Determination of the cis-acting region of SalA on the upstream region of aprE, together with epistatic analyses with scoC, abrB, and spo0A mutations that also affect aprE expression, suggested that salA deficiency affects aprE-lacZ expression through the negative regulator ScoC. Northern and reverse transcription-PCR analyses revealed enhanced levels of scoC transcripts in the salA mutant cells in the transition and early stationary phases. Concomitant with these observations, larger amounts of the ScoC protein were detected in the mutant cells by Western analysis. From these results we conclude that SalA negatively regulates scoC expression. It was also found that the expression of a salA-lacZ fusion was increased by salA deficiency, suggesting that salA is autoregulated.
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26

NAGAO, Kazutaka. "Cloning and structural analysis of mouse Apex gene encoding the major apurinic/apyrimidinic endonuclease." Okayama Igakkai Zasshi (Journal of Okayama Medical Association) 106, no. 7-8 (1994): 717–30. http://dx.doi.org/10.4044/joma1947.106.7-8_717.

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27

Park, J. H., and M. W. Taylor. "Analysis of signals controlling expression of the Chinese hamster ovary aprt gene." Molecular and Cellular Biology 8, no. 6 (June 1988): 2536–44. http://dx.doi.org/10.1128/mcb.8.6.2536-2544.1988.

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The 5' end of the Chinese hamster ovary aprt gene was sequenced and transcription start sites were determined by both S1 nuclease protection and primer extension assays. Deletion mutants covering the same area were constructed, and adenine phosphoribosyltransferase (APRT) or chloramphenicol acetyltransferase (CAT) activity was measured by transient-expression assays. The aprt gene uses a single cluster of transcription start sites and lacks consensus sequences such as TATA and CCAAT, which are general components of eucaryotic promoters. The 5' deletion mutations of the promoter sequences demonstrated that (i) there is no decrease in either APRT activity or transcription extending to position -89 (relative to the main transcription start site); (ii) an additional 29-base-pair (bp) deletion decreases APRT activity and transcription twofold; and (iii) a deletion past the transcription start sites (P5' delta +27) abolishes both APRT activity and transcription, indicating that a 60-bp fragment immediately upstream of the main transcription start site is involved in basic transcription and a 29-bp fragment just upstream of the 60 bp-fragment stimulates transcription twofold. The 3' deletion mutations showed that a deletion of a 61-bp fragment in the 5' leader and coding sequence abolishes the efficient translation of an aprt-CAT gene transcript. In addition, there are two polyadenylation signals at the genomic 3' end, with the proximal one being sufficient for functional polyadenylation.
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28

Park, J. H., and M. W. Taylor. "Analysis of signals controlling expression of the Chinese hamster ovary aprt gene." Molecular and Cellular Biology 8, no. 6 (June 1988): 2536–44. http://dx.doi.org/10.1128/mcb.8.6.2536.

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The 5' end of the Chinese hamster ovary aprt gene was sequenced and transcription start sites were determined by both S1 nuclease protection and primer extension assays. Deletion mutants covering the same area were constructed, and adenine phosphoribosyltransferase (APRT) or chloramphenicol acetyltransferase (CAT) activity was measured by transient-expression assays. The aprt gene uses a single cluster of transcription start sites and lacks consensus sequences such as TATA and CCAAT, which are general components of eucaryotic promoters. The 5' deletion mutations of the promoter sequences demonstrated that (i) there is no decrease in either APRT activity or transcription extending to position -89 (relative to the main transcription start site); (ii) an additional 29-base-pair (bp) deletion decreases APRT activity and transcription twofold; and (iii) a deletion past the transcription start sites (P5' delta +27) abolishes both APRT activity and transcription, indicating that a 60-bp fragment immediately upstream of the main transcription start site is involved in basic transcription and a 29-bp fragment just upstream of the 60 bp-fragment stimulates transcription twofold. The 3' deletion mutations showed that a deletion of a 61-bp fragment in the 5' leader and coding sequence abolishes the efficient translation of an aprt-CAT gene transcript. In addition, there are two polyadenylation signals at the genomic 3' end, with the proximal one being sufficient for functional polyadenylation.
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29

Block, Timothy, John Brzykcy, Nicholas Hastie, and Robert G. Hughes Jr. "Genetic linkage but independent expression of functional HSV-1 tk and mammalian aprt genes after cotransfer to L cells." Canadian Journal of Microbiology 31, no. 4 (April 1, 1985): 311–16. http://dx.doi.org/10.1139/m85-059.

