RESUMEN

Low phosphate (Pi) availability decreases photosynthesis, with phosphate limitation of photosynthesis occurring particularly during grain filling of cereal crops; however, effective genetic solutions remain to be established. We previously discovered that rice phosphate transporter OsPHO1;2 controls seed (sink) development through Pi reallocation during grain filling. Here, we find that OsPHO1;2 regulates Pi homeostasis and thus photosynthesis in leaves (source). Loss-of-function of OsPHO1;2 decreased Pi levels in leaves, leading to decreased photosynthetic electron transport activity, CO2 assimilation rate, and early occurrence of phosphate-limited photosynthesis. Interestingly, ectopic expression of OsPHO1;2 greatly increased Pi availability, and thereby, increased photosynthetic rate in leaves during grain filling, contributing to increased yield. This was supported by the effect of foliar Pi application. Moreover, analysis of core rice germplasm resources revealed that higher OsPHO1;2 expression was associated with enhanced photosynthesis and yield potential compared to those with lower expression. These findings reveal that phosphate-limitation of photosynthesis can be relieved via a genetic approach, and the OsPHO1;2 gene can be employed to reinforce crop breeding strategies for achieving higher photosynthetic efficiency.

Asunto(s)

Oryza , Fosfatos , Fotosíntesis , Oryza/genética , Oryza/metabolismo , Oryza/crecimiento & desarrollo , Fosfatos/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Plantas Modificadas Genéticamente

RESUMEN

Phosphorus is essential in all cells' structural, metabolic and regulatory functions. For fungal cells that import inorganic phosphate (Pi) up a steep concentration gradient, surface Pi transporters are critical capacitators of growth. Fungi must deploy Pi transporters that enable optimal Pi uptake in pH and Pi concentration ranges prevalent in their environments. Single, triple and quadruple mutants were used to characterize the four Pi transporters we identified for the human fungal pathogen Candida albicans, which must adapt to alkaline conditions during invasion of the host bloodstream and deep organs. A high-affinity Pi transporter, Pho84, was most efficient across the widest pH range while another, Pho89, showed high-affinity characteristics only within one pH unit of neutral. Two low-affinity Pi transporters, Pho87 and Fgr2, were active only in acidic conditions. Only Pho84 among the Pi transporters was clearly required in previously identified Pi-related functions including Target of Rapamycin Complex 1 signaling, oxidative stress resistance and hyphal growth. We used in vitro evolution and whole genome sequencing as an unbiased forward genetic approach to probe adaptation to prolonged Pi scarcity of two quadruple mutant lineages lacking all 4 Pi transporters. Lineage-specific genomic changes corresponded to divergent success of the two lineages in fitness recovery during Pi limitation. Initial, large-scale genomic alterations like aneuploidies and loss of heterozygosity eventually resolved, as populations gained small-scale mutations. Severity of some phenotypes linked to Pi starvation, like cell wall stress hypersensitivity, decreased in parallel to evolving populations' fitness recovery in Pi scarcity, while severity of others like membrane stress responses diverged from Pi scarcity fitness. Among preliminary candidate genes for contributors to fitness recovery, those with links to TORC1 were overrepresented. Since Pi homeostasis differs substantially between fungi and humans, adaptive processes to Pi deprivation may harbor small-molecule targets that impact fungal growth, stress resistance and virulence.

Asunto(s)

Adaptación Fisiológica , Candida albicans , Proteínas Fúngicas , Fosfatos , Fosfatos/metabolismo , Candida albicans/genética , Candida albicans/metabolismo , Adaptación Fisiológica/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Concentración de Iones de Hidrógeno , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Mutación , Regulación Fúngica de la Expresión Génica , Humanos , Transporte Biológico/genética

