730 results on '"Phosphate transport"'
Search Results
2. Defense‐related callose synthase PMR4 promotes root hair callose deposition and adaptation to phosphate deficiency in Arabidopsis thaliana.
- Author
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Okada, Kentaro, Yachi, Koei, Nguyen, Tan Anh Nhi, Kanno, Satomi, Yasuda, Shigetaka, Tadai, Haruna, Tateda, Chika, Lee, Tae‐Hong, Nguyen, Uyen, Inoue, Kanako, Tsuchida, Natsuki, Ishihara, Taiga, Miyashima, Shunsuke, Hiruma, Kei, Miwa, Kyoko, Maekawa, Takaki, Notaguchi, Michitaka, and Saijo, Yusuke more...
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GLUCAN synthase , *SALICYLIC acid , *PLANT adaptation , *PLANT nutrition , *PLANT shoots , *ROOT hairs (Botany) - Abstract
SUMMARY: Plants acquire phosphorus (P) primarily as inorganic phosphate (Pi) from the soil. Under Pi deficiency, plants induce an array of physiological and morphological responses, termed phosphate starvation response (PSR), thereby increasing Pi acquisition and use efficiency. However, the mechanisms by which plants adapt to Pi deficiency remain to be elucidated. Here, we report that deposition of a β‐1,3‐glucan polymer called callose is induced in Arabidopsis thaliana root hairs under Pi deficiency, in a manner independent of PSR‐regulating PHR1/PHL1 transcription factors and LPR1/LPR2 ferroxidases. Genetic studies revealed PMR4 (GSL5) callose synthase being required for the callose deposition in Pi‐depleted root hairs. Loss of PMR4 also reduces Pi acquisition in shoots and plant growth under low Pi conditions. The defects are not recovered by simultaneous disruption of SID2, mediating defense‐associated salicylic acid (SA) biosynthesis, excluding SA defense activation from the cause of the observed pmr4 phenotypes. Grafting experiments and characterization of plants expressing PMR4 specifically in root hair cells suggest that a PMR4 pool in the cell type contributes to shoot growth under Pi deficiency. Our findings thus suggest an important role for PMR4 in plant adaptation to Pi deficiency. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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Catalog
3. Dose‐dependent long‐distance movement of microRNA399 duplex regulates phosphate homeostasis in Arabidopsis.
- Author
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Chiang, Chih‐Pin, Li, Jia‐Ling, and Chiou, Tzyy‐Jen
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ARABIDOPSIS , *HOMEOSTASIS , *PHOSPHATES , *ROOTSTOCKS , *LONG-distance running , *PHLOEM , *NON-coding RNA - Abstract
Summary: MicroRNA399 (miR399), a phosphate (Pi) starvation‐induced long‐distance signal, is first produced in shoots and moves to roots to suppress PHO2 encoding a ubiquitin conjugase, leading to enhanced Pi uptake and root‐to‐shoot translocation. However, the molecular mechanism underlying miR399 long‐distance movement remains elusive.Hypocotyl grafting with various Arabidopsis mutants or transgenic lines expressing artificial miR399f was employed. The movement of miR399 across graft junction and the rootstock PHO2 transcript and scion Pi levels were analyzed to elucidate the potential factors involved.Our results showed that miR399f precursors are cell‐autonomous and mature miR399f movement is independent of its biogenesis, sequence context, and length (21 or 22 nucleotides). Expressing viral silencing suppressor P19 in the root stele or blocking unloading in the root phloem pore pericycle (PPP) antagonized its silencing effect, suggesting that the miR399f/miR399f* duplex is a mobile entity unloaded through PPP. Notably, the scion miR399f level positively correlates with its amount translocated to rootstocks, implying dose‐dependent movement.This study uncovers the molecular basis underlying the miR399‐mediated long‐distance silencing in coordinating shoot Pi demand with Pi acquisition and translocation activities in the roots. [ABSTRACT FROM AUTHOR] more...
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- 2023
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4. Distinct and overlapping RGS14 and RGS12 actions regulate NPT2A-mediated phosphate transport.
- Author
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Sneddon, W. Bruce, Ramineni, Suneela, Van Doorn, G. Emme, Hepler, John R., and Friedman, Peter A.
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PROXIMAL kidney tubules , *SCAFFOLD proteins , *HORMONE regulation , *G proteins , *FIBROBLAST growth factors , *G protein coupled receptors - Abstract
Parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF23) control serum phosphate levels by downregulating the renal Na-phosphate transporter NPT2A, thereby decreasing phosphate absorption and augmenting urinary excretion. This mechanism requires NHERF1, a PDZ scaffold protein, and is governed by the regulator of G protein signaling-14 (RGS14), which harbors a carboxy-terminal PDZ ligand that binds NHERF1. RGS14 is part of a triad of structurally related RGS proteins that includes RGS12 and RGS10. Like RGS14, RGS12 contains a class 1 PDZ ligand. However, unlike RGS14, the larger RGS12 contains an upstream PDZ-binding domain. The studies outlined here examined and characterized the binding of RGS12 with NHERF1 and NPT2A and its function on hormone-regulated phosphate transport. Immunoblotting experiments revealed RGS12 C-terminal PDZ ligand binding to NHERF1. Further structural analysis disclosed that NPT2A engaged full-length RGS12 and the upstream fragment containing the PDZ domain. Neither the downstream RGS12 portion nor RGS14 interacted with NPT2A. PTH and FGF23 profoundly inhibited phosphate uptake in opossum kidney proximal tubule cells. Transfection with human RGS14, or human RGS12, abolished hormone-sensitive phosphate transport as reported for human proximal tubule cells. RGS12 inhibitory activity resides in the downstream region and is comparable to RGS14. The carboxy-terminal RGS12(667–1447) splice variant is prominently expressed in the kidney and may contribute to regulating hormone-sensitive phosphate transport. • RGS14 controls PTH and FGF23-sensitive NPT2A-meidated phosphate transport. • RGS12 contains a PDZ ligand like RGS14, and an upstream PDZ-binding domain. • RGS12 binds to NHERF1 and inhibits hormone-sensitive phosphate transport. • RGS inhibitory activity resides in a linker region and not an RGS domain or motif. [ABSTRACT FROM AUTHOR] more...
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- 2024
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5. Evaluation by Means of Electrochemical Impedance Spectroscopy of the Transport of Phosphate Ions through a Heterogeneous Anion-Exchange Membrane at Different pH and Electrolyte Concentration.
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Rotta, Eduardo Henrique, Martí-Calatayud, Manuel César, Pérez-Herranz, Valentín, and Bernardes, Andréa Moura
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IMPEDANCE spectroscopy ,ION-permeable membranes ,ELECTRODIALYSIS ,CHEMICAL reactions ,BOUNDARY layer (Aerodynamics) ,FUNCTIONAL groups - Abstract
Electrodialysis is an innovative technique to reclaim phosphates from municipal wastewater. However, chemical reactions accompany the transport of these ions through ion-exchange membranes. The present study investigates the dependence of these phenomena on the initial pH and concentration of the phosphate-containing solution using a heterogeneous anion-exchange membrane. Linear sweep voltammetry, electrochemical impedance spectroscopy, and chronopotentiometry experiments were conducted for different phosphate-containing systems. For the most diluted solution, two limiting current densities (i
lim ) have been observed for pH 5 and 7.2, while only one ilim for pH 10, and correlated with the appearance of Gerischer arcs in EIS spectra. For pH 7.2, sub-arcs of Gerischer impedance were separated by a loop, indicating the involvement of the membrane functional groups. Increasing the phosphate concentration changed the system's characteristics, reporting a single ilim . In the EIS spectra, the absence of Gerischer elements determined the attenuation of chemical reactions, followed by the development of a diffusion boundary layer, as indicated by the finite-length Warburg arcs. Chronopotentiometry clarified the mass transport mechanism responsible for distorting the diffusion boundary layer thickness at lower concentrations. The obtained results are expected to contribute to the phosphates recovery using electrodialysis in the most varied conditions of pH and concentration available in the environment. [ABSTRACT FROM AUTHOR] more...- Published
- 2023
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6. Combination of magnesium modified biochar and iron oxides down-regulates phosphates transport in porous media.
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Wang, Ning, Pan, Sitong, Li, Shuangchi, Zhang, Miaoyue, and Jiang, Xiaoqian
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OXALIC acid , *IRON oxides , *SAND , *POROSITY , *CITRIC acid , *GOETHITE , *IONIC strength - Abstract
[Display omitted] • Mg-modified biochar exhibited a high P adsorption capacity (∼248 mg g−1). • Goethite was more effective than hematite in reducing P transport in columns. • Coexistence of biochar and goethite increased available retention sites of P. • Citric acid and oxalic acid achieved release of P retained in columns. The practical effects of biochar on soil phosphate (P) transport are significantly affected by P adsorption capacity of biochar itself and its interaction process with iron oxides. Here, the ability of pyrolysis to shape P adsorption capacity of biochar was investigated, while the interaction of biochar and iron oxides on P transport was explored with quartz sand columns and numerical modeling. Adsorption experiments showed that pyrolysis increased P adsorption capacity of Mg-modified biochar (∼248 mg g−1) through enriching surface morphology and pore structures, optimizing composition of functional groups, and forming MgO crystals. It also caused that P adsorption at MgBC-700°C was mainly controlled by surface precipitation, electrostatic attraction and pore interception. Simultaneously, the desorption of P was sensitive to pH changes and with low-stability. Transport experiments showed that iron oxides reduced P transport, shown to be goethite > hematite (P leaching: 69.59 % vs 98.29 %). Further, MgBC-700°C continued to decrease P transport from 75.56 % to 31.50 %, and the effect of goethite was more effective, with ligand reaction playing an important role. This process was influenced by cation types (Ca2+ and K+), ionic strength (1 mM and 50 mM), and pH (5, 7 and 9) through changing available retention sites of columns. Furthermore, since P adsorption mechanisms were different in the presence of MgBC-700°C and goethite than MgBC-700°C only, the changes of pH could no longer cause the release of P, but surprisingly, citric acid and oxalic acid could activate and slowly release the retained P via chelation, ligand exchange, and solubilization, which suggested that MgBC-700°C, as an environmentally-friendly P adsorption and release material, has great potential in reducing P loss and facilitating P utilization. [ABSTRACT FROM AUTHOR] more...