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DNA-mediated gene transformation of mouse Ltk−aprt−hprt− cells was used to obtain stable, doubly selected transformants simultaneously expressing herpes virus thymidine kinase (TK) and mammalian adenine phosphoribosyltransferase (APRT). Cotransformants occurred at a frequency of 5 × 10−6, a similar frequency for the transfer of the aprt marker has been previously observed. Isozyme and Southern blot analysis show that the TK and APRT expressed in these transformants resulted from gene transfer. For one stable cotransformant, [3H]thymidine ([3H]TdR) selection against TK activity resulted in the loss of APRT activity as well, suggesting that these genes had become genetically linked together. Similarly selection against APRT expression resulted in the loss of a subset of the transferred herpes simplex virus tk genes. 5-Bromodeoxyuridine (BUdR) selected TK− variants differed from [3H]TdR selected TK− variants, in that they retained tk genes. However, BUdR-selected variants expressed full levels of APRT. Therefore, even though the transferred tk and aprt genes had become genetically linked together, they were, in this case, independently expressed since these cells were phenotypically TK− and APRT+.
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30

Merrihew, R. V., K. Marburger, S. L. Pennington, D. B. Roth, and J. H. Wilson. "High-frequency illegitimate integration of transfected DNA at preintegrated target sites in a mammalian genome." Molecular and Cellular Biology 16, no. 1 (January 1996): 10–18. http://dx.doi.org/10.1128/mcb.16.1.10.

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To examine the mechanisms of recombination governing the illegitimate integration of transfected DNA into a mammalian genome, we developed a cell system that selects for integration events in defined genomic regions. Cell lines with chromosomal copies of the 3' portion of the adenine phosphoribosyltransferase (APRT) gene (targets) were established. The 5' portion of the APRT gene, which has no homology to the integrated 3' portion, was then electroporated into the target cell lines, and selection for APRT gene function was applied. The reconstruction of the APRT gene was detected at frequencies ranging from less than 10(-7) to 10(-6) per electroporated cell. Twenty-seven junction sequences between the integrated 5' APRT and its chromosomal target were analyzed. They were found to be randomly distributed in a 2-kb region immediately in front of the 3' portion of the APRT gene. The junctions fell into two main classes: those with short homologies (microhomologies) and those with inserted DNA of uncertain origin. Three long inserts were shown to preexist elsewhere in the genome. Reconstructed cell lines were analyzed for rearrangements at the target site by Southern blotting; a variety of simple and complex rearrangements were detected. Similar analysis of individual clones of the parental cell lines revealed analogous types of rearrangement, indicating that the target sites are unstable. Given the high frequency of integration events at these sites, we speculate that transfected DNA may preferentially integrate at unstable mammalian loci. The results are discussed in relation to possible mechanisms of DNA integration.
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31

Phear, G., N. P. Bhattacharyya, and M. Meuth. "Loss of heterozygosity and base substitution at the APRT locus in mismatch-repair-proficient and -deficient colorectal carcinoma cell lines." Molecular and Cellular Biology 16, no. 11 (November 1996): 6516–23. http://dx.doi.org/10.1128/mcb.16.11.6516.