RESUMEN

Chromium (Cr) soil contamination is a critical global environmental concern, with hexavalent chromium (Cr[VI]) being especially perilous due to its high mobility, bioavailability, and phytotoxicity. This poses a significant threat to the cultivation of crops, particularly rice, where the mechanisms of Cr(VI) absorption remain largely unexplored. This study uncovered a competitive interaction between Cr(VI) and essential nutrients-sulfate and phosphate during the uptake process. Notably, deficiencies in sulfate and phosphate were associated with a marked increase in Cr(VI) accumulation in rice, reaching up to 76.5 % and 77.7 %, respectively. Employing q-PCR, this study identified significant up-regulation of the sulfate transporter gene, OsSultr1;2, and the phosphate transporter gene, OsPht1;1, in response to Cr(VI) stress. Genetic knockout studies have confirmed the crucial role of OsSultr1;2 in Cr(VI) uptake, with its deletion leading to a 36.1 % to 69.6 % decrease in Cr uptake by rice roots. Similarly, the knockout of OsPht1;1 resulted in an 18.1 % to 25.7 % decrease in root Cr accumulation. These findings highlight the key role of the sulfate transporter OsSultr1;2 in Cr(VI) uptake, with phosphate transporters also contributing significantly to the process. These insights are valuable for developing rice varieties with reduced Cr(VI) accumulation, ensuring the safety of rice grain production.

Asunto(s)

Cromo , Oryza , Proteínas de Transporte de Fosfato , Fosfatos , Contaminantes del Suelo , Sulfatos , Oryza/metabolismo , Oryza/genética , Oryza/crecimiento & desarrollo , Cromo/metabolismo , Cromo/toxicidad , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Sulfatos/metabolismo , Fosfatos/metabolismo , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/toxicidad , Proteínas de Transporte de Anión/metabolismo , Proteínas de Transporte de Anión/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Transportadores de Sulfato/metabolismo , Transportadores de Sulfato/genética , Raíces de Plantas/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos

RESUMEN

We have functionally characterized the high-affinity phosphate transporter (PiPT) from the root endophyte fungus Piriformospora indica. PiPT belongs to the major facilitator superfamily (MFS). PiPT protein was purified by affinity chromatography (Ni-NTA) and Size Exclusion Chromatography (SEC). The functionality of solubilized PiPT was determined in detergent-solubilized state by fluorescence quenching and in proteoliposomes. In the fluorescence quenching assay, PiPT exhibited a saturation concentration of approximately 2 µM, at a pH of 4.5. Proteoliposomes of size 121.6 nm radius, showed transportation of radioactive phosphate. Vmax was measured to be 232.2 ± 11 pmol/min/mg protein. We have found Km to be 45.8 ± 6.2 µM suggesting high affinity towards phosphate.

Asunto(s)

Basidiomycota , Proteínas de Transporte de Fosfato , Basidiomycota/metabolismo , Basidiomycota/química , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/química , Proteínas Fúngicas/química , Proteínas Fúngicas/aislamiento & purificación , Proteínas Fúngicas/metabolismo , Endófitos/metabolismo , Endófitos/química , Raíces de Plantas/microbiología , Raíces de Plantas/química , Fosfatos/metabolismo , Fosfatos/química

RESUMEN

BACKGROUND: Phosphorus (P) deficiency, a major nutrient stress, greatly hinders plant growth. Phosphate (Pi) uptake in plant roots relies on PHT1 family transporters. However, melon (Cucumis melo L.) lacks comprehensive identification and characterization of PHT1 genes, particularly their response patterns under diverse stresses. RESULTS: This study identified and analyzed seven putative CmPHT1 genes on chromosomes 3, 4, 5, 6, and 7 using the melon genome. Phylogenetic analysis revealed shared motifs, domain compositions, and evolutionary relationships among genes with close histories. Exon number varied from 1 to 3. Collinearity analysis suggested segmental and tandem duplications as the primary mechanisms for CmPHT1 gene family expansion. CmPHT1;4 and CmPHT1;5 emerged as a tandemly duplicated pair. Analysis of cis-elements in CmPHT1 promoters identified 14 functional categories, including putative PHR1-binding sites (P1BS) in CmPHT1;4, CmPHT1;6, and CmPHT1;7. We identified that three WRKY transcription factors regulated CmPHT1;5 expression by binding to its W-box element. Notably, CmPHT1 promoters harbored cis-elements responsive to hormones and abiotic factors. Different stresses regulated CmPHT1 expression differently, suggesting that the adjusted expression patterns might contribute to plant adaptation. CONCLUSIONS: This study unveils the characteristics, evolutionary diversity, and stress responsiveness of CmPHT1 genes in melon. These findings lay the foundation for in-depth investigations into their functional mechanisms in Cucurbitaceae crops.