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- 2024
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7. Insights of intracellular/intercellular phosphate transport and signaling in unicellular green algae and multicellular land plants.
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Jia, Xianqing, Wang, Long, Zeng, Houqing, and Yi, Keke
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GREEN algae , *PHOSPHATES , *PLANT growth , *PLANT development , *PHYTOGEOGRAPHY - Abstract
Summary: Phosphorus (P) is an essential element for plant growth and development. Vacuoles play a fundamental role in the storage and remobilization of P in plants, while our understanding of the evolutionary mechanisms of creating and reusing P stores are limited. Besides, we also know very little about the coordination of intercellular P translocation, neither the inorganic phosphate (Pi) signaling nor the Pi transport patterns. Here we summarize recent advances in understanding the core elements involved in cellular and/or subcellular P homeostasis and signaling in unicellular green algae and multicellular land plants. We also propose further work that might help to uncover the high‐resolution intracellular and intercellular landscape of Pi distribution and signaling in plants. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
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8. Potential Networks of Nitrogen-Phosphorus-Potassium Channels and Transporters in Arabidopsis Roots at a Single Cell Resolution
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Dhondup Lhamo and Sheng Luan
- Subjects
root single cell transcriptomics ,expression analysis ,nutrient transporters ,nitrate transport ,phosphate transport ,potassium transport ,Plant culture ,SB1-1110 - Abstract
Nitrogen (N), phosphorus (P), and potassium (K) are three major macronutrients essential for plant life. These nutrients are acquired and transported by several large families of transporters expressed in plant roots. However, it remains largely unknown how these transporters are distributed in different cell-types that work together to transfer the nutrients from the soil to different layers of root cells and eventually reach vasculature for massive flow. Using the single cell transcriptomics data from Arabidopsis roots, we profiled the transcriptional patterns of putative nutrient transporters in different root cell-types. Such analyses identified a number of uncharacterized NPK transporters expressed in the root epidermis to mediate NPK uptake and distribution to the adjacent cells. Some transport genes showed cortex- and endodermis-specific expression to direct the nutrient flow toward the vasculature. For long-distance transport, a variety of transporters were shown to express and potentially function in the xylem and phloem. In the context of subcellular distribution of mineral nutrients, the NPK transporters at subcellular compartments were often found to show ubiquitous expression patterns, which suggests function in house-keeping processes. Overall, these single cell transcriptomic analyses provide working models of nutrient transport from the epidermis across the cortex to the vasculature, which can be further tested experimentally in the future. more...
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- 2021
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9. Potential Networks of Nitrogen-Phosphorus-Potassium Channels and Transporters in Arabidopsis Roots at a Single Cell Resolution.
- Author
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Lhamo, Dhondup and Luan, Sheng
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ARABIDOPSIS ,PLANT roots ,CELL analysis ,BLOOD vessels ,PHLOEM ,MONOAMINE transporters - Abstract
Nitrogen (N), phosphorus (P), and potassium (K) are three major macronutrients essential for plant life. These nutrients are acquired and transported by several large families of transporters expressed in plant roots. However, it remains largely unknown how these transporters are distributed in different cell-types that work together to transfer the nutrients from the soil to different layers of root cells and eventually reach vasculature for massive flow. Using the single cell transcriptomics data from Arabidopsis roots, we profiled the transcriptional patterns of putative nutrient transporters in different root cell-types. Such analyses identified a number of uncharacterized NPK transporters expressed in the root epidermis to mediate NPK uptake and distribution to the adjacent cells. Some transport genes showed cortex- and endodermis-specific expression to direct the nutrient flow toward the vasculature. For long-distance transport, a variety of transporters were shown to express and potentially function in the xylem and phloem. In the context of subcellular distribution of mineral nutrients, the NPK transporters at subcellular compartments were often found to show ubiquitous expression patterns, which suggests function in house-keeping processes. Overall, these single cell transcriptomic analyses provide working models of nutrient transport from the epidermis across the cortex to the vasculature, which can be further tested experimentally in the future. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
- Full Text
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10. Phosphorus and Malignancies
- Author
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Beck, George R., Jr., Bendich, Adrianne, Series editor, Bales, Connie W., Series editor, Gutiérrez, Orlando M., editor, Kalantar-Zadeh, Kamyar, editor, and Mehrotra, Rajnish, editor
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- 2017
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11. PHOSPHATE TRANSPORT IN EPITHELIAL AND NONEPITHELIAL TISSUE.
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Hernando, Nati, Gagnon, Kenneth, and Lederer, Eleanor
- Abstract
Phosphate is an essential nutrient for life and is a critical component of bone formation, a major signaling molecule, and structural component of cell walls. Phosphate is also a component of high-energy compounds (i.e., AMP, ADP, and ATP) and essential for nucleic acid helical structure (i.e., RNA and DNA). Phosphate plays a central role in the process of mineralization, normal serum levels being associated with appropriate bone mineralization, while high and low serum levels are associated with soft tissue calcification. The serum concentration of phosphate and the total body content of phosphate are highly regulated, a process that is accomplished by the coordinated effort of two families of sodium-dependent transporter proteins. The three isoforms of the SLC34 family (SLC34A1--A3) show very restricted tissue expression and regulate intestinal absorption and renal excretion of phosphate. SLC34A2 also regulates the phosphate concentration in multiple lumen fluids including milk, saliva, pancreatic fluid, and surfactant. Both isoforms of the SLC20 family exhibit ubiquitous expression (with some variation as to which one or both are expressed), are regulated by ambient phosphate, and likely serve the phosphate needs of the individual cell. These proteins exhibit similarities to phosphate transporters in nonmammalian organisms. The proteins are nonredundant as mutations in each yield unique clinical presentations. Further research is essential to understand the function, regulation, and coordination of the various phosphate transporters, both the ones described in this review and the phosphate transporters involved in intracellular transport. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
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12. Several phosphate transport processes are present in vascular smooth muscle cells.
- Author
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Hortells, Luis, Guillén, Natalia, Sosa, Cecilia, and Sorribas, Víctor
- Abstract
We have studied inorganic phosphate (Pi) handling in rat aortic vascular smooth muscle cells (VSMC) using 32P-radiotracer assays. Our results have revealed a complex set of mechanisms consisting of 1) well-known PiT1/PiT2-mediated sodium-dependent Pi transport; 2) Slc20-unrelated sodium-dependent Pi transport that is sensitive to the stilbene derivatives 4,4=-diisothiocyanatostilbene-2,2=-disulphonic acid (DIDS) and 4-acetamido-4-isothiocyanostilbene-2,2-disulfonate (SITS); 3) a sodium-independent Pi uptake system that is competitively inhibited by sulfate, bicarbonate, and arsenate and is weakly inhibited by DIDS, SITS, and phosphonoformate; and 4) an exit pathway from the cell that is partially chloride dependent and unrelated to the known anion-exchangers expressed in VSMC. The inhibitions of sodiumindependent Pi transport by sulfate and of sodium-dependent transport by SITS were studied in greater detail. The maximal inhibition by sulfate was similar to that of Pi itself, with a very high inhibition constant (212 mM). SITS only partially inhibited sodium-dependent Pi transport, but the Ki was very low (14 M). Nevertheless, SITS and DIDS did not inhibit Pi transport in Xenopus laevis oocytes expressing PiT1 or PiT2. Both the sodium-dependent and sodium-independent transport systems were highly dependent on VSMC confluence and on the differentiation state, but they were not modified by incubating VSMC for 7 days with 2 mM Pi under nonprecipitating conditions. This work not only shows that the Pi handling by cells is highly complex but also that the transport systems are shared with other ions such as bicarbonate or sulfate. NEW & NOTEWORTHY In addition to the inorganic phosphate (Pi) transporters PiT1 and PiT2, rat vascular smooth muscle cells show a sodium-dependent Pi transport system that is inhibited by DIDS and SITS. A sodium-independent Pi uptake system of high affinity is also expressed, which is inhibited by sulfate, bicarbonate, and arsenate. The exit of excess Pi is through an exchange with extracellular chloride. Whereas the metabolic effects of the inhibitors, if any, cannot be discarded, kinetic analysis during initial velocity suggests competitive inhibition. [ABSTRACT FROM AUTHOR] more...