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We determined the nature of mutations occurring at the autosomal APRT locus in mismatch-repair-proficient and -deficient colorectal carcinoma cell lines. The analysis of mutations that result in APRT deficiency in a mismatch-repair-deficient strain of DLD-1 heterozygous for this locus enabled us to measure the rate of loss of the wild-type gene through deletion, recombination, or gene conversion as well as the rate of point mutation. The overall rate of mutation at the APRT locus in DLD-1 was elevated 100-fold compared with the mismatch-repair-proficient colorectal carcinoma cell line SW620. Loss of heterozygosity (LOH) at APRT accounted for only 4 to 9% of mutant strains derived from DLD-1, indicating a rate for these types of events of 4 x 10(-7) to 9 x 10(-7). In SW620 the rate of LOH at APRT was about 10-fold higher. LOH was not found at polymorphic markers within the same chromosome subband as APRT, indicating that only a limited portion of the chromosome was affected by these alterations. Chromosome painting of SWS620 mutants revealed that the loss of APRT occurred together with a substantial portion of the long arm of chromosome 16. Differences in the nature of base substitutions at APRT (e.g., the proportion of mutations resulting from transitions or transversions) in these tumor cell lines were also detected. There was also an important similarity---the presence of a mutant APRT gene with multiple base substitutions that may be the result of some sort of error-prone DNA synthesis.
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32

SADAIE, Yoshito. "secA341Mutation Inhibition of Expression of theBacillus subtilisProtease Gene,aprE." Bioscience, Biotechnology, and Biochemistry 62, no. 9 (January 1998): 1784–87. http://dx.doi.org/10.1271/bbb.62.1784.

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33

Nalbantoglu, J., G. A. Phear, and M. Meuth. "Nucleotide sequence of hamster adenine phosphoribosyl transferase (aprt) gene." Nucleic Acids Research 14, no. 4 (1986): 1914. http://dx.doi.org/10.1093/nar/14.4.1914.

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34

Fieldhouse, Dan, and G. Brian Golding. "The rat adenine phosphoribosyltransferase sequence shows evolutionary rate variation among exons in rodents." Genome 36, no. 6 (December 1, 1993): 1107–10. http://dx.doi.org/10.1139/g93-147.

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The complete genomic sequence of the rat APRT gene is described and compared with published mammalian sequences. The rat APRT gene organization is typical of other rodent APRTs with five exons, one large intron of 993 bp, and three smaller introns averaging 145 bp. Because complete sequences for mouse and Chinese hamster APRT are also known, it is possible to compare the evolutionary rates of change in the exons with those of the introns. The latter provide one possible estimate of underlying rates of change. It is shown that the APRT exons have differential rates of evolution in rodents and have had a recent and rapid burst of substitutions within the mouse lineage. Rates of change in the exons do not appear to be strongly correlated with the rates of change in the introns.Key words: APRT, purine salvage enzymes, rates of evolution, rodent.
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35

Ren, Minhong, Meng-Yun Li, Lin-Qian Lu, Yuan-Sen Liu, Feng-Kun An, Kai Huang, and Zhen Fu. "Arenga pinnata Resistant Starch Modulate Gut Microbiota and Ameliorate Intestinal Inflammation in Aged Mice." Nutrients 14, no. 19 (September 22, 2022): 3931. http://dx.doi.org/10.3390/nu14193931.

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This study aimed to compare the regulatory effects of Arenga pinnata retrograded starch (APRS), Arenga pinnata starch (APS), and whole Arenga pinnata flour (APF) on gut microbiota and improvement of intestinal inflammation in aged mice. APF, APS, and APRS altered gut microbiota composition and exhibited different prebiotic effects. Bifidobacterium showed the greatest increase in feces of aged mice fed APF. The abundance of genus Lachnospiraceae_NK4A136 was highest in the APS group. APRS supplementation led to a greatest increasement in abundance of Lactobacillus, Roseburia, and Faecalibacterium prausnitzii. APRS induced significantly more short-chain fatty acid (SCFAs) production than APF and APS. APF, APS, and APRS treatments improved intestinal inflammation in aged mice and the order of ameliorative effect was APRS > APS > APF. APRS significantly decreased relative mRNA expression of pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) and increased anti-inflammatory cytokines (IL-10). In addition, APF, APS, and APRS significantly downregulated the relative mRNA expression of senescence-associated gene p53 and upregulated the expression of anti-aging gene Sirt1. These results provide potentially useful information about the beneficial effects of Arenga pinnata products on human health.
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36

Jain, Sudhir, Yanna Li, Sai Patil, and Ashok Kumar. "HNF-1α plays an important role in IL-6-induced expression of the human angiotensinogen gene." American Journal of Physiology-Cell Physiology 293, no. 1 (July 2007): C401—C410. http://dx.doi.org/10.1152/ajpcell.00433.2006.