Asunto(s)

Cucumis melo , Regulación de la Expresión Génica de las Plantas , Fosfatos , Filogenia , Proteínas de Plantas , Estrés Fisiológico , Cucumis melo/genética , Cucumis melo/metabolismo , Fosfatos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estrés Fisiológico/genética , Genes de Plantas , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Transporte Biológico/genética

RESUMEN

In bacteria, the availability of environmental inorganic phosphate is typically sensed by the conserved PhoR-PhoB two-component signal transduction pathway, which uses the flux through the PstSCAB phosphate transporter as a readout of the extracellular phosphate level to control phosphate-responsive genes. While the sensing of environmental phosphate is well-investigated, the regulatory effects of cytoplasmic phosphate are unclear. Here, we disentangle the physiological and transcriptional responses of Caulobacter crescentus to changes in the environmental and cytoplasmic phosphate levels by uncoupling phosphate uptake from the activity of the PstSCAB system, using an additional, heterologously produced phosphate transporter. This approach reveals a two-pronged response of C. crescentus to phosphate limitation, in which PhoR-PhoB signaling mostly facilitates the utilization of alternative phosphate sources, whereas the cytoplasmic phosphate level controls the morphological and physiological adaptation of cells to growth under global phosphate limitation. These findings open the door to a comprehensive understanding of phosphate signaling in bacteria.

Asunto(s)

Proteínas Bacterianas , Caulobacter crescentus , Citoplasma , Regulación Bacteriana de la Expresión Génica , Fosfatos , Caulobacter crescentus/genética , Caulobacter crescentus/metabolismo , Caulobacter crescentus/crecimiento & desarrollo , Fosfatos/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Citoplasma/metabolismo , Transducción de Señal , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética

RESUMEN

The concentration of inorganic phosphate (Pi) in the chloroplast stroma must be maintained within narrow limits to sustain photosynthesis and to direct the partitioning of fixed carbon. However, it is unknown if these limits or the underlying contributions of different chloroplastic Pi transporters vary throughout the photoperiod or between chloroplasts in different leaf tissues. To address these questions, we applied live Pi imaging to Arabidopsis (Arabidopsis thaliana) wild-type plants and 2 loss-of-function transporter mutants: triose phosphate/phosphate translocator (tpt), phosphate transporter 2;1 (pht2;1), and tpt pht2;1. Our analyses revealed that stromal Pi varies spatially and temporally, and that TPT and PHT2;1 contribute to Pi import with overlapping tissue specificities. Further, the series of progressively diminished steady-state stromal Pi levels in these mutants provided the means to examine the effects of Pi on photosynthetic efficiency without imposing nutritional deprivation. ΦPSII and nonphotochemical quenching (NPQ) correlated with stromal Pi levels. However, the proton efflux activity of the ATP synthase (gH+) and the thylakoid proton motive force (pmf) were unaltered under growth conditions, but were suppressed transiently after a dark to light transition with return to wild-type levels within 2 min. These results argue against a simple substrate-level limitation of ATP synthase by depletion of stromal Pi, favoring more integrated regulatory models, which include rapid acclimation of thylakoid ATP synthase activity to reduced Pi levels.

Asunto(s)

Arabidopsis , Cloroplastos , Fosfatos , Fotosíntesis , Fosfatos/metabolismo , Fosfatos/deficiencia , Arabidopsis/genética , Arabidopsis/fisiología , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Mutación/genética , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Plantas Modificadas Genéticamente , Tilacoides/metabolismo