- Published
- 2020
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13. Barley phosphate transporter 1;6 shows broad inorganic anion transport activity when expressed in Xenopus laevis oocytes
- Author
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Preuss, Christian P, Huang, Chun Y, Gilliham, Matthew, and Tyerman, Stephen D
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Nutrient Acquisition, Homeostasis and Sink/Source Relations ,Hordeum vulgare ,Xenopus laevis oocytes ,HvPht1 ,6 ,pH ,two electrode voltage clamp ,tails analysis ,hyperpolarisation activated transport ,phosphate transport ,nitrate transport ,sulphate transport ,low affinity transport - Abstract
Remobilisation of phosphate (Pi) within a plant is critical for sustaining its growth under external Pi fluctuation and for seed production. The barley transporter, HvPht1;6 has been implicated in Pi remobilisation. However, functional characterisation of HvPht1;6 and other known plant Pi transporters has been limited owing to the lack of a suitable expression system. In this report, we expressed HvPht1;6 in Xenopus laevis oocytes allowing the first detailed characterisation of a plant phosphate transporter. HvPht1;6 increased efflux of Pi near oocyte resting membrane potentials, dependent on external Pi concentration. Inward currents activated by negative membrane potentials were consistent with nH+:HPO42- (n>2) co-transport, and were dependant on Pi concentration gradient and pH. The large inward current (Pi influx) at -150 mV was also observed for other oxyanions including SO42- and NO3-. Inward and outward currents showed linear dependence on the concentration of external HPO42- and membrane potential, suggesting that HvPht1;6 may, in hyperperpolarised phloem cells, load Pi from the apoplast; and in depolarised cells, such as senescing mesophyll cells, unload Pi to the apoplast. The electrophysiological properties of HvPht1;6 are consistent with its suggested role in the remobilisation of Pi in barley plants. Our results demonstrate that using modified bath solution, X. laevis oocytes can be used for studies of electrophysiological properties of plant proton-coupled Pi transporters. more...
- Published
- 2009
14. Renal Tubular Development
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Baum, Michel, Avner, Ellis D., editor, Harmon, William E., editor, Niaudet, Patrick, editor, Yoshikawa, Norishige, editor, Emma, Francesco, editor, and Goldstein, Stuart L., editor
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- 2016
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15. The PolS-PolR Two-Component System Regulates Genes Involved in Poly-P Metabolism and Phosphate Transport in Microlunatus phosphovorus
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Chuanqing Zhong, Peipei Zhang, Cheng Liu, Meng Liu, Wenbing Chen, Jiafang Fu, Xiaoyu Qi, and Guangxiang Cao
- Subjects
polyphosphate metabolism ,two-component system ,gene regulation ,Microlunatus phosphovorus ,phosphate transport ,Microbiology ,QR1-502 - Abstract
Microlunatus phosphovorus NM-1 is a polyphosphate (poly-P)-accumulating bacterium that accumulates poly-P under aerobic conditions and degrades poly-P under anaerobic conditions. In this study, the two-component system (TCS) PolS-PolR was identified in NM-1, and the response regulator PolR was found to directly bind to the promoters of genes related to phosphate transport (MLP_RS00235, MLP_RS23035, and MLP_RS24590); poly-P catabolism (MLP_RS12905) and poly-P synthesis (MLP_RS23025). RT-qPCR assays showed that ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035), and pit (MLP_RS24590) were down-regulated during the aerobic-anaerobic shift. The sequence GTTCACnnnnnGTTCaC was identified as a recognition sequence for PolR by MEME analysis and DNase I footprinting. EMSAs and ChIP-qPCR assays indicated that PolR binds to the promoters of pit (MLP_RS00235), ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035) and pit (MLP_RS24590), and ChIP-qPCR further suggested that the binding affinity of PolR was lower under anaerobic conditions than under aerobic conditions in vivo. These findings indicate that the PolS-PolR TCS in M. phosphovorus may be involved in the regulation of poly-P metabolism in response to levels of dissolved oxygen in the environment, and our results provide insights into new approaches for understanding the mechanisms of phosphorus accumulation and release. more...
- Published
- 2019
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16. The molecular sociology of NHERF1 PDZ proteins controlling renal hormone-regulated phosphate transport.
- Author
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Friedman PA and Mamonova T
- Subjects
- Ion Transport, Biological Transport, Phosphates metabolism, Phosphoproteins metabolism, Sodium-Hydrogen Exchangers chemistry, Sodium-Hydrogen Exchangers metabolism, Parathyroid Hormone metabolism
- Abstract
Parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF23) control extracellular phosphate levels by regulating renal NPT2A-mediated phosphate transport by a process requiring the PDZ scaffold protein NHERF1. NHERF1 possesses two PDZ domains, PDZ1 and PDZ2, with identical core-binding GYGF motifs explicitly recognizing distinct binding partners that play different and specific roles in hormone-regulated phosphate transport. The interaction of PDZ1 and the carboxy-terminal PDZ-binding motif of NPT2A (C-TRL) is required for basal phosphate transport. PDZ2 is a regulatory domain that scaffolds multiple biological targets, including kinases and phosphatases involved in FGF23 and PTH signaling. FGF23 and PTH trigger disassembly of the NHERF1-NPT2A complex through reversible hormone-stimulated phosphorylation with ensuing NPT2A sequestration, down-regulation, and cessation of phosphate absorption. In the absence of NHERF1-NPT2A interaction, inhibition of FGF23 or PTH signaling results in disordered phosphate homeostasis and phosphate wasting. Additional studies are crucial to elucidate how NHERF1 spatiotemporally coordinates cellular partners to regulate extracellular phosphate levels., (© 2024 The Author(s).) more...
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- 2024
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17. The PolS-PolR Two-Component System Regulates Genes Involved in Poly-P Metabolism and Phosphate Transport in Microlunatus phosphovorus.
- Author
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Zhong, Chuanqing, Zhang, Peipei, Liu, Cheng, Liu, Meng, Chen, Wenbing, Fu, Jiafang, Qi, Xiaoyu, and Cao, Guangxiang
- Subjects
PHOSPHATE metabolism ,METABOLIC regulation ,GENES ,GENETIC regulation ,METABOLISM - Abstract
Microlunatus phosphovorus NM-1 is a polyphosphate (poly-P)-accumulating bacterium that accumulates poly-P under aerobic conditions and degrades poly-P under anaerobic conditions. In this study, the two-component system (TCS) PolS-PolR was identified in NM-1, and the response regulator PolR was found to directly bind to the promoters of genes related to phosphate transport (MLP_RS00235, MLP_RS23035, and MLP_RS24590); poly-P catabolism (MLP_RS12905) and poly-P synthesis (MLP_RS23025). RT-qPCR assays showed that ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035), and pit (MLP_RS24590) were down-regulated during the aerobic-anaerobic shift. The sequence GTTCACnnnnnGTTCaC was identified as a recognition sequence for PolR by MEME analysis and DNase I footprinting. EMSAs and ChIP-qPCR assays indicated that PolR binds to the promoters of pit (MLP_RS00235), ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035) and pit (MLP_RS24590), and ChIP-qPCR further suggested that the binding affinity of PolR was lower under anaerobic conditions than under aerobic conditions in vivo. These findings indicate that the PolS-PolR TCS in M. phosphovorus may be involved in the regulation of poly-P metabolism in response to levels of dissolved oxygen in the environment, and our results provide insights into new approaches for understanding the mechanisms of phosphorus accumulation and release. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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- View/download PDF
18. Molecular Mechanisms of Phosphorus Metabolism and Transport during Leaf Senescence
- Author
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Kyla A. Stigter and William C. Plaxton
- Subjects
leaf senescence ,nutrient remobilization ,phosphorus-use efficiency ,phosphorus metabolism ,phosphate transport ,phosphodiesterase ,purple acid phosphatase ,(ribo)nuclease ,Botany ,QK1-989 - Abstract
Leaf senescence, being the final developmental stage of the leaf, signifies the transition from a mature, photosynthetically active organ to the attenuation of said function and eventual death of the leaf. During senescence, essential nutrients sequestered in the leaf, such as phosphorus (P), are mobilized and transported to sink tissues, particularly expanding leaves and developing seeds. Phosphorus recycling is crucial, as it helps to ensure that previously acquired P is not lost to the environment, particularly under the naturally occurring condition where most unfertilized soils contain low levels of soluble orthophosphate (Pi), the only form of P that roots can directly assimilate from the soil. Piecing together the molecular mechanisms that underpin the highly variable efficiencies of P remobilization from senescing leaves by different plant species may be critical for devising effective strategies for improving overall crop P-use efficiency. Maximizing Pi remobilization from senescing leaves using selective breeding and/or biotechnological strategies will help to generate P-efficient crops that would minimize the use of unsustainable and polluting Pi-containing fertilizers in agriculture. This review focuses on the molecular mechanisms whereby P is remobilized from senescing leaves and transported to sink tissues, which encompasses the action of hormones, transcription factors, Pi-scavenging enzymes, and Pi transporters. more...
- Published
- 2015
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19. Epithelial-like transport of mineral distinguishes bone formation from other connective tissues.
- Author
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Blair HC, Larrouture QC, Tourkova IL, Nelson DJ, Dobrowolski SF, and Schlesinger PH
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- Bone and Bones metabolism, Collagen metabolism, Osteoblasts metabolism, Durapatite, Osteogenesis, Calcification, Physiologic physiology
- Abstract
We review unique properties of bone formation including current understanding of mechanisms of bone mineral transport. We focus on formation only; mechanism of bone degradation is a separate topic not considered. Bone matrix is compared to other connective tissues composed mainly of the same proteins, but without the specialized mechanism for continuous transport and deposition of mineral. Indeed other connective tissues add mechanisms to prevent mineral formation. We start with the epithelial-like surfaces that mediate transport of phosphate to be incorporated into hydroxyapatite in bone, or in its ancestral tissue, the tooth. These include several phosphate producing or phosphate transport-related proteins with special expression in large quantities in bone, particularly in the bone-surface osteoblasts. In all connective tissues including bone, the proteins that constitute the protein matrix are mainly type I collagen and γ-carboxylate-containing small proteins in similar molar quantities to collagen. Specialized proteins that regulate connective tissue structure and formation are surprisingly similar in mineralized and non-mineralized tissues. While serum calcium and phosphate are adequate to precipitate mineral, specialized mechanisms normally prevent mineral formation except in bone, where continuous transport and deposition of mineral occurs., (© 2023 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals LLC.) more...