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Angiotensinogen (AGT) is the precursor of one of the most important vasoactive hormone angiotensin II and this gene locus is associated with human essential hypertension. AGT is an acute phase protein and its gene expression is regulated by IL-6. Previous studies have identified three potential STAT-3 binding sites (APREs) located between −160 and −280 of the hAGT gene promoter but only APRE-1 (located between −271 and −279) was shown to be a bonafide enhancer for IL-6-induced promoter activity. We show here that APRE-2, located between −236 and −247, is indeed an HNF-1α-binding site and plays an important role in basal and IL-6 induced promoter activity of this gene. Our chromatin immunoprecipitation (ChIP) assay shows that HNF-1α binds to this region of the hAGT gene promoter and its recruitment is increased in the presence of IL-6 in Hep3B cells. We also show that the promoter activity of a deletion construct containing only 223 bp of the hAGT gene promoter (that contains only APRE-3) is increased after IL-6 treatment. Our ChIP assay shows that IL-6 treatment recruits STAT-3 to APRE-3 and suggests that this is also an IL6 responsive element. We have previously shown that GR binds to the proximal promoter of the hAGT gene. Since GR physically interacts with STAT-3, we propose that transcription factors GR, STAT-3, and HNF-1α that bind to the nucleotide sequence located between −160 and −280 of the hAGT gene promoter are responsible for IL-6 induced promoter activity of this gene.
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37

Johnson, D., and S. Henikoff. "A moveable 5' splice site in adenine phosphoribosyltransferase genes of Drosophila species." Molecular and Cellular Biology 9, no. 5 (May 1989): 2220–23. http://dx.doi.org/10.1128/mcb.9.5.2220-2223.1989.

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In two distantly related Drosophila species, the use of alternate 5' splice sites to process an intron in pre-mRNA from homologous adenine phosphoribosyltransferase (APRT)-encoding genes led to RNAs encoding nonfunctional peptides in addition to APRT. The production of aberrantly spliced transcripts as a normal feature of gene expression supports a general model of eucaryotic gene evolution through alternative splicing and moveable splice junctions.
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38

Johnson, D., and S. Henikoff. "A moveable 5' splice site in adenine phosphoribosyltransferase genes of Drosophila species." Molecular and Cellular Biology 9, no. 5 (May 1989): 2220–23. http://dx.doi.org/10.1128/mcb.9.5.2220.

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In two distantly related Drosophila species, the use of alternate 5' splice sites to process an intron in pre-mRNA from homologous adenine phosphoribosyltransferase (APRT)-encoding genes led to RNAs encoding nonfunctional peptides in addition to APRT. The production of aberrantly spliced transcripts as a normal feature of gene expression supports a general model of eucaryotic gene evolution through alternative splicing and moveable splice junctions.
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39

Agarwal, Sunita K., David J. Schultz, and Dennis A. Schaff. "APRT SELECTION SYSTEM IN PLANTS." HortScience 27, no. 11 (November 1992): 1160f—1160. http://dx.doi.org/10.21273/hortsci.27.11.1160f.

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Most cells have an active turnover of many of their nucleic acids (particularly some types of RNA) which through degradative processes result in the release of adenine, guanine and hypoxanthine. These free purines are converted to their corresponding nucleotides through salvage pathways. Adenine is converted to its nucleotide form AMP by Adenine phosphoribosyltransferase (APRT) which is one of the enzymes associated with the purine salvage pathway. Since all organisms have a de novo pathway for the formation of AMP, APRT is classified as a `salvage enzyme'. The APRT enzyme, in general, does not show a high degree of specificity for the exact structure of adenine and can also act on cytokinins and adenine derivatives like 2,6-diaminopurine, 2-fluoroadenine and 6-methylpurine. The APRT enzyme can utilize adenine analogues as substrate and convert them into their nucleotide forms which are toxic. Plants that lack APRT activity (APRT-plants) survive in the presense of these analogues. The amount of adenine analogue used for selecting APRT-plants is such that it kills all APRT+ (wild type) plants. APRT+ plants survive when grown in the presense of azaserine and alanosine that block de novo synthesis of AMP. APRT-plants transformed with the wild type cloned gene can be selected from a mixture of transformed and non-transformed plants by selecting in the presense of adenine, azaserine and alanosine. The presense of APRT activity can be confirmed by assaying for the APRT enzyme. APRT activity has been detected in many plant species. The presense of a positive forward and backward selection system can thus allow the use of APRT as a selectable marker in plant gene transfer systems.
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40