RESUMEN

Phosphorus nutrition has been known for a long time to influence floral transition in plants, but the underlying mechanism is unclear. Arabidopsis phosphate transporter PHOSPHATE1 (PHO1) plays a critical role in phosphate translocation from roots to shoots, but whether and how it regulates floral transition is unknown. Here, we show that knockout mutation of PHO1 delays flowering under both long- and short-day conditions. The late flowering of pho1 mutants can be partially rescued by Pi supplementation in rosettes or shoot apices. Grafting assay indicates that the late flowering of pho1 mutants is a result of impaired phosphate translocation from roots to shoots. Knockout mutation of SPX1 and SPX2, two negative regulators of the phosphate starvation response, partially rescues the late flowering of pho1 mutants. PHO1 is epistatic to PHO2, a negative regulator of PHO1, in flowering time regulation. Loss of PHO1 represses the expression of some floral activators, including FT encoding florigen, and induces the expression of some floral repressors in shoots. Genetic analyses indicate that at least jasmonic acid signaling is partially responsible for the late flowering of pho1 mutants. In addition, we find that rice PHO1;2, the homolog of PHO1, plays a similar role in floral transition. These results suggest that PHO1 integrates phosphorus nutrition and flowering time, and could be used as a potential target in modulating phosphorus nutrition-mediated flowering time in plants.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Flores , Proteínas de Transporte de Fosfato , Fosfatos , Raíces de Plantas , Brotes de la Planta , Arabidopsis/genética , Arabidopsis/fisiología , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fosfatos/metabolismo , Fosfatos/deficiencia , Flores/crecimiento & desarrollo , Flores/genética , Flores/fisiología , Flores/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/fisiología , Raíces de Plantas/genética , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Brotes de la Planta/genética , Brotes de la Planta/fisiología , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Regulación de la Expresión Génica de las Plantas , Mutación , Transporte Biológico

RESUMEN

The use of probiotic lactobacilli has been proposed as a strategy to mitigate damage associated with exposure to toxic metals. Their protective effect against cationic metal ions, such as those of mercury or lead, is believed to stem from their chelating and accumulating potential. However, their retention of anionic toxic metalloids, such as inorganic arsenic, is generally low. Through the construction of mutants in phosphate transporter genes (pst) in Lactiplantibacillus plantarum and Lacticaseibacillus paracasei strains, coupled with arsenate [As(V)] uptake and toxicity assays, we determined that the incorporation of As(V), which structurally resembles phosphate, is likely facilitated by phosphate transporters. Surprisingly, inactivation in Lc. paracasei of PhoP, the transcriptional regulator of the two-component system PhoPR, a signal transducer involved in phosphate sensing, led to an increased resistance to arsenite [As(III)]. In comparison to the wild type, the phoP strain exhibited no differences in the ability to retain As(III), and there were no observed changes in the oxidation of As(III) to the less toxic As(V). These results reinforce the idea that specific transport, and not unspecific cell retention, plays a role in As(V) biosorption by lactobacilli, while they reveal an unexpected phenotype for the lack of the pleiotropic regulator PhoP.

Asunto(s)

Arsénico , Fosfatos , Fosfatos/metabolismo , Arsénico/toxicidad , Arsénico/metabolismo , Lactobacillus/metabolismo , Lactobacillus/efectos de los fármacos , Lactobacillus/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Arseniatos/metabolismo , Arseniatos/toxicidad

RESUMEN

Phosphorus (P) is a vital nutrient element that is essential for plant growth and development, and arbuscular mycorrhizal fungi (AMF) can significantly enhance P absorption. The phosphate transporter protein 1 (PHT1) family mediates the uptake of P in plants. However, the PHT1 gene has not yet been characterized in Salvia miltiorrhiza. In this study, to gain insight into the functional divergence of PHT1 genes, nine SmPHT1 genes were identified in the S. miltiorrhiza genome database via bioinformatics tools. Phylogenetic analysis revealed that the PHT1 proteins of S. miltiorrhiza, Arabidopsis thaliana, and Oryza sativa could be divided into three groups. PHT1 in the same clade has a similar gene structure and motif, suggesting that the features of each clade are relatively conserved. Further tissue expression analysis revealed that SmPHT1 was expressed mainly in the roots and stems. In addition, phenotypic changes, P content, and PHT1 gene expression were analyzed in S. miltiorrhiza plants inoculated with AMF under different P conditions (0 mM, 0.1 mM, and 10 mM). P stress and AMF significantly affected the growth and P accumulation of S. miltiorrhiza. SmPHT1;6 was strongly expressed in the roots colonized by AMF, implying that SmPHT1;6 was a specific AMF-inducible PHT1. Taken together, these results provide new insights into the functional divergence and genetic redundancy of the PHT1 genes in response to P stress and AMF symbiosis in S. miltiorrhiza.

