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1.
Plant Cell ; 36(5): 1892-1912, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38262703

RESUMO

In cereal grains, starch is synthesized by the concerted actions of multiple enzymes on the surface of starch granules within the amyloplast. However, little is known about how starch-synthesizing enzymes access starch granules, especially for amylopectin biosynthesis. Here, we show that the rice (Oryza sativa) floury endosperm9 (flo9) mutant is defective in amylopectin biosynthesis, leading to grains exhibiting a floury endosperm with a hollow core. Molecular cloning revealed that FLO9 encodes a plant-specific protein homologous to Arabidopsis (Arabidopsis thaliana) LIKE EARLY STARVATION1 (LESV). Unlike Arabidopsis LESV, which is involved in starch metabolism in leaves, OsLESV is required for starch granule initiation in the endosperm. OsLESV can directly bind to starch by its C-terminal tryptophan (Trp)-rich region. Cellular and biochemical evidence suggests that OsLESV interacts with the starch-binding protein FLO6, and loss-of-function mutations of either gene impair ISOAMYLASE1 (ISA1) targeting to starch granules. Genetically, OsLESV acts synergistically with FLO6 to regulate starch biosynthesis and endosperm development. Together, our results identify OsLESV-FLO6 as a non-enzymatic molecular module responsible for ISA1 localization on starch granules, and present a target gene for use in biotechnology to control starch content and composition in rice endosperm.


Assuntos
Endosperma , Regulação da Expressão Gênica de Plantas , Oryza , Proteínas de Plantas , Amido , Oryza/genética , Oryza/metabolismo , Oryza/crescimento & desenvolvimento , Endosperma/metabolismo , Endosperma/genética , Amido/metabolismo , Amido/biossíntese , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Amilopectina/metabolismo , Mutação , Plantas Geneticamente Modificadas
2.
Small ; : e2404893, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39105465

RESUMO

Vanadium-based compounds have attracted significant attention as cathodes for aqueous zinc metal batteries (AZMBs) because of their remarkable advantages in specific capacities. However, their low diffusion coefficient for zinc ions and structural collapse problems lead to poor rate capability and cycle stability. In this work, bilayered Sr0.25V2O5·0.8H2O (SVOH) nanowires are first reported as a highly stable cathode material for rechargeable AZMBs. The synergistic pillaring effect of strontium ions and water molecules improves the structural stability and ion transport dynamics of vanadium-based compounds. Consequently, the SVOH cathode exhibits a high capacity of 325.6 mAh g-1 at 50 mA g-1, with a capacity retention rate of 72.6% relative to the maximum specific capacity at 3.0 A g-1 after 3000 cycles. Significantly, a unique single-nanowire device is utilized to demonstrate the excellent conductivity of the SVOH cathode directly. Additionally, the energy storage mechanism of zinc insertion and extraction is investigated using a variety of advanced in situ and ex situ analysis techniques. This method of ion intercalation to improve electrochemical performance will further promote the development of AZMBs in large-scale applications.

3.
Plant Biotechnol J ; 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39180364

RESUMO

Starch is synthesized as insoluble, semicrystalline particles within plant chloroplast and amyloplast, which are referred to as starch grains (SGs). The size and morphology of SGs in the cereal endosperm are diverse and species-specific, representing a key determinant of the suitability of starch for industrial applications. However, the molecular mechanisms modulating SG size in cereal endosperm remain elusive. Here, we functionally characterized the rice (Oryza sativa) mutant substandard starch grain7 (ssg7), which exhibits enlarged SGs and defective endosperm development. SSG7 encodes a plant-specific DUF1001 domain-containing protein homologous to Arabidopsis (Arabidopsis thaliana) CRUMPLED LEAF (AtCRL). SSG7 localizes to the amyloplast membrane in developing endosperm. Several lines of evidence suggest that SSG7 functions together with SSG4 and SSG6, known as two regulators essential for SG development, to control SG size, by interacting with translocon-associated components, which unveils a molecular link between SG development and protein import. Genetically, SSG7 acts synergistically with SSG4 and appears to be functional redundancy with SSG6 in modulating SG size and endosperm development. Collectively, our findings uncover a multimeric functional protein complex involved in SG development in rice. SSG7 represents a promising target gene for the biotechnological modification of SG size, particularly for breeding programs aimed at improving starch quality.