Shumaker, J. "APEX disease gene resequencing: mutations in exon 7 of the p53 tumor suppressor gene." Bioorganic & Medicinal Chemistry 9, no. 9 (September 2001): 2269–78. http://dx.doi.org/10.1016/s0968-0896(01)00104-3.

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41

Abe, Sadanobu, Ayako Yasumura, and Teruo Tanaka. "Regulation of Bacillus subtilis aprE Expression by glnA through Inhibition of scoC and σD-Dependent degR Expression." Journal of Bacteriology 191, no. 9 (February 27, 2009): 3050–58. http://dx.doi.org/10.1128/jb.00049-09.

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ABSTRACT Expression of the gene for the extracellular alkaline protease (aprE) of Bacillus subtilis is subject to regulation by many positive and negative regulators. We have found that aprE expression was increased by disruption of the glutamine synthetase gene glnA. The increase in aprE expression was attributed to a decreased in expression of scoC, which encodes a negative regulator of aprE expression. The glnA effect on scoC expression was abolished by further disruption of tnrA, indicating that aprE expression is under global regulation through TnrA. In the scoC background, however, aprE expression was decreased by glnA deletion, and it was shown that the decrease was due to a defect in positive regulation by DegU. Among the genes that affect aprE expression through DegU, the expression of degR, encoding a protein that stabilizes phosphorylated DegU, was inhibited by glnA deletion. It was further shown that the decrease in degR expression by glnA deletion was caused by inhibition of the expression of sigD, encoding the σD factor, which is required for degR expression. In accordance with these findings, the expression levels of aprE-lacZ in glnA scoC degR and scoC degR strains were identical. These results led us to conclude that glnA deletion brings about two effects on aprE expression, i.e., a positive effect through inhibition of scoC expression and a negative effect through inhibition of degR expression, with the former predominating over the latter.
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42

Dush, Michael K., Michael R. Briggs, Melanie E. Royce, Dennis A. Schaff, Sohaib A. Khan, Jay A. Tischfield, and Peter J. Stambrook. "Identification of DNA sequences required for mouse APRT gene expression." Nucleic Acids Research 16, no. 17 (1988): 8509–24. http://dx.doi.org/10.1093/nar/16.17.8509.

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43

Crother, Timothy R., and Milton W. Taylor. "Relationship of the two APRT gene products from saccharomyces cerevisiae." Clinical Biochemistry 30, no. 3 (April 1997): 251. http://dx.doi.org/10.1016/s0009-9120(97)87666-7.

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44

Kawachi, Eiji, Sadanobu Abe, and Teruo Tanaka. "Inhibition of Bacillus subtilis scoC Expression by Multicopy senS." Journal of Bacteriology 187, no. 24 (December 15, 2005): 8526–30. http://dx.doi.org/10.1128/jb.187.24.8526-8530.2005.

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ABSTRACT The Bacillus subtilis aprE gene, which encodes the extracellular alkaline protease, is regulated by many positive and negative transcriptional regulators. SenS is one such positive regulator consisting of 65 amino acids. We found that the senS gene on a multicopy plasmid, pSEN24, caused an increase in aprE expression in strains carrying the upstream region of aprE up to −340 with respect to the transcription initiation site but not in a strain carrying the region up to −299, which is within the binding site of the negative regulator ScoC (Hpr). Epistatic analysis showed that the pSEN24 effect was lost in a scoC-deleted mutant. In accordance with these results, the scoC transcription level as assayed by a scoC-lacZ fusion and Northern analysis was greatly reduced in the cells carrying pSEN24. From these results we conclude that multicopy senS enhances aprE expression by suppressing the transcription of scoC.
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45

Kessler, O., and L. A. Chasin. "Effects of nonsense mutations on nuclear and cytoplasmic adenine phosphoribosyltransferase RNA." Molecular and Cellular Biology 16, no. 8 (August 1996): 4426–35. http://dx.doi.org/10.1128/mcb.16.8.4426.