Asunto(s)

Regulación de la Expresión Génica de las Plantas , Micorrizas , Proteínas de Transporte de Fosfato , Proteínas de Plantas , Salvia miltiorrhiza , Simbiosis , Genoma de Planta , Familia de Multigenes , Micorrizas/genética , Micorrizas/fisiología , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Fosfatos/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/microbiología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Salvia miltiorrhiza/genética , Salvia miltiorrhiza/microbiología , Salvia miltiorrhiza/fisiología , Estrés Fisiológico

RESUMEN

Phosphate is a key component of mineralized tissues and is also part of many organic compounds. Phosphorus homeostasis depends especially upon intestinal absorption, and renal excretion, which are regulated by various hormones, such as PTH, 1,25-dihydroxyvitamin D, and fibroblast growth factor 23. In this review we provide an update of several genetic disorders that affect phosphate transporters through cell membranes or the phosphate-regulating hormones, and, consequently, result in hypophosphatemia.

Asunto(s)

Factor-23 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos , Hipofosfatemia , Hormona Paratiroidea , Humanos , Hipofosfatemia/genética , Hipofosfatemia/etiología , Factores de Crecimiento de Fibroblastos/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Hormona Paratiroidea/metabolismo , Fosfatos/metabolismo , Vitamina D/metabolismo , Vitamina D/análogos & derivados , Proteínas Klotho , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Endopeptidasa Neutra Reguladora de Fosfato PHEX/genética , Absorción Intestinal/genética , Glucuronidasa/genética , Glucuronidasa/metabolismo , Fósforo/metabolismo

RESUMEN

Phosphorus (P), a macronutrient, plays key roles in plant growth, development, and yield. Phosphate (Pi) transporters (PHTs) and PHOSPHATE1 (PHO1) are central to Pi acquisition and distribution. Potentially, PHO1 is also involved in signal transduction under low P. The current study was designed to identify and functionally characterize the PHO1 gene family in chickpea (CaPHO1s). Five CaPHO1 genes were identified through a comprehensive genome-wide search. Phylogenetically, CaPHO1s formed two clades, and protein sequence analyses confirmed the presence of conserved domains. CaPHO1s are expressed in different plant organs including root nodules and are induced by Pi-limiting conditions. Functional complementation of atpho1 mutant with three CaPHO1 members, CaPHO1, CaPHO1;like, and CaPHO1;H1, independently demonstrated their role in root to shoot Pi transport, and their redundant functions. To further validate this, we raised independent RNA-interference (RNAi) lines of CaPHO1, CaPHO1;like, and CaPHO1;H1 along with triple mutant line in chickpea. While single gene RNAi lines behaved just like WT, triple knock-down RNAi lines (capho1/like/h1) showed reduced shoot growth and shoot Pi content. Lastly, we showed that CaPHO1s are involved in root nodule development and Pi content. Our findings suggest that CaPHO1 members function redundantly in root to shoot Pi export and root nodule development in chickpea.

Asunto(s)

Cicer , Proteínas de Plantas , Nodulación de la Raíz de la Planta , Cicer/genética , Cicer/metabolismo , Cicer/crecimiento & desarrollo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nodulación de la Raíz de la Planta/genética , Regulación de la Expresión Génica de las Plantas , Fosfatos/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Raíces de Plantas/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Filogenia , Transporte Biológico/genética , Familia de Multigenes

RESUMEN

The suprachiasmatic nucleus (SCN) encodes time of day through changes in daily firing; however, the molecular mechanisms by which the SCN times behavior are not fully understood. To identify factors that could encode day/night differences in activity, we combine patch-clamp recordings and single-cell sequencing of individual SCN neurons in mice. We identify PiT2, a phosphate transporter, as being upregulated in a population of Vip+Nms+ SCN neurons at night. Although nocturnal and typically showing a peak of activity at lights off, mice lacking PiT2 (PiT2-/-) do not reach the activity level seen in wild-type mice during the light/dark transition. PiT2 loss leads to increased SCN neuronal firing and broad changes in SCN protein phosphorylation. PiT2-/- mice display a deficit in seasonal entrainment when moving from a simulated short summer to longer winter nights. This suggests that PiT2 is responsible for timing activity and is a driver of SCN plasticity allowing seasonal entrainment.