- Published
- 2023
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20. Phosphate homeostasis disorders.
- Author
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Christov, Marta and Jüppner, Harald
- Abstract
Our understanding of the regulation of phosphate balance has benefited tremendously from the molecular identification and characterization of genetic defects leading to a number of rare inherited or acquired disorders affecting phosphate homeostasis. The identification of the key phosphate-regulating hormone, fibroblast growth factor 23 (FGF23), as well as other molecules that control its production, such as the glycosyltransferase GALNT3, the endopeptidase PHEX, and the matrix protein DMP1, and molecules that function as downstream effectors of FGF23 such as the longevity factor Klotho and the phosphate transporters NPT2a and NPT2c, has permitted us to understand the complex interplay that exists between the kidneys, bone, parathyroid, and gut. Such insights from genetic disorders have allowed not only the design of potent targeted treatment of FGF23-dependent hypophosphatemic conditions, but also provide clinically relevant observations related to the dysregulation of mineral ion homeostasis in health and disease. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
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21. AP2 transcription factor CBX1 with a specific function in symbiotic exchange of nutrients in mycorrhizal Lotus japonicus.
- Author
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Li Xue, Lompong Klinnawee, Saridis, Georgios, Gigolashvili, Tamara, Bucher, Marcel, Vijayakumar, Vinod, Yue Zhou, Turck, Franziska, Brands, Mathias, and Dörmann, Peter
- Subjects
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ACTIVATOR protein-2 transcription factors , *PLANT nutrients , *MYCORRHIZAL plants , *LOTUS japonicus , *PHOSPHATE transport proteins , *FATTY acid synthesis - Abstract
The arbuscular mycorrhizal (AM) symbiosis, a widespread mutualistic association between land plants and fungi, depends on reciprocal exchange of phosphorus driven by proton-coupled phosphate uptake into host plants and carbon supplied to AM fungi by host-dependent sugar and lipid biosynthesis. The molecular mechanisms and cis-regulatory modules underlying the control of phosphate uptake and de novo fatty acid synthesis in AM symbiosis are poorly understood. Here, we show that the AP2 family transcription factor CTTC MOTIF-BINDING TRANSCRIPTION FACTOR1 (CBX1), a WRINKLED1 (WRI1) homolog, directly binds the evolutionary conserved CTTC motif that is enriched in mycorrhiza-regulated genes and activates Lotus japonicus phosphate transporter 4 (LjPT4) in vivo and in vitro. Moreover, the mycorrhiza-inducible gene encoding H+-ATPase (LjHA1), implicated in energizing nutrient uptake at the symbiotic interface across the periarbuscular membrane, is coregulated with LjPT4 by CBX1. Accordingly, CBX1-defective mutants show reduced mycorrhizal colonization. Furthermore, genome-wide-binding profiles, DNA-binding studies, and heterologous expression reveal additional binding of CBX1 to AW box, the consensus DNA-binding motif for WRI1, that is enriched in promoters of glycolysis and fatty acid biosynthesis genes. We show that CBX1 activates expression of lipid metabolic genes including glycerol-3-phosphate acyltransferase RAM2 implicated in acylglycerol biosynthesis. Our finding defines the role of CBX1 as a regulator of host genes involved in phosphate uptake and lipid synthesis through binding to the CTTC/AW molecular module, and supports a model underlying bidirectional exchange of phosphorus and carbon, a fundamental trait in the mutualistic AM symbiosis. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
- Full Text
- View/download PDF
22. Renal Tubular Development
- Author
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Baum, Michel, Avner, Ellis, editor, Harmon, William, editor, Niaudet, Patrick, editor, and Yoshikawa, Norishige, editor
- Published
- 2009
- Full Text
- View/download PDF
23. Insights of intracellular/intercellular phosphate transport and signaling in unicellular green algae and multicellular land plants
- Author
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Xianqing Jia, Houqing Zeng, Keke Yi, and Long Wang
- Subjects
Plant growth ,Physiology ,Biological Transport ,Plant Science ,Vacuole ,Biology ,biology.organism_classification ,Phosphates ,Cell biology ,Multicellular organism ,Inorganic phosphate ,Chlorophyta ,Vacuoles ,Embryophyta ,Green algae ,Phosphate transport ,Intracellular - Abstract
Phosphorus (P) is an essential element for plant growth and development. Vacuoles play a fundamental role in the storage and remobilization of P in plants, while our understanding of the evolutionary mechanisms of creating and reusing P stores are limited. Besides, we also know very little about the coordination of intercellular P translocation, neither the inorganic phosphate (Pi) signaling nor the Pi transport patterns. Here we summarize recent advances in understanding the core elements involved in cellular and/or subcellular P homeostasis and signaling in unicellular green algae and multicellular land plants. We also propose further work that might help to uncover the high-resolution intracellular and intercellular landscape of Pi distribution and signaling in plants. more...
- Published
- 2021
- Full Text
- View/download PDF
24. Intracellular phosphate sensing and regulation of phosphate transport systems in plants
- Author
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Hui-Fen Kuo, Tzyy-Jen Chiou, and Zhengrui Wang
- Subjects
Ion Transport ,AcademicSubjects/SCI01270 ,AcademicSubjects/SCI01280 ,Physiology ,Chemistry ,AcademicSubjects/SCI02288 ,AcademicSubjects/SCI02287 ,AcademicSubjects/SCI02286 ,Plant Science ,Cell Communication ,Phosphate ,Update ,Phosphates ,Focus Issue on Transport and Signaling ,chemistry.chemical_compound ,Gene Expression Regulation, Plant ,Genetics ,Biophysics ,Signaling and Response ,Phosphate transport ,Intracellular ,Plant Physiological Phenomena ,Signal Transduction - Abstract
Recent research on the regulation of cellular phosphate (Pi) homeostasis in eukaryotes has collectively made substantial advances in elucidating inositol pyrophosphates (PP-InsP) as Pi signaling molecules that are perceived by the SPX (Syg1, Pho81, and Xpr1) domains residing in multiple proteins involved in Pi transport and signaling. The PP-InsP-SPX signaling module is evolutionarily conserved across eukaryotes and has been elaborately adopted in plant Pi transport and signaling systems. In this review, we have integrated these advances with prior established knowledge of Pi and PP-InsP metabolism, intracellular Pi sensing, and transcriptional responses according to the dynamics of cellular Pi status in plants. Anticipated challenges and pending questions as well as prospects are also discussed., This review article summarizes recent advances in the dynamics of intracellular phosphate metabolism and discusses how it transmits signals to coordinate the cellular phosphate transport systems for cellular Pi homeostasis control. more...
- Published
- 2021
25. Predicting Species-Resolved Macronutrient Acquisition during Succession in a Model Phototrophic Biofilm Using an Integrated ‘Omics Approach
- Author
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Stephen R. Lindemann, Jennifer M. Mobberley, Jessica K. Cole, L. M. Markillie, Ronald C. Taylor, Eric Huang, William B. Chrisler, H. S. Wiley, Mary S. Lipton, William C. Nelson, James K. Fredrickson, and Margaret F. Romine more...
- Subjects
carbon fixation ,nitrate reduction ,phosphate transport ,sulfate reduction ,metagenomics ,metatranscriptomics ,Microbiology ,QR1-502 - Abstract
The principles governing acquisition and interspecies exchange of nutrients in microbial communities and how those exchanges impact community productivity are poorly understood. Here, we examine energy and macronutrient acquisition in unicyanobacterial consortia for which species-resolved genome information exists for all members, allowing us to use multi-omic approaches to predict species’ abilities to acquire resources and examine expression of resource-acquisition genes during succession. Metabolic reconstruction indicated that a majority of heterotrophic community members lacked the genes required to directly acquire the inorganic nutrients provided in culture medium, suggesting high metabolic interdependency. The sole primary producer in consortium UCC-O, cyanobacterium Phormidium sp. OSCR, displayed declining expression of energy harvest, carbon fixation, and nitrate and sulfate reduction proteins but sharply increasing phosphate transporter expression over 28 days. Most heterotrophic members likewise exhibited signs of phosphorus starvation during succession. Though similar in their responses to phosphorus limitation, heterotrophs displayed species-specific expression of nitrogen acquisition genes. These results suggest niche partitioning around nitrogen sources may structure the community when organisms directly compete for limited phosphate. Such niche complementarity around nitrogen sources may increase community diversity and productivity in phosphate-limited phototrophic communities. more...
- Published
- 2017
- Full Text
- View/download PDF
26. Renal Handling of Phosphate
- Author
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Takeda, E., Morita, K., Taketani, Y., Yamamoto, H., Miyamoto, K., Morii, Hirotoshi, editor, Nishizawa, Yoshiki, editor, and Massry, Shaul G., editor
- Published
- 2002
- Full Text
- View/download PDF
27. Phosphate Transporters Expression in Patients with Primary Familial Brain Calcifications.
- Author
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Pimentel, L.F., Lemos, R.R., and Oliveira, J.R.
- Abstract
Primary familial brain calcification (PFBC), formerly known as Fahr disease, is a rare neurological disorder characterized by extensive calcification deposits in the brain. So far, four genes have been reported with variations associated with PFBC, SLC20A2, PDGFβ, PDGFRβ, and XPR1. Using real-time qPCR, we analyzed the expression of three inorganic phosphate (Pi) transporters ( SLC20A1, SLC20A2, and XPR1) in patients with PFBC. Our results showed a significant reduction (~40%) of SLC20A2 expression in the patients carrying mutation whereas no significant change was observed within the patients without known mutations. No difference was detected in SLC20A1 and XPR1 expression between the groups compared to control. The results suggest that mutations in SLC20A2 gene by itself play an import role by reducing its expression in blood of PFBC patients. At the same time, we could not demonstrate a direct co-regulation between the three Pi transporters at mRNA level, once their expression did not change among the groups. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
28. Predicting Species-Resolved Macronutrient Acquisition during Succession in a Model Phototrophic Biofilm Using an Integrated 'Omics Approach.