4.
Chemphyschem ; : e202400821, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352043

RESUMO

Rechargeable magnesium batteries (RMBs) have gradually got attention due to the high theoretical capacity, low cost and high security. However, the lack of suitable cathode materials has been a major obstacle to the development of RMBs. Transition metal sulfides (TMSs) have been studied extensively because of their high theoretical specific capacity and other advantages. However, the diffusion rate of Mg2+ in TMSs is slow and side reactions are easy to occur. In this work, soft anion doping strategy was adopted at Co4S3 cathode material. After doping the appropriate content of Se, it showed the specific capacity of 248 mAh g-1 at a current density of 100 mA g-1. The mechanism of magnesium storage was investigated by ex-situ technique. This work laid a foundation for researching cobalt-based sulfide in cathode materials of RMBs.

5.
Sensors (Basel) ; 24(12)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38931811

RESUMO

The maximum detection distance is usually the primary concern of magnetic anomaly detection (MAD). Intuition tells us that larger object size, stronger magnetization and finer measurement resolution guarantee a further detectable distance. However, the quantitative relationship between detection distance and the above determinants is seldom studied. In this work, unmanned aerial vehicle-based MAD field experiments are conducted on cargo vessels and NdFeB magnets as typical magnetic objects to give a set of visualized magnetic field flux density images. Isometric finite element models are established, calibrated and analyzed according to the experiment configuration. A maximum detectable distance map as a function of target size and measurement resolution is then obtained from parametric sweeping on an experimentally calibrated finite element analysis model. We find that the logarithm of detectable distance is positively proportional to the logarithm of object size while negatively proportional to the logarithm of resolution, within the ranges of 1 m~500 m and 1 pT~1 µT, respectively. A three-parameter empirical formula (namely distance-size-resolution logarithmic relationship) is firstly developed to determine the most economic sensor configuration for a given detection task, to estimate the maximum detection distance for a given magnetic sensor and object, or to evaluate minimum detectable object size at a given magnetic anomaly detection scenario.

6.
Mol Psychiatry ; 27(10): 4123-4135, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35444255

RESUMO

The intricate processes of microbiota-gut-brain communication in modulating human cognition and emotion, especially in the context of mood disorders, have remained elusive. Here we performed faecal metagenomic, serum metabolomics and neuroimaging studies on a cohort of 109 unmedicated patients with depressed bipolar disorder (BD) patients and 40 healthy controls (HCs) to characterise the microbial-gut-brain axis in BD. Across over 12,000 measured metabolic features, we observed a large discrepancy (73.54%) in the serum metabolome between BD patients and HCs, spotting differentially abundant microbial-derived neuroactive metabolites including multiple B-vitamins, kynurenic acid, gamma-aminobutyric acid and short-chain fatty acids. These metabolites could be linked to the abundance of gut microbiota presented with corresponding biosynthetic potentials, including Akkermansia muciniphila, Citrobacter spp. (Citrobacter freundii and Citrobacter werkmanii), Phascolarctobacterium spp., Yersinia spp. (Yersinia frederiksenii and Yersinia aleksiciae), Enterobacter spp. (Enterobacter cloacae and Enterobacter kobei) and Flavobacterium spp. Based on functional neuroimaging, BD-related neuroactive microbes and metabolites were discovered as potential markers associated with BD-typical features of functional connectivity of brain networks, hinting at aberrant cognitive function, emotion regulation, and interoception. Our study combines gut microbiota and neuroactive metabolites with brain functional connectivity, thereby revealing potential signalling pathways from the microbiota to the gut and the brain, which may have a role in the pathophysiology of BD.


Assuntos
Transtorno Bipolar , Microbioma Gastrointestinal , Microbiota , Humanos , Microbioma Gastrointestinal/genética , Transtorno Bipolar/metabolismo , Eixo Encéfalo-Intestino , Metaboloma , Encéfalo/metabolismo
7.
Nanotechnology ; 34(30)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37094562

RESUMO

Lithium supply shortages have prompted the search for alternatives to widespread grid system applications. Potassium-ion batteries (PIBs) have emerged to promising candidates for this purpose. Nonetheless, the large radius of K+(1.38 Å) impedes the march of satisfactory cathode materials. Here, we used solid-phase synthesis to prepare a layered K0.37MnO2·0.25H2O (KMO) cathode, comprising alternately connected MnO6octahedra with a large interlayer spacing (0.71 nm) to accommodate the migration and transport of K+ions. The cathode material achieved initial specific capacities of 102.3 and 88.1 mA h g-1at current densities of 60 mA g-1and 1 A g-1, respectively. The storage mechanism of K+ions in PIBs was demonstratedex situusing x-ray diffraction, x-ray photoelectron spectroscopy, and Raman spectroscopy measurements. Overall, our proposed KMO was confirmed as an auspicious cathode material for potential use in PIBs.