Asunto(s)

Núcleo Supraquiasmático , Animales , Núcleo Supraquiasmático/metabolismo , Ratones , Neuronas/metabolismo , Locomoción , Ratones Endogámicos C57BL , Péptido Intestinal Vasoactivo/metabolismo , Masculino , Ritmo Circadiano/fisiología , Fotoperiodo , Ratones Noqueados , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo III/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo III/genética , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética

RESUMEN

The mitochondrial phosphate carrier is critical for adenosine triphosphate synthesis by serving as the primary means for mitochondrial phosphate import across the inner membrane. Variants in the SLC25A3 gene coding mitochondrial phosphate carrier lead to failure in inorganic phosphate transport across mitochondria. The critical dependence on mitochondria as an energy source is especially evident in tissues with high-energy demands such as the heart, muscle; defects in the mitochondrial energy production machinery underlie a wide range of primary mitochondrial disorders that present with cardiac and muscle diseases. The characteristic clinical picture of a prominent early-onset hypertrophic cardiomyopathy and lactic acidosis may be an indication for analysis of the SLC25A3 gene. Here, described a patient with suspicion of infantile Pompe disease due to involvement of heart and muscle and high-level of plasma creatinine kinase but finally diagnosed mitochondrial phosphate-carrier deficiency.

Asunto(s)

Enfermedad del Almacenamiento de Glucógeno Tipo II , Mitocondrias , Proteínas de Transporte de Fosfato , Humanos , Enfermedad del Almacenamiento de Glucógeno Tipo II/genética , Enfermedad del Almacenamiento de Glucógeno Tipo II/diagnóstico , Enfermedad del Almacenamiento de Glucógeno Tipo II/patología , Proteínas de Transporte de Fosfato/genética , Mitocondrias/genética , Mitocondrias/metabolismo , Mitocondrias/patología , Lactante , Enfermedades Mitocondriales/genética , Enfermedades Mitocondriales/diagnóstico , Enfermedades Mitocondriales/patología , Mutación/genética , Diagnóstico Diferencial , Masculino , Femenino , Fosfatos/sangre , Fosfatos/metabolismo , Acidosis Láctica/genética , Acidosis Láctica/diagnóstico

RESUMEN

Arsenic (As) contamination in soil poses a potential threat to human health via crop uptake. As-hyperaccumulator Pteris vittata serves as a model plant to study As uptake and associated mechanisms. This study focuses on a novel P/AsV transport system mediated by low-affinity phosphate transporter-B 1 family (PTB1) in P. vittata. Here, we identified two plasma-membrane-localized PTB1 genes, PvPTB1;1/1;2, in vascular plants for the first time, which were 4.4-40-fold greater in expression in P. vittata than in other Pteris ferns. Functional complementation of a yeast P-uptake mutant and enhanced P accumulation in transgenic Arabidopsis thaliana confirmed their role in P uptake. Moreover, the expression of PvPTB1;1/1;2 facilitated the transport and accumulation of As in both yeast and A. thaliana shoots, demonstrating a comparable AsV uptake capacity. Microdissection-qPCR analysis and single-cell transcriptome analysis collectively suggest that PvPTB1;1/1;2 are specifically expressed in the epidermal cells of P. vittata roots. PTB1 may play a pivotal role in efficient P recycling during phytate secretion and hydrolysis in P. vittata roots. In summary, the dual P transport mechanisms consisting of high-affinity Pht1 and low-affinity PTB1 may have contributed to the efficient P/As uptake in P. vittata, thereby contributing to efficient phytoremediation for As-contaminated soils.

Asunto(s)

Arsénico , Proteínas de Transporte de Fosfato , Fosfatos , Pteris , Pteris/metabolismo , Pteris/genética , Arsénico/metabolismo , Fosfatos/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Arabidopsis/metabolismo , Arabidopsis/genética , Contaminantes del Suelo/metabolismo , Transporte Biológico

RESUMEN

Phosphate homeostasis is essential for all living organisms. Low-affinity phosphate transporters are involved in phosphate import and regulation in a range of eukaryotic organisms. We have determined the structures of the Saccharomyces cerevisiae phosphate importer Pho90 by electron cryomicroscopy in two complementary states at 2.3 and 3.1 Å resolution. The symmetrical, outward-open structure in the presence of phosphate indicates bound substrate ions in the binding pocket. In the absence of phosphate, Pho90 assumes an asymmetric structure with one monomer facing inward and one monomer facing outward, providing insights into the transport mechanism. The Pho90 transport domain binds phosphate ions on one side of the membrane, then flips to the other side where the substrate is released. Together with functional experiments, these complementary structures illustrate the transport mechanism of eukaryotic low-affinity phosphate transporters.