- Author
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Lindemann, Stephen R., Mobberley, Jennifer M., Cole, Jessica K., Markillie, L. M., Taylor, Ronald C., Huang, Eric, Chrisler, William B., Wiley, H. S., Lipton, Mary S., Nelson, William C., Fredrickson, James K., and Romine, Margaret F. more...
- Subjects
PHOTOSYNTHETIC bacteria ,BACTERIAL succession ,BIOFILMS - Abstract
The principles governing acquisition and interspecies exchange of nutrients in microbial communities and how those exchanges impact community productivity are poorly understood. Here, we examine energy and macronutrient acquisition in unicyanobacterial consortia for which species-resolved genome information exists for all members, allowing us to use multi-omic approaches to predict species' abilities to acquire resources and examine expression of resource-acquisition genes during succession. Metabolic reconstruction indicated that a majority of heterotrophic community members lacked the genes required to directly acquire the inorganic nutrients provided in culture medium, suggesting high metabolic interdependency. The sole primary producer in consortium UCC-O, cyanobacterium Phormidium sp. OSCR, displayed declining expression of energy harvest, carbon fixation, and nitrate and sulfate reduction proteins but sharply increasing phosphate transporter expression over 28 days. Most heterotrophic members likewise exhibited signs of phosphorus starvation during succession. Though similar in their responses to phosphorus limitation, heterotrophs displayed species-specific expression of nitrogen acquisition genes. These results suggest niche partitioning around nitrogen sources may structure the community when organisms directly compete for limited phosphate. Such niche complementarity around nitrogen sources may increase community diversity and productivity in phosphate-limited phototrophic communities. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
29. Transport and homeostasis of potassium and phosphate: limiting factors for sustainable crop production.
- Author
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Mingda Luan, Yumei Tang, Fugeng Zhao, Wenzhi Lan, Ren-jie Tang, Wang Tian, Congong Hou, and Sheng Luan
- Subjects
- *
POTASSIUM content of plants , *PHOSPHATES , *PLANT nutrients , *FOOD security , *HOMEOSTASIS - Abstract
Potassium (K) and phosphate (Pi) are both macronutrients essential for plant growth and crop production, but the unrenewable resources of phosphorus rock and potash have become limiting factors for food security. One critical measure to help solve this problem is to improve nutrient use efficiency (NUE) in plants by understanding and engineering genetic networks for ion uptake, translocation, and storage. Plants have evolved multiple systems to adapt to various nutrient conditions for growth and production. Within the NUE networks, transport proteins and their regulators are the primary players for maintaining nutrient homeostasis and could be utilized to engineer high NUE traits in crop plants. A large number of publications have detailed K+ and Pi transport proteins in plants over the past three decades. Meanwhile, the discovery and validation of their regulatory mechanisms are fast-track topics for research. Here, we provide an overview of K+ and Pi transport proteins and their regulatory mechanisms, which participate in the uptake, translocation, storage, and recycling of these nutrients in plants. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
30. Down-Regulation of the Na+-Coupled Phosphate Transporter NaPi-IIa by AMP-Activated Protein Kinase
- Author
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Miribane Dërmaku-Sopjani, Ahmad Almilaji, Tatsiana Pakladok, Carlos Munoz, Zohreh Hosseinzadeh, María Blecua, Mentor Sopjani, and Florian Lang
- Subjects
Energy depletion ,Phosphate transport ,Compound C ,Kidney ,Dermatology ,RL1-803 ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Background/Aims: The Na+-coupled phosphate transporter NaPi-IIa is the main carrier accomplishing renal tubular phosphate reabsorption. It is driven by the electrochemical Na+ gradient across the apical cell membrane, which is maintained by Na+ extrusion across the basolateral cell membrane through the Na+/K+ ATPase. The operation of NaPi-IIa thus requires energy in order to avoid cellular Na+ accumulation and K+ loss with eventual decrease of cell membrane potential, Cl- entry and cell swelling. Upon energy depletion, early inhibition of Na+-coupled transport processes may delay cell swelling and thus foster cell survival. Energy depletion is sensed by the AMP-activated protein kinase (AMPK), a serine/threonine kinase stimulating several cellular mechanisms increasing energy production and limiting energy utilization. The present study explored whether AMPK influences the activity of NAPi-IIa. Methods: cRNA encoding NAPi-IIa was injected into Xenopus oocytes with or without additional expression of wild-type AMPK (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1-HA), of inactive AMPKαK45R (AMPKα1K45R+AMPKβ1-Flag+AMPKγ1-HA) or of constitutively active AMPKγR70Q (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1R70Q). NaPi-IIa activity was estimated from phosphate-induced current in dual electrode voltage clamp experiments. Results: In NaPi-IIa-expressing, but not in water-injected Xenopus oocytes, the addition of phosphate (1 mM) to the extracellular bath solution generated a current (Ip), which was significantly decreased by coexpression of wild-type AMPK and of AMPKγR70Q but not of AMPKαK45R. The phosphate-induced current in NaPi-IIa- and AMPK-expressing Xenopus ooocytes was significantly increased by AMPK inhibitor Compound C (20 µM). Kinetic analysis revealed that AMPK significantly decreased the maximal transport rate. Conclusion: The AMP-activated protein kinase AMPK is a powerful regulator of NaPi-IIa and thus of renal tubular phosphate transport. more...
- Published
- 2013
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31. Protective effect of ω-3 polyunsaturated fatty acids (PUFA) on sodium nitrite induced nephrotoxicity and oxidative damage in rat kidney
- Author
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Md. Wasim Khan, Natarajan A. Arivarasu, Shubha Priyamvada, Sara Anees Khan, Sheeba Khan, and Ahad Noor Khan Yusufi
- Subjects
Sodium nitrite ,Fish oil ,Flaxseed oil ,Brush border membrane ,Oxidative stress ,Phosphate transport ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Sodium nitrite (SNT) widely used as a curative agent in meat processing industry possesses cell-transforming mutagenic and cytogenic properties. Dietary omega-3 polyunsaturated fatty acids (ω-3 PUFA) has been shown to reduce the severity of certain types of cancers, cardiovascular and renal diseases. The present study examined whether feeding of fish oil (FO)/flaxseed oil (FXO) has protective effect against SNT-induced toxicity. SNT significantly altered the activities of serum creatinine (Crt), blood urea nitrogen (BUN), metabolic and brush border membrane (BBM) enzymes. SNT caused significant imbalances in the antioxidant system associated with increased lipid peroxidation (LPO). Feeding of FO and FXO with SNT ameliorated the changes in various parameters caused by SNT. Nephrotoxicity parameters lowered and enzyme activities of carbohydrate metabolism, BBM and radioactively labeled inorganic phosphate (32Pi) transport were improved to near control values. The results of the present study suggest that ω-3 PUFA-enriched FO and FXO from sea-foods and plant sources respectively are similarly effective in reducing SNT-induced nephrotoxicity and oxidative damage. more...
- Published
- 2013
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- View/download PDF
32. Renal Phosphate Transport
- Author
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Carsten A. Wagner
- Subjects
Biochemistry ,Chemistry ,Phosphate transport - Published
- 2020
- Full Text
- View/download PDF
33. Several phosphate transport processes are present in vascular smooth muscle cells
- Author
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Natalia Guillén, Luis Hortells, Cecilia Sosa, and Victor Sorribas
- Subjects
0301 basic medicine ,4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid ,Vascular smooth muscle ,Physiology ,Myocytes, Smooth Muscle ,4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid ,Muscle, Smooth, Vascular ,Phosphates ,Xenopus laevis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Inorganic phosphate ,Chlorides ,Physiology (medical) ,Stilbenes ,Pi ,Animals ,Phosphate transport ,Anion exchanger ,Sodium-Phosphate Cotransporter Proteins, Type III ,Sodium ,Biological Transport ,Transporter ,Rats ,Kinetics ,030104 developmental biology ,chemistry ,DIDS ,030220 oncology & carcinogenesis ,Oocytes ,Biophysics ,Cardiology and Cardiovascular Medicine ,Transport system - Abstract
We have studied inorganic phosphate (Pi) handling in rat aortic vascular smooth muscle cells (VSMC) using32P-radiotracer assays. Our results have revealed a complex set of mechanisms consisting of 1) well-known PiT1/PiT2-mediated sodium-dependent Pitransport; 2) Slc20-unrelated sodium-dependent Pitransport that is sensitive to the stilbene derivatives 4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid (DIDS) and 4-acetamido-4-isothiocyanostilbene-2,2-disulfonate (SITS); 3) a sodium-independent Piuptake system that is competitively inhibited by sulfate, bicarbonate, and arsenate and is weakly inhibited by DIDS, SITS, and phosphonoformate; and 4) an exit pathway from the cell that is partially chloride dependent and unrelated to the known anion-exchangers expressed in VSMC. The inhibitions of sodium-independent Pitransport by sulfate and of sodium-dependent transport by SITS were studied in greater detail. The maximal inhibition by sulfate was similar to that of Piitself, with a very high inhibition constant (212 mM). SITS only partially inhibited sodium-dependent Pitransport, but the Kiwas very low (14 µM). Nevertheless, SITS and DIDS did not inhibit Pitransport in Xenopus laevis oocytes expressing PiT1 or PiT2. Both the sodium-dependent and sodium-independent transport systems were highly dependent on VSMC confluence and on the differentiation state, but they were not modified by incubating VSMC for 7 days with 2 mM Piunder nonprecipitating conditions. This work not only shows that the Pihandling by cells is highly complex but also that the transport systems are shared with other ions such as bicarbonate or sulfate.NEW & NOTEWORTHY In addition to the inorganic phosphate (Pi) transporters PiT1 and PiT2, rat vascular smooth muscle cells show a sodium-dependent Pitransport system that is inhibited by DIDS and SITS. A sodium-independent Piuptake system of high affinity is also expressed, which is inhibited by sulfate, bicarbonate, and arsenate. The exit of excess Piis through an exchange with extracellular chloride. Whereas the metabolic effects of the inhibitors, if any, cannot be discarded, kinetic analysis during initial velocity suggests competitive inhibition. more...