8.
J Immunol ; 206(5): 1013-1026, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33462138

RESUMO

There is currently no effective vaccine against leishmaniasis because of the lack of sufficient knowledge about the Ags that stimulate host-protective and long-lasting T cell-mediated immunity. We previously identified Leishmania phosphoenolpyruvate carboxykinase (PEPCK, a gluconeogenic enzyme) as an immunodominant Ag that is expressed by both the insect (promastigote) and mammalian (amastigote) stages of the parasite. In this study, we investigated the role of PEPCK in metabolism, virulence, and immunopathogenicity of Leishmania major We show that targeted loss of PEPCK results in impaired proliferation of L. major in axenic culture and bone marrow-derived macrophages. Furthermore, the deficiency of PEPCK results in highly attenuated pathology in vivo. BALB/c mice infected with PEPCK-deficient parasites failed to develop any cutaneous lesions despite harboring parasites at the cutaneous site of infection. This was associated with a dramatic reduction in the frequency of cytokine (IFN-γ, IL-4, and IL-10)-producing CD4+ T cells in spleens and lymph nodes draining the infection site. Cells from mice infected with PEPCK-deficient parasites also produced significantly low levels of these cytokines into the culture supernatant following in vitro restimulation with soluble Leishmania Ag. PEPCK-deficient parasites exhibited significantly greater extracellular acidification rate, increased proton leak, and decreased ATP-coupling efficiency and oxygen consumption rates in comparison with their wild-type and addback counterparts. Taken together, these results show that PEPCK is a critical metabolic enzyme for Leishmania, and its deletion results in altered metabolic activity and attenuation of virulence.


Assuntos
Leishmania major/metabolismo , Leishmania major/patogenicidade , Leishmaniose Cutânea/parasitologia , Fosfoenolpiruvato/metabolismo , Fatores de Virulência/metabolismo , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/parasitologia , Citocinas/imunologia , Feminino , Imunidade Celular/imunologia , Leishmania major/imunologia , Leishmaniose Cutânea/imunologia , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos SCID , Camundongos Transgênicos , Fosfoenolpiruvato/imunologia , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/metabolismo , Fatores de Virulência/imunologia
9.
Cell Mol Biol (Noisy-le-grand) ; 69(13): 8-15, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38158695

RESUMO

We discussed the expression and biological functions of the SAPCD2X1 protein in the HCT116 CRC cell line by bioinformatics analysis and prediction, and biological function verification. Spatial conformation models of SAPCD2X1 and SAPCD2 were predicted using the threading method, ensemble method, and several other protein structure prediction approaches. The conformational similarity between SAPCD2X1 and SAPCD2 was studied, and their functions were predicted. The biological experiments showed that SAPCD2X1 and SAPCD2 were overexpressed in CRC cells. SAPCD2X1-specific antibodies were prepared. The expressions of SAPCD2X1 and SAPCD2 were localized in cells using the immunofluorescence assay. The SAPCD2 and SAPCD2X1 overexpression models were validated using Western Blot and RT-qPCR. We successfully predicted the structures of the SAPCD2X1 and SAPCD2 proteins, and visualized them using the VDM software. It was predicted that the tertiary structure of SAPCD2X1 changed significantly compared with SAPCD2. Alteration of the biological functions of SAPCD2X1 was also predicted due to the changes in the spatial conformation of the protein. Anti-SAPCD2X1 antibody and SAPCD2X1-EGFP and SAPCD2-EGFP recombinant plasmids were established. The overexpression of the two proteins was induced in HCT116 cells using the recombinant plasmids, and verified by RT-qPCR and Western Blot. Meanwhile, the anti-SAPCD2X1 antibody was proved to have a high specificity. The immunofluorescence assay showed that SAPCD2X1 and SAPCD2 are mainly expressed in the cytoplasm. SAPCD2X1 and SAPCD2 exhibited significantly different biological functions in HCT116 cells. SAPCD2 is a carcinogenic protein, while SAPCD2X1 does not affect the proliferation, invasion, and migration of human CRC HCT116 cells.


