K+ influx by Kup in Escherichia coli is accompanied by a decrease in H+ efflux

Zakharyan, E

doi:10.1016/s0378-1097(01)00375-5

Cited by 16 publications

(19 citation statements)

References 13 publications

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“…The Kdp system is a high-affinity K ϩ transport system that is induced in low-K ϩ environments (K ϩ concentration, 5 mM or less) (15,17). The Kup system has an affinity for K ϩ similar to that of the Trk system and is believed to be the major K ϩ transport system under acidic conditions (44,48). Previous studies showed that Salmonella trkA (sapG), which encodes an essential NAD ϩ binding subunit of the Trk system, was necessary for resistance to antimicrobial peptides (37).…”

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confidence: 99%

The Potassium Transporter Trk and External Potassium Modulate Salmonella enterica Protein Secretion and Virulence

Gong

Lai

et al. 2009

Infect Immun

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Potassium (K؉ ) is the most abundant intracellular cation and is essential for many physiological functions of all living organisms; however, its role in the pathogenesis of human pathogens is not well understood. In this study, we characterized the functions of the bacterial Trk K ؉ transport system and external K ؉ in the pathogenesis of Salmonella enterica, a major food-borne bacterial pathogen. Here we report that Trk is important for Salmonella to invade and grow inside epithelial cells. It is also necessary for the full virulence of Salmonella in an animal infection model. Analysis of proteins of Salmonella indicated that Trk is involved in the expression and secretion of effector proteins of the type III secretion system (TTSS) encoded by Salmonella pathogenicity island 1 (SPI1) that were previously shown to be necessary for Salmonella invasion. In addition to the role of the Trk transporter in the pathogenesis of Salmonella, we discovered that external K ؉ modulates the pathogenic properties of Salmonella by increasing the expression and secretion of effector proteins of the SPI1-encoded TTSS and by enhancing epithelial cell invasion. Our studies demonstrated that K ؉ is actively involved in the pathogenesis of Salmonella and indicated that Salmonella may take advantage of the high K ؉ content inside host cells and in the intestinal fluid during diarrhea to become more virulent.

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The Potassium Transporter Trk and External Potassium Modulate Salmonella enterica Protein Secretion and Virulence

Gong

Lai

et al. 2009

Infect Immun

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“…Moreover, there is increasing evidence suggesting that many KT-HAK-KUP transporters are low-affinity transporters (Quintero and Blatt, 1997;Senn et al, 2001), which apparently overlap their K ϩ concentration range of activities with K ϩ channels. This apparent duplication of transporters with similar affinities for K ϩ could be explained if transporters of the Kup-HAK family mediated active K ϩ -H ϩ cotransport (Rodríguez-Navarro, 2000; Zakharyan and Trchounian, 2001), and the other transporters were uniporters allowing only electrochemical equilibrium. This hypothesis would give a good explanation for the extensive existence of Kup-HAK family of transporters in so many different organisms, but needs to be proved.…”

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confidence: 99%

Inventory and Functional Characterization of the HAK Potassium Transporters of Rice

et al. 2002

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Plants take up large amounts of K+ from the soil solution and distribute it to the cells of all organs, where it fulfills important physiological functions. Transport of K+from the soil solution to its final destination is mediated by channels and transporters. To better understand K+ movements in plants, we intended to characterize the function of the large KT-HAK-KUP family of transporters in rice (Oryza sativacv Nipponbare). By searching in databases and cDNA cloning, we have identified 17 genes (OsHAK1–17) encoding transporters of this family and obtained evidence of the existence of other two genes. Phylogenetic analysis of the encoded transporters reveals a great diversity among them, and three distant transporters, OsHAK1, OsHAK7, and OsHAK10, were expressed in yeast (Saccharomyces cerevisiae) and bacterial mutants to determine their functions. The three transporters mediate K+ influxes or effluxes, depending on the conditions of the experiment. A comparative kinetic analysis of HAK-mediated K+ influx in yeast and in roots of K+-starved rice seedlings demonstrated the involvement of HAK transporters in root K+ uptake. We discuss that all HAK transporters may mediate K+ transport, but probably not only in the plasma membrane. Transient expression of the OsHAK10-green fluorescent protein fusion protein in living onion epidermal cells targeted this protein to the tonoplast.

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“…Escherichia coli wild type strain K-12(k) was grown in peptone medium (0.2% peptone, 0.5% NaCl, and 0.2% K 2 HPO 4 , pH 7.5), under anaerobic conditions upon glucose (0.2%) fermentation at 37°C till stationary growth phase (18-20 h) [11,14,15,24,25]. Grown and concentrated cells were transferred into bi-distilled water or into assay buffer (150 mM Tris-phosphate buffer containing 0.4 mM MgSO 4 , 1 mM KCl, and 1 mM NaCl, pH 7.5).…”

Section: Bacteria and Preparation To Experimentsmentioning

confidence: 99%

“…The SigmaPlot software [28] were used for determination of the standard errors (\3%) and the Student's t test calculation with the validity criteria (P) (validity for the difference between the changed values for each average data and the nonirradiated control) [29]. The statistical analysis used was effectively applied elsewhere [10,24,30].…”

Section: Data Processingmentioning

confidence: 99%

Low Intensity Electromagnetic Irradiation with 70.6 and 73 GHz Frequencies Affects Escherichia coli Growth and Changes Water Properties

Torgomyan

Kalantaryan

Trchоunian

2011

Cell Biochem Biophys

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The low intensity electromagnetic irradiation (EMI) of the 70.6 and 73 GHz frequency is resonant for Escherichia coli but not for water. In this study, E. coli irradiation with this EMI during 1 h directly and in bi-distilled water or in the assay buffer with those frequencies resulted with noticeable changes in bacterial growth parameters. Furthermore, after EMI, 2 h rest of bacteria renewed their growth in 1.2-fold, but repeated EMI--had no significant action. Moreover, water absorbance, pH, and electric conductance were changed markedly after such irradiation. The results point out that EMI of the 70.6 and 73 GHz frequency can interact with bacteria affecting growth and in the same time with the surrounding medium (water) as well.

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K+ influx by Kup in Escherichia coli is accompanied by a decrease in H+ efflux

Cited by 16 publications

References 13 publications

The Potassium Transporter Trk and External Potassium Modulate Salmonella enterica Protein Secretion and Virulence

The Potassium Transporter Trk and External Potassium Modulate Salmonella enterica Protein Secretion and Virulence

Inventory and Functional Characterization of the HAK Potassium Transporters of Rice

Low Intensity Electromagnetic Irradiation with 70.6 and 73 GHz Frequencies Affects Escherichia coli Growth and Changes Water Properties

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