- Published
- 2020
- Full Text
- View/download PDF
34. Disorders of Phosphate Metabolism
- Author
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Yanagawa, Norimoto, Nemeh, Moufid, Suki, Wadi N., editor, and Massry, Shaul G., editor
- Published
- 1997
- Full Text
- View/download PDF
35. Enterococcus faecalis OG1RF Evolution at Low pH Selects Fusidate-Sensitive Mutants in Elongation Factor G and at High pH Selects Defects in Phosphate Transport.
- Author
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Fitzgerald BA, Wadud A, Slimak Z, and Slonczewski JL
- Subjects
- Humans, Anti-Bacterial Agents pharmacology, Enterococcus metabolism, Biofilms, ATP-Binding Cassette Transporters metabolism, Phosphates metabolism, Enterococcus faecalis, Peptide Elongation Factor G metabolism, Peptide Elongation Factor G pharmacology
- Abstract
Enterococcus bacteria inhabit human and soil environments that show a wide range of pH values. Strains include commensals as well as antibiotic-resistant pathogens. We investigated the adaptation to pH stress in E. faecalis OG1RF by conducting experimental evolution under acidic (pH 4.8), neutral pH (pH 7.0), and basic (pH 9.0) conditions. A serial planktonic culture was performed for 500 generations and in a high-pH biofilm culture for 4 serial bead transfers. Nearly all of the mutations led to nonsynonomous codons, indicating adaptive selection. All of the acid-adapted clones from the planktonic culture showed a mutation in fusA (encoding elongation factor G). The acid-adapted fusA mutants had a trade-off of decreased resistance to fusidic acid (fusidate). All of the base-adapted clones from the planktonic cultures as well as some from the biofilm-adapted cultures showed mutations that affected the Pst phosphate ABC transporter ( pstA , pstB , pstB2 , pstC ) and pyrR (pyrimidine biosynthesis regulator/uracil phosphoribosyltransferase). The biofilm cultures produced small-size colonies on brain heart infusion agar. These variants each contained a single mutation in pstB2 , pstC , or pyrR . The pst and pyrR mutants outgrew the ancestral strain at pH 9.2, with a trade-off of lower growth at pH 4.8. Additional genes that had a mutation in multiple clones that evolved at high pH (but not at low pH) include opp1BCDF (oligopeptide ABC transporter), ccpA (catabolite control protein A), and ftsZ (septation protein). Overall, the experimental evolution of E. faecalis showed a strong pH dependence, favoring the fusidate-sensitive elongation factor G modification at low pH and the loss of phosphate transport genes at high pH. IMPORTANCE E. faecalis bacteria are found in dental biofilms, where they experience low pH as a result of fermentative metabolism. Thus, the effect of pH on antibiotic resistance has clinical importance. The loss of fusidate resistance is notable for OG1RF strains in which fusidate resistance is assumed to be a stable genetic marker. In endodontal infections, enterococci can resist calcium hydroxide therapy that generates extremely high pH values. In other environments, such as the soil and plant rhizosphere, enterococci experience acidification that is associated with climate change. Thus, the pH modulation of natural selection in enterococci is important for human health as well as for understanding soil environments., Competing Interests: The authors declare no conflict of interest. more...
- Published
- 2023
- Full Text
- View/download PDF
36. Phosphate Transport in Capillaries of the Blood-Brain Barrier
- Author
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Béliveau, Richard, Dallaire, Lise, Giroux, Sylvie, Drewes, Lester R., editor, and Betz, A. Lorris, editor
- Published
- 1993
- Full Text
- View/download PDF
37. Evaluation by Means of Electrochemical Impedance Spectroscopy of the Transport of Phosphate Ions through a Heterogeneous Anion-Exchange Membrane at Different pH and Electrolyte Concentration
- Author
-
Eduardo Henrique Rotta, Manuel César Martí-Calatayud, Valentín Pérez-Herranz, and Andréa Moura Bernardes
- Subjects
Geography, Planning and Development ,Aquatic Science ,phosphate transport ,ion-exchange membrane ,limiting current density ,dominant mass transport mechanism ,Gerischer sub-arcs ,Biochemistry ,Water Science and Technology - Abstract
Electrodialysis is an innovative technique to reclaim phosphates from municipal wastewater. However, chemical reactions accompany the transport of these ions through ion-exchange membranes. The present study investigates the dependence of these phenomena on the initial pH and concentration of the phosphate-containing solution using a heterogeneous anion-exchange membrane. Linear sweep voltammetry, electrochemical impedance spectroscopy, and chronopotentiometry experiments were conducted for different phosphate-containing systems. For the most diluted solution, two limiting current densities (ilim) have been observed for pH 5 and 7.2, while only one ilim for pH 10, and correlated with the appearance of Gerischer arcs in EIS spectra. For pH 7.2, sub-arcs of Gerischer impedance were separated by a loop, indicating the involvement of the membrane functional groups. Increasing the phosphate concentration changed the system’s characteristics, reporting a single ilim. In the EIS spectra, the absence of Gerischer elements determined the attenuation of chemical reactions, followed by the development of a diffusion boundary layer, as indicated by the finite-length Warburg arcs. Chronopotentiometry clarified the mass transport mechanism responsible for distorting the diffusion boundary layer thickness at lower concentrations. The obtained results are expected to contribute to the phosphates recovery using electrodialysis in the most varied conditions of pH and concentration available in the environment. more...
- Published
- 2022
- Full Text
- View/download PDF
38. Insulin-Like Growth Factor I (IGF-I), Possible Mediator of the Stimulatory Effects of Growth Hormone on Renal Phosphate Transport and 1,25-Dihydroxyvitamin D3 Production
- Author
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Caverzasio, J., Montessuit, C., Bonjour, J.-P., and Hatano, Michinobu, editor
- Published
- 1991
- Full Text
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39. Towards Structural Identification of the Na+/Pi-Cotransport System
- Author
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Murer, Heini, Werner, Andreas, Wuarin, François, Reshkin, Stephan J., Biber, Jürg, and Hatano, Michinobu, editor
- Published
- 1991
- Full Text
- View/download PDF
40. Mutation of SGK3, a novel regulator of renal phosphate transport, causes autosomal dominant hypophosphatemic Rickets
- Author
-
Yufei Shi, Ali S. Alzahrani, Huda A BinEssa, Anwar F Al-Enezi, Futwan Al-Mohanna, Ayşe Nurcan Cebeci, Brian F. Meyer, Roua A l-Rijjal, Etienne Cavalier, and Minjing Zou
- Subjects
Genetics ,Autosomal dominant hypophosphatemic rickets ,Mutation (genetic algorithm) ,Regulator ,medicine ,Biology ,medicine.disease ,Phosphate transport - Published
- 2021
- Full Text
- View/download PDF
41. PHO1 proteins mediate phosphate transport in the legume-rhizobium symbiosis
- Author
-
Lena Maria Müller
- Subjects
biology ,Symbiosis ,Physiology ,Botany ,Genetics ,Rhizobium ,Plant Science ,Fabaceae ,biology.organism_classification ,Legume ,Medicago truncatula ,Phosphate transport - Published
- 2020
- Full Text
- View/download PDF
42. Fibroblast growth factor 23 and phosphate homeostasis
- Author
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Farzana Perwad and Shanthi Balani
- Subjects
Fibroblast growth factor 23 ,Sodium-Hydrogen Exchangers ,030232 urology & nephrology ,Regulator ,030204 cardiovascular system & hematology ,Phosphate homeostasis ,urologic and male genital diseases ,Phosphates ,Receptors, G-Protein-Coupled ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal Medicine ,medicine ,Animals ,Homeostasis ,Humans ,Receptor ,Phosphate transport ,Kidney ,Chemistry ,Phosphoproteins ,Phosphate ,Cell biology ,Fibroblast Growth Factors ,Fibroblast Growth Factor-23 ,stomatognathic diseases ,Kidney Tubules ,medicine.anatomical_structure ,Parathyroid Hormone ,Nephrology ,Receptors, Virus ,Xenotropic and Polytropic Retrovirus Receptor - Abstract
The current review highlights recent advances in the area of renal tubular phosphate transport and its regulation by fibroblast growth factor 23 (FGF23), a potent regulator of phosphate homeostasis.Recent studies demonstrate that FGF23 binds to both membrane and soluble form of α-klotho to activate FGF receptor signaling pathways. Parathyroid hormone and FGF23 equivalently decrease sodium-dependent phosphate cotransport but the effect is not additive, suggesting a shared but not synergistic mechanism of action. Crosstalk occurs downstream of parathyroid hormone-receptor and FGF23-receptor signaling and converge at the level of the scaffolding protein, sodium-hydrogen exchanger regulatory factor-1. A novel mechanism for phosphate efflux through the basolateral membrane of renal proximal tubular epithelia via an atypical G-protein coupled receptor, Xenotropic and polytropic retrovirus receptor 1 (XPR1), was recently identified. Conditional deletion of Xpr1 gene in renal proximal tubules in mice leads to hypophosphatemic rickets and Fanconi syndrome establishing an important role for XPR1 in phosphate homeostasis. A novel anti-FGF23 antibody, burosumab, was recently approved to treat X-linked hypophosphatemia, a human disorder of FGF23 excess.Significant advances in understanding the cellular and molecular aspects of renal tubular phosphate transport and its regulation by FGF23 has led to the discovery of novel therapeutics to treat human disorders of phosphate homeostasis. more...