Asunto(s)

Microscopía por Crioelectrón , Modelos Moleculares , Proteínas de Transporte de Fosfato , Fosfatos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Fosfatos/metabolismo , Fosfatos/química , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/química , Sitios de Unión , Unión Proteica , Transporte Biológico

RESUMEN

Endogenous retroviruses (ERVs) are remnants of ancestral viral infections. Feline leukemia virus (FeLV) is an exogenous and endogenous retrovirus in domestic cats. It is classified into several subgroups (A, B, C, D, E, and T) based on viral receptor interference properties or receptor usage. ERV-derived molecules benefit animals, conferring resistance to infectious diseases. However, the soluble protein encoded by the defective envelope (env) gene of endogenous FeLV (enFeLV) functions as a co-factor in FeLV subgroup T infections. Therefore, whether the gene emerged to facilitate viral infection is unclear. Based on the properties of ERV-derived molecules, we hypothesized that the defective env genes possess antiviral activity that would be advantageous to the host because FeLV subgroup B (FeLV-B), a recombinant virus derived from enFeLV env, is restricted to viral transmission among domestic cats. When soluble truncated Env proteins from enFeLV were tested for their inhibitory effects against enFeLV and FeLV-B, they inhibited viral infection. Notably, this antiviral machinery was extended to infection with the Gibbon ape leukemia virus, Koala retrovirus A, and Hervey pteropid gammaretrovirus. Although these viruses used feline phosphate transporter 1 (fePit1) and phosphate transporter 2 as receptors, the inhibitory mechanism involved competitive receptor binding in a fePit1-dependent manner. The shift in receptor usage might have occurred to avoid the inhibitory effect. Overall, these findings highlight the possible emergence of soluble truncated Env proteins from enFeLV as a restriction factor against retroviral infection and will help in developing host immunity and antiviral defense by controlling retroviral spread.IMPORTANCERetroviruses are unique in using reverse transcriptase to convert RNA genomes into DNA, infecting germ cells, and transmitting to offspring. Numerous ancient retroviral sequences are known as endogenous retroviruses (ERVs). The soluble Env protein derived from ERVs functions as a co-factor that assists in FeLV-T infection. However, herein, we show that the soluble Env protein exhibits antiviral activity and provides resistance to mammalian retrovirus infection through competitive receptor binding. In particular, this finding may explain why FeLV-B transmission is not observed among domestic cats. ERV-derived molecules can benefit animals in an evolutionary arms race, highlighting the double-edged-sword nature of ERVs.

Asunto(s)

Productos del Gen env , Virus de la Leucemia Felina , Leucemia Felina , Animales , Gatos , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Productos del Gen env/genética , Productos del Gen env/metabolismo , Virus de la Leucemia Felina/clasificación , Virus de la Leucemia Felina/genética , Virus de la Leucemia Felina/metabolismo , Virus de la Leucemia del Gibón/genética , Virus de la Leucemia del Gibón/metabolismo , Leucemia Felina/genética , Leucemia Felina/metabolismo , Leucemia Felina/virología , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Receptores Virales/metabolismo , Infecciones por Retroviridae/metabolismo , Infecciones por Retroviridae/virología , Solubilidad , Femenino