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We have analyzed Chinese hamster ovary (CHO) cell mutants bearing nonsense codons in four of the five exons of the adenine phosphoribosyltransferase (aprt) gene and have found a pattern of mRNA reduction similar to that seen in systems studied previously: a decrease in steady-state mRNA levels of 5- to 10-fold for mutations in exons 1, 2, and 4 but little effect for mutations in the 3'-most exon (exon 5). Nuclear aprt mRNA levels showed a similar decrease. Nonsense-containing aprt mRNA decayed at the same rate as wild-type mRNA in these cell lines after inhibition of transcription with actinomycin D. Nonsense-containing aprt mRNA is associated with polysomes, ruling out a model in which stable residual mRNA escapes degradation by avoiding translation initiation. A tetracycline-responsive form of the aprt gene was used to compare the stability of nonsense-containing and wild-type aprt mRNAs without globally inhibiting transcription. In contrast to measurements made in the presence of actinomycin D, after inhibition of aprt transcription with tetracycline, a nonsense-mediated destabilization of aprt mRNA was indeed demonstrable. The increased rate of decay of cytoplasmic aprt mRNA seen here could account for the nonsense-mediated reduction in steady-state levels of aprt mRNA. However, the low levels of nonsense-bearing aprt mRNA in the nucleus suggest a sensibility of mRNA to translation or translatability before it exits that compartment. Quantitation of the steady-state levels of transcripts containing introns revealed no accumulation of partially spliced aprt RNA and hence no indication of nonsense-mediated aberrancies in splicing. Our results are consistent with a model in which translation facilitates the export of mRNA through a nuclear pore. However, the mechanism of this intriguing nucleocytoplasmic communication remains to be determined.
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46

Maunsell, Bláithín, Claire Adams, and Fergal O'Gara. "Complex regulation of AprA metalloprotease in Pseudomonas fluorescens M114: evidence for the involvement of iron, the ECF sigma factor, PbrA and pseudobactin M114 siderophore." Microbiology 152, no. 1 (January 1, 2006): 29–42. http://dx.doi.org/10.1099/mic.0.28379-0.

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In the soil bacterium Pseudomonas fluorescens M114, extracellular proteolytic activity and fluorescent siderophore (pseudobactin M114) production were previously shown to be co-ordinately negatively regulated in response to environmental iron levels. An iron-starvation extracytoplasmic function sigma factor, PbrA, required for the transcription of siderophore biosynthetic genes, was also implicated in M114 protease regulation. The current study centred on the characterization and genetic regulation of the gene(s) responsible for protease production in M114. A serralysin-type metalloprotease gene, aprA, was identified and found to encode the major, if not only, extracellular protease produced by this strain. The expression of aprA and its protein product were found to be subject to complex regulation. Transcription analysis confirmed that PbrA was required for full aprA transcription under low iron conditions, while the ferric uptake regulator, Fur, was implicated in aprA repression under high iron conditions. Interestingly, the iron regulation of AprA was dependent on culture conditions, with PbrA-independent AprA-mediated proteolytic activity observed on skim milk agar supplemented with yeast extract, when supplied with iron or purified pseudobactin M114. These effects were not observed on skim milk agar without yeast extract. PbrA-independent aprA expression was also observed from a truncated transcriptional fusion when grown in sucrose asparagine tryptone broth supplied with iron or purified pseudobactin M114. Thus, experimental evidence suggested that iron mediated its effects via transcriptional activation by PbrA under low iron conditions, while an as-yet-unidentified sigma factor(s) may be required for the PbrA-independent aprA expression and AprA proteolytic activity induced by siderophore and iron.
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47

Choi, Julie Y., Wan Liang Li, Richard E. Kouri, Jingwei Yu, Fa Ten Kao, and Gualberto Ruano. "Assignment of the Acute Phase Response Factor (APRF) Gene to 17q21 by Microdissection Clone Sequencing and Fluorescencein SituHybridization of a P1 Clone." Genomics 37, no. 2 (October 1996): 264–65. http://dx.doi.org/10.1006/geno.1996.0556.