- Published
- 2019
- Full Text
- View/download PDF
43. Oral peptide specific egg antibody to intestinal sodium-dependent phosphate co-transporter-2b is effective at altering phosphate transport in vitro and in vivo.
- Author
-
Bobeck, Elizabeth A., Hellestad, Erica M., Sand, Jordan M., Piccione, Michelle L., Bishop, Jeff W., Helvig, Christian, Petkovich, Martin, and Cook, Mark E.
- Subjects
- *
IMMUNIZATION , *PHOSPHATE transport proteins , *IMMUNOGLOBULINS , *EGG yolk , *SODIUM compounds , *NICOTINAMIDE , *IMMUNOHISTOCHEMISTRY , *PEPTIDES - Abstract
Hyperimmunized hens are an effective means of generating large quantities of antigen specific egg antibodies that have use as oral supplements. In this study, we attempted to create a peptide specific antibody that produced outcomes similar to those of the human pharmaceutical, sevelamer HCl, used in the treatment of hyperphosphatemia (a sequela of chronic renal disease). Egg antibodies were generated against 8 different human intestinal sodium-dependent phosphate cotransporter 2b (NaPi2b) peptides, and hNaPi2b peptide egg antibodies were screened for their ability to inhibit phosphate transport in human intestinal Caco-2 cell line. Antibody produced against human peptide sequence TSPSLCWT (anti-h16) was specific for its peptide sequence, and significantly reduced phosphate transport in human Caco-2 cells to 25.3 ± 11.5% of control nonspecific antibody, when compared to nicotinamide, a known inhibitor of phosphate transport (P ≤ 0.05). Antibody was then produced against the mouse-specific peptide h16 counterpart (mouse sequence TSPSYCWT, anti-m16) for further analysis in a murine model. When anti-m16 was fed to mice (1% of diet as dried egg yolk powder), egg yolk immunoglobulin (IgY) was detected using immunohistochemical staining in mouse ileum, and egg anti-m16 IgY colocalized with a commercial goat anti-NaPi2b antibody. The effectiveness of anti-m16 egg antibody in reducing serum phosphate, when compared to sevelamer HCl, was determined in a mouse feeding study. Serum phosphate was reduced 18% (P < 0.02) in mice fed anti-m16 (1% as dried egg yolk powder) and 30% (P < 0.0001) in mice fed sevelamer HCl (1% of diet) when compared to mice fed nonspecific egg immunoglobulin. The methods described and the findings reported show that oral egg antibodies are useful and easy to prepare reagents for the study and possible treatment of select diseases. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
- Full Text
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44. Uptake of inorganic phosphate is a limiting factor for Saccharomyces cerevisiae during growth at low temperatures.
- Author
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Vicent, Isabel, Navarro, Alfonso, Mulet, Jose M., Sharma, Sukesh, and Serrano, Ramón
- Subjects
- *
SACCHAROMYCES cerevisiae , *ALCOHOLIC beverages , *PHOSPHATES , *ERGOSTEROL , *BIOSYNTHESIS , *GLUCONEOGENESIS - Abstract
The fermenting ability of Saccharomyces at low temperatures is crucial for the development of alcoholic beverages, but the key factors for the cold tolerance of yeast are not well known. In this report, we present the results of a screening for genes able to confer cold tolerance by overexpression in a laboratory yeast strain auxotrophic for tryptophan. We identified genes of tryptophan permeases (TAT1 and TAT2), suggesting that the first limiting factor in the growth of tryptophan auxotrophic yeast at low temperatures is tryptophan uptake. This fact is of little relevance to industrial strains which are prototrophic for tryptophan. Then, we screened for genes able to confer growth at low temperatures in tryptophan-rich media and found several genes related to phosphate uptake (PHO84, PHO87, PHO90 and GTR1). This suggests that without tryptophan limitation, uptake of inorganic phosphate becomes the limiting factor. We have found that overexpression of the previously uncharacterized ORF YCR015c/CTO1 increases the uptake of inorganic phosphate. Also, genes involved in ergosterol biosynthesis (NSG2) cause improvement of growth at 10°C, dependent on tryptophan uptake, while the gluconeogenesis gene PCK1 and the proline biosynthesis gene PRO2 cause an improvement in growth at 10°C, independent of tryptophan and phosphate uptake. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
- Full Text
- View/download PDF
45. Differentiating phosphate-dependent and phosphate-independent systemic phosphate-starvation response networks in Arabidopsis thaliana through the application of phosphite.
- Author
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Jost, Ricarda, Pharmawati, Made, Lapis-Gaza, Hazel R., Rossig, Claudia, Berkowitz, Oliver, Lambers, Hans, and Finnegan, Patrick M.
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ARABIDOPSIS thaliana , *PHOSPHATES , *PHOSPHITES , *PLANT cellular signal transduction , *BIOACCUMULATION in plants , *PHYSIOLOGY - Abstract
Phosphite is a less oxidized form of phosphorus than phosphate. Phosphite is considered to be taken up by the plant through phosphate transporters. It can mimic phosphate to some extent, but it is not metabolized into organophosphates. Phosphite could therefore interfere with phosphorus signalling networks. Typical physiological and transcriptional responses to low phosphate availability were investigated and the short-term kinetics of their reversion by phosphite, compared with phosphate, were determined in both roots and shoots of Arabidopsis thaliana. Phosphite treatment resulted in a strong growth arrest. It mimicked phosphate in causing a reduction in leaf anthocyanins and in the expression of a subset of the phosphate-starvation-responsive genes. However, the kinetics of the response were slower than for phosphate, which may be due to discrimination against phosphite by phosphate transporters PHT1;8 and PHT1;9 causing delayed shoot accumulation of phosphite. Transcripts encoding PHT1;7, lipid-remodelling enzymes such as SQD2, and phosphocholine- producing NMT3 were highly responsive to phosphite, suggesting their regulation by a direct phosphate-sensing network. Genes encoding components associated with the 'PHO regulon' in plants, such as At4, IPS1, and PHO1;H1, generally responded more slowly to phosphite than to phosphate, except for SPX1 in roots and MIR399d in shoots. Two uncharacterized phosphate-responsive E3 ligase genes, PUB35 and C3HC4, were also highly phosphite responsive. These results show that phosphite is a valuable tool to identify network components directly responsive to phosphate. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
- Full Text
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46. Potential Networks of Nitrogen-Phosphorus-Potassium Channels and Transporters in Arabidopsis Roots at a Single Cell Resolution
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Sheng Luan and Dhondup Lhamo
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0106 biological sciences ,0301 basic medicine ,Context (language use) ,NPK transport networks ,Plant Science ,01 natural sciences ,potassium transport ,SB1-1110 ,Transcriptome ,03 medical and health sciences ,Nutrient ,Arabidopsis ,root single cell transcriptomics ,nitrate transport ,expression analysis ,phosphate transport ,Original Research ,biology ,Epidermis (botany) ,Chemistry ,Plant culture ,Xylem ,biology.organism_classification ,Cell biology ,030104 developmental biology ,Nitrate transport ,nutrient transporters ,Function (biology) ,010606 plant biology & botany - Abstract
Nitrogen (N), phosphorus (P), and potassium (K) are three major macronutrients essential for plant life. These nutrients are acquired and transported by several large families of transporters expressed in plant roots. However, it remains largely unknown how these transporters are distributed in different cell-types that work together to transfer the nutrients from the soil to different layers of root cells and eventually reach vasculature for massive flow. Using the single cell transcriptomics data from Arabidopsis roots, we profiled the transcriptional patterns of putative nutrient transporters in different root cell-types. Such analyses identified a number of uncharacterized NPK transporters expressed in the root epidermis to mediate NPK uptake and distribution to the adjacent cells. Some transport genes showed cortex- and endodermis-specific expression to direct the nutrient flow toward the vasculature. For long-distance transport, a variety of transporters were shown to express and potentially function in the xylem and phloem. In the context of subcellular distribution of mineral nutrients, the NPK transporters at subcellular compartments were often found to show ubiquitous expression patterns, which suggests function in house-keeping processes. Overall, these single cell transcriptomic analyses provide working models of nutrient transport from the epidermis across the cortex to the vasculature, which can be further tested experimentally in the future. more...
- Published
- 2021
47. Mixtures of rare earth elements show antagonistic interactions in Chlamydomonas reinhardtii
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William Zerges, Kevin J. Wilkinson, Lei Cui, Elise Morel, and Université de Montréal. Faculté des arts et des sciences. Département de chimie
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010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Rare earth ,Chlamydomonas reinhardtii ,Fresh Water ,010501 environmental sciences ,Toxicology ,Transcriptomic analysis ,01 natural sciences ,Metal ,Fight-or-flight response ,Mixture ,Microalgae ,Rare earth elements ,Phosphate transport ,0105 earth and related environmental sciences ,biology ,Chemistry ,Endoplasmic reticulum ,RNA ,Biological Transport ,General Medicine ,biology.organism_classification ,Pollution ,Biochemistry ,13. Climate action ,Metals ,visual_art ,visual_art.visual_art_medium ,Protein folding ,Metals, Rare Earth - Abstract
a bstract In order to better understand the environmental risks of the rare earth elements (REEs), it is necessary to determine their fate and biological effects under environmentally relevant conditions (e.g. at low concentrations, REE mixtures). Here, the unicellular freshwater microalga, Chlamydomonas reinhardtii, was exposed for 2 h to one of three soluble REEs (Ce, Tm, Y) salts at 0.5 μM or to an equimolar mixture of these REEs. RNA sequencing revealed common biological effects among the REEs. Known functions of the differentially expressed genes support effects of REEs on protein processing in the endoplasmic reticulum, phosphate transport and the homeostasis of Fe and Ca. The only stress response detected was related to protein misfolding in the endoplasmic reticulum. When the REEs were applied as a mixture, antagonistic effects were overwhelmingly observed with transcriptomic results suggesting that the REEs were initially competing with each other for bio-uptake. Metal biouptake results were consistent with this interpretation. These results suggest that the approach of government agencies to regulate the REEs using biological effects data from single metal exposures may be a largely conservative approach. more...