RESUMEN

The NACHT, leucine-rich repeat, and pyrin domains-containing protein 3 (collectively known as NLRP3) inflammasome activation plays a critical role in innate immune and pathogenic microorganism infections. However, excessive activation of NLRP3 inflammasome will lead to cellular inflammation and tissue damage, and naturally it must be precisely controlled in the host. Here, we discovered that solute carrier family 25 member 3 (SLC25A3), a mitochondrial phosphate carrier protein, plays an important role in negatively regulating NLRP3 inflammasome activation. We found that SLC25A3 could interact with NLRP3, overexpression of SLC25A3 and knockdown of SLC25A3 could regulate NLRP3 inflammasome activation, and the interaction of NLRP3 and SLC25A3 is significantly boosted in the mitochondria when the NLRP3 inflammasome is activated. Our detailed investigation demonstrated that the interaction between NLRP3 and SLC25A3 disrupted the interaction of NLRP3-NEK7, promoted ubiquitination of NLRP3, and negatively regulated NLRP3 inflammasome activation. Thus, these findings uncovered a new regulatory mechanism of NLRP3 inflammasome activation, which provides a new perspective for the therapy of NLRP3 inflammasome-associated inflammatory diseases.

Asunto(s)

Inflamasomas , Proteínas Mitocondriales , Proteína con Dominio Pirina 3 de la Familia NLR , Proteínas de Transporte de Fosfato , Animales , Humanos , Ratones , Células HEK293 , Inflamasomas/metabolismo , Mitocondrias/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Ubiquitinación , Línea Celular , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Técnicas de Silenciamiento del Gen

RESUMEN

Per- and polyfluoroalkyl substances (PFASs), with significant health risks to humans and wildlife, bioaccumulate in plants. However, the mechanisms underlying plant uptake remain poorly understood. This study deployed transcriptomic analysis coupled with genetic and physiological studies using Arabidopsis to investigate how plants respond to perfluorooctanesulfonic acid (PFOS), a long-chain PFAS. We observed increased expressions of genes involved in plant uptake and transport of phosphorus, an essential plant nutrient, suggesting intertwined uptake and transport processes of phosphorus and PFOS. Furthermore, PFOS-altered response differed from the phosphorus deficiency response, disrupting phosphorus metabolism to increase phosphate transporter (PHT) transcript. Interestingly, pht1;2 and pht1;8 mutants showed reduced sensitivity to PFOS compared to that of the wild type, implying an important role of phosphate transporters in PFOS sensing. Furthermore, PFOS accumulated less in the shoots of the pht1;8 mutant, indicating the involvement of PHT1;8 protein in translocating PFOS from roots to shoots. Supplementing phosphate improved plant's tolerance to PFOS and reduced PFOS uptake, suggesting that manipulating the phosphate source in PFOS-contaminated soils may be a promising strategy for minimizing PFOS uptake by edible crops or promoting PFOS uptake during phytoremediation. This study highlighted the critical role of phosphate sensing and transport system in the uptake and translocation of PFOS in plants.

Asunto(s)

Ácidos Alcanesulfónicos , Arabidopsis , Fluorocarburos , Humanos , Fosfatos , Redes Reguladoras de Genes , Regulación de la Expresión Génica de las Plantas , Arabidopsis/genética , Arabidopsis/metabolismo , Fósforo/metabolismo , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo

RESUMEN

Meropenem (MEPM) is used for the treatment of serious infectious diseases solely as. INJECTABLE: Therefore, the development of an oral formulation would expand its clinical utility. To this end, an exact understanding of the absorption characteristics of MEPM is essential. In this study, MEPM absorption in the rat small intestine was investigated using an in situ loop technique and an in vitro diffusion chamber method. The disappearance ratios of MEPM (0.1 mM) were in the order of ileum > duodenum > jejunum. The extensive MEPM disappearance in the ileum was significantly reduced in the presence of foscarnet, a Na+-dependent phosphate transporter (NaPi-T) substrate, whereas glycylsarcosine, thiamine, taurocholic acid, and biapenem had no effects. The mucosal-to-serosal (M-to-S) permeation of MEPM across the rat ileal segments was very small under normal experimental conditions. However, on addition of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) to the experimental medium, the M-to-S permeation of MEPM markedly increased, showing a more than 7-fold greater apparent permeation coefficient. The present results suggest that MEPM is preferentially absorbed in the rat ileum, sharing with foscarnet, and that 1,25(OH)2D3 potentially activates the absorption of MEPM there. A likely candidate for involvement in MEPM absorption was NaPi-T or a related transporter.

Asunto(s)

Foscarnet , Proteínas de Transporte de Fosfato , Vitamina D/análogos & derivados , Ratas , Animales , Foscarnet/farmacología , Meropenem/farmacología , Íleon , Absorción Intestinal