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48

Ron, D., A. R. Brasier, K. A. Wright, and J. F. Habener. "The permissive role of glucocorticoids on interleukin-1 stimulation of angiotensinogen gene transcription is mediated by an interaction between inducible enhancers." Molecular and Cellular Biology 10, no. 8 (August 1990): 4389–95. http://dx.doi.org/10.1128/mcb.10.8.4389-4395.1990.

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The acute-phase activation of the rat angiotensinogen (rAT) gene in liver cells is a transcriptional event mediated through an interleukin-1-inducible, NF kappa B-binding, cis-acting element (the acute-phase response element [APRE]). Using a cell culture model for the acute-phase response, we showed that the increase in angiotensionogen mRNA in H35 rat hepatoma cells requires costimulation with glucocorticoids and cytokines. Stably transfected rAT promoter-luciferase reporter genes were also activated by cytokines only in the presence of glucocorticoids. This permissive role of glucocorticoids is dependent on the expression of functional glucocorticoid receptors, because in HepG2 cells naturally deficient in such receptors, rAT gene-luciferase reporter constructs responded to interleukin-1 only when cotransfected with an expression vector for the glucocorticoid receptor. Point mutations in the two rAT gene glucocorticoid response elements located adjacent to the APRE led to loss of interleukin-1 inducibility. Induction of luciferase activity in transfected cells occurred even in the presence of cycloheximide, demonstrating that this synergistic response did not depend on new protein synthesis. Thus, a direct interaction between the interleukin-1-inducible NF kappa B-binding APRE and glucocorticoid response elements, located in cis, underlies the acute-phase activation of the rAT gene.
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49

Ron, D., A. R. Brasier, K. A. Wright, and J. F. Habener. "The permissive role of glucocorticoids on interleukin-1 stimulation of angiotensinogen gene transcription is mediated by an interaction between inducible enhancers." Molecular and Cellular Biology 10, no. 8 (August 1990): 4389–95. http://dx.doi.org/10.1128/mcb.10.8.4389.

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Abstract:
The acute-phase activation of the rat angiotensinogen (rAT) gene in liver cells is a transcriptional event mediated through an interleukin-1-inducible, NF kappa B-binding, cis-acting element (the acute-phase response element [APRE]). Using a cell culture model for the acute-phase response, we showed that the increase in angiotensionogen mRNA in H35 rat hepatoma cells requires costimulation with glucocorticoids and cytokines. Stably transfected rAT promoter-luciferase reporter genes were also activated by cytokines only in the presence of glucocorticoids. This permissive role of glucocorticoids is dependent on the expression of functional glucocorticoid receptors, because in HepG2 cells naturally deficient in such receptors, rAT gene-luciferase reporter constructs responded to interleukin-1 only when cotransfected with an expression vector for the glucocorticoid receptor. Point mutations in the two rAT gene glucocorticoid response elements located adjacent to the APRE led to loss of interleukin-1 inducibility. Induction of luciferase activity in transfected cells occurred even in the presence of cycloheximide, demonstrating that this synergistic response did not depend on new protein synthesis. Thus, a direct interaction between the interleukin-1-inducible NF kappa B-binding APRE and glucocorticoid response elements, located in cis, underlies the acute-phase activation of the rAT gene.
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50

Pires, Jose C. M., Maria C. M. Alvim–Ferraz, Maria C. Pereira, and Fernando G. Martins. "Prediction of PM10 concentrations through multi–gene genetic programming." Atmospheric Pollution Research 1, no. 4 (October 2010): 305–10. http://dx.doi.org/10.5094/apr.2010.038.

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