- Published
- 2021
48. Noncanonical Sequences Involving NHERF1 Interaction with NPT2A Govern Hormone-Regulated Phosphate Transport: Binding Outside the Box
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Tatyana Mamonova and Peter A. Friedman
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0301 basic medicine ,Protein Conformation ,Amino Acid Motifs ,Parathyroid hormone ,Review ,Ligands ,lcsh:Chemistry ,chemistry.chemical_compound ,binding affinity ,Serine ,Phosphorylation ,Receptor ,lcsh:QH301-705.5 ,Spectroscopy ,Chemistry ,Kinase ,General Medicine ,Computer Science Applications ,Cell biology ,Parathyroid Hormone ,Protein Binding ,Sodium-Hydrogen Exchangers ,PDZ domain ,Sodium-Phosphate Cotransporter Proteins, Type IIa ,parathyroid hormone (PTH) ,Catalysis ,Phosphates ,Inorganic Chemistry ,03 medical and health sciences ,Protein Domains ,Humans ,phosphate transport ,Physical and Theoretical Chemistry ,Molecular Biology ,type II sodium-dependent phosphate cotransporter (NPT2A) ,Ion Transport ,030102 biochemistry & molecular biology ,Organic Chemistry ,Phosphate ,G-Protein-Coupled Receptor Kinases ,Phosphoproteins ,Hormones ,PDZ-ligand interaction ,Fibroblast Growth Factor-23 ,030104 developmental biology ,lcsh:Biology (General) ,lcsh:QD1-999 ,Phosphoprotein ,Mutation ,Cotransporter - Abstract
Na+/H+ exchange factor-1 (NHERF1), a multidomain PDZ scaffolding phosphoprotein, is required for the type II sodium-dependent phosphate cotransporter (NPT2A)-mediated renal phosphate absorption. Both PDZ1 and PDZ2 domains are involved in NPT2A-dependent phosphate uptake. Though harboring identical core-binding motifs, PDZ1 and PDZ2 play entirely different roles in hormone-regulated phosphate transport. PDZ1 is required for the interaction with the C-terminal PDZ-binding sequence of NPT2A (-TRL). Remarkably, phosphocycling at Ser290 distant from PDZ1, the penultimate step for both parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF23) regulation, controls the association between NHERF1 and NPT2A. PDZ2 interacts with the C-terminal PDZ-recognition motif (-TRL) of G Protein-coupled Receptor Kinase 6A (GRK6A), and that promotes phosphorylation of Ser290. The compelling biological puzzle is how PDZ1 and PDZ2 with identical GYGF core-binding motifs specifically recognize distinct binding partners. Binding determinants distinct from the canonical PDZ-ligand interactions and located “outside the box” explain PDZ domain specificity. Phosphorylation of NHERF1 by diverse kinases and associated conformational changes in NHERF1 add more complexity to PDZ-binding diversity. more...
- Published
- 2021
49. Na+-independent phosphate transport in Caco2BBE cells.
- Author
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Candeal, Eduardo, Caldas, Yupanqui A., Guillén, Natalia, Levi, Moshe, and Sorribas, Víctor
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PHOSPHATE transport proteins , *EPITHELIAL cells , *CYCLOHEXIMIDE , *DACTINOMYCIN , *SMALL intestine - Abstract
Pi transport in epithelia has both Na+-dependent and Na+-independent components, but so far only Na+-dependent transporters have been characterized in detail and molecularly identified. Consequently, in the present study, we initiated the characterization and analysis of intestinal Na+-independent P¡ transport using an in vitro model, Caco2BBE cells. Only Na+-independent Pi uptake was observed in these cells, and Pi uptake was dramatically increased when cells were incubated in high-Pi DMEM (4 mM) from 1 day to several days. No response to low-Pi medium was observed. The increased Pi transport was mainly caused by Vmax changes, and it was prevented by actinomycin D and cycloheximide. Pi transport in cells grown in 1 mM Pi (basal DMEM) decreased at pH > 7.5, and it was inhibited with proton ionophores. Pi transport in cells incubated with 4 mM Pi increased with alkaline pH, suggesting a preference for divalent phosphate. Pi uptake in cells in 1 mM Pi was completely inhibited only by Pi and partially inhibited by phosphonoformate, oxalate, DIDS, SITS, SO42-, HCO3-, and arsenate. This inhibition pattern suggests that more than one Pi transporter is active in cells maintained with 1 mM Pi. Phosphate transport from cells maintained at 4 mM Pi was only partially inhibited by phosphonoformate, oxalate, and arsenate. Attempts to identify the responsible transporters showed that multifunctional anion exchangers of the Slc26 family as well as members of Slc17, Slc20, and Slc37 and the P¡ exporter xenotropic and polytropic retrovirus receptor 1 are not involved. [ABSTRACT FROM AUTHOR] more...
- Published
- 2014
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50. Multisite NHERF1 phosphorylation controls GRK6A regulation of hormone-sensitive phosphate transport
- Author
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Peter A. Friedman, Kristian Strømgaard, Tatyana Mamonova, Sofie Bach, W. Bruce Sneddon, and Maria Vistrup-Parry
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0301 basic medicine ,Protein Conformation ,Parathyroid hormone ,PDZ Domains ,TBST, Tris-buffered saline plus Tween 20 ,GRK6A, G protein–coupled receptor kinase 6A ,Biochemistry ,GRK6Act-9, -568SEEELPTRL576 ,binding affinity ,OKH, opossum kidney clone H ,Phosphorylation ,PTH, parathyroid hormone ,Receptor ,Alanine ,GRK6Act-22, -553QRLFSRQDCCGNCSEEELPTRL576 ,Chemistry ,Kinase ,FA, fluorescence anisotropy ,simulation ,Cell biology ,pSer162, phosphorylated Ser162 ,Parathyroid Hormone ,CFTR, cystic fibrosis transmembrane conductance regulator ,Protein Binding ,Research Article ,NPT2A, type II sodium-dependent phosphate cotransporter ,Sodium-Hydrogen Exchangers ,PDZ domain ,Molecular Dynamics Simulation ,Sodium-Phosphate Cotransporter Proteins, Type IIa ,parathyroid hormone (PTH) ,Phosphates ,03 medical and health sciences ,C-terminal, carboxy-terminal ,Humans ,phosphate transport ,Molecular Biology ,Ion Transport ,030102 biochemistry & molecular biology ,Biological Transport ,Cell Biology ,NHERF1, Na+/H+-exchanger regulatory factor-1 ,G-Protein-Coupled Receptor Kinases ,Phosphoproteins ,Fibroblast Growth Factors ,PDZ-ligand interaction ,Fibroblast Growth Factor-23 ,030104 developmental biology ,G protein–coupled receptor kinase 6A (GRK6A) ,EBD, ezrin-binding domain ,Phosphoprotein ,OK cells, opossum kidney cells ,Cotransporter - Abstract
The type II sodium-dependent phosphate cotransporter (NPT2A) mediates renal phosphate uptake. The NPT2A is regulated by parathyroid hormone (PTH) and fibroblast growth factor 23, which requires Na+/H+ exchange regulatory factor-1 (NHERF1), a multidomain PDZ-containing phosphoprotein. Phosphocycling controls the association between NHERF1 and the NPT2A. Here, we characterize the critical involvement of G protein–coupled receptor kinase 6A (GRK6A) in mediating PTH-sensitive phosphate transport by targeted phosphorylation coupled with NHERF1 conformational rearrangement, which in turn allows phosphorylation at a secondary site. GRK6A, through its carboxy-terminal PDZ recognition motif, binds NHERF1 PDZ1 with greater affinity than PDZ2. However, the association between NHERF1 PDZ2 and GRK6A is necessary for PTH action. Ser162, a PKCα phosphorylation site in PDZ2, regulates the binding affinity between PDZ2 and GRK6A. Substitution of Ser162 with alanine (S162A) blocks the PTH action but does not disrupt the interaction between NHERF1 and the NPT2A. Replacement of Ser162 with aspartic acid (S162D) abrogates the interaction between NHERF1 and the NPT2A and concurrently PTH action. We used amber codon suppression to generate a phosphorylated Ser162(pSer162)-PDZ2 variant. KD values determined by fluorescence anisotropy indicate that incorporation of pSer162 increased the binding affinity to the carboxy terminus of GRK6A 2-fold compared with WT PDZ2. Molecular dynamics simulations predict formation of an electrostatic network between pSer162 and Asp183 of PDZ2 and Arg at position −1 of the GRK6A PDZ-binding motif. Our results suggest that PDZ2 plays a regulatory role in PTH-sensitive NPT2A-mediated phosphate transport and phosphorylation of Ser162 in PDZ2 modulates the interaction with GRK6A. more...
- Published
- 2020
- Full Text
- View/download PDF
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