Assuntos
Neoplasias Colorretais , MicroRNAs , Proteínas Nucleares , Humanos , Carcinogênese , Carcinógenos , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HCT116 , MicroRNAs/metabolismo , Proteínas Nucleares/genética
10.
Hered Cancer Clin Pract ; 21(1): 18, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37773168

RESUMO

INTRODUCTION: We present a case of a male patient with neurofibromatosis type 1 diagnosed with pancreatic divisum and several gastrointestinal tumors. A 55-year-old man was admitted to the hospital with recurrent chronic pancreatitis, indicating a large mass in the ampulla. In addition, genetic testing revealed two unique germline mutations in the neurofibromin (NF1) gene, and their potential interaction in promoting cancer was further investigated. CONCLUSION: The first similar case was reported in 2020. The current case was distinct from other cases since an additional two NF1 mutations were found in the patient. In conjunction with prior case reports, our findings imply that genetic testing in patients diagnosed with neurofibromatosis type 1 could be helpful in the development of effective treatments.

11.
Sensors (Basel) ; 23(13)2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37447711

RESUMO

Magnetic current imaging is deemed an emerging powerful technique for visualizing electrical currents in electronic devices. However, the existing magnetic-field-based Fourier Transform back-evolution method is limited by its mono-function of imaging the magnitude of current density in devices under test, and subject to background noise distortion. Here, we developed a novel vectorial current density imaging method based on the detection of the magnetic field gradient generated by current carrying conductors. A closed form solution of current density inversion was analytically derived and numerically verified. Experiments were conducted by scanning tri-axial fluxgate sensor over different shapes of electrical wires. The results show that a current density resolution of 24.15 mA/mm2, probe-to-sample separation of 2 mm, and spatial resolution of 0.69 mm were achieved over a maximum scanning area of 300 mm × 300 mm. Such a method is verified to be capable of simultaneously imaging both magnitude and directions of current density, which is a promising technique for in situ noninvasive inspection for the power electronic and semiconductor industry.


Assuntos
Imageamento por Ressonância Magnética , Magnetismo , Imageamento por Ressonância Magnética/métodos , Imagens de Fantasmas , Campos Magnéticos , Análise de Fourier
12.
J Environ Manage ; 342: 118303, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37276617

RESUMO

This study investigates the indicative role of oxidation-reduction potential (ORP) and pH of hydrocarbon-contaminated soils on their shear characteristics, contributing to safer and more efficient ex-situ remediation and management processes. The presence of hydrocarbons alters the soil's shear strength by affecting the hydration shell thickness, fluid's dielectric properties, and ion/electron exchange, as well as the soil's electrochemical force, which in turn affects the ORP and pH. The relationship between hydrocarbon concentrations in contaminated soils (0.1-15%) and corresponding ORP/pH values could be fitted linearly with a good correlation coefficient r (0.978), highlighting the potential of ORP/pH as an indicator for pollutant occurrence. Furthermore, the relationships between ORP/pH and shear strength, as tested in our study and obtained after processing from relevant literature sources, exhibited a strong fit (r = 0.976-0.995). The Mohr-Coulomb criterion modified using the ORP/pH parameter was established, which could improve the fitting effect of these relationships (r = 0.988-0.996), verifying the reliability of the novel criterion and application feasibility of ORP/pH. In future research, this modified criterion can be employed to conveniently assess the shear strength of contaminated soil by considering the shear behaviour of virgin soil and the ORP/pH values of the contaminated soil.


Assuntos
Poluentes do Solo , Solo , Solo/química , Estudos de Viabilidade , Reprodutibilidade dos Testes , Hidrocarbonetos , Oxirredução , Poluentes do Solo/química
13.
Am J Hum Genet ; 105(6): 1102-1111, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31679651

RESUMO

Recurrent miscarriage (RM) affects millions of couples globally, and half of them have no demonstrated etiology. Genome sequencing (GS) is an enhanced and novel cytogenetic tool to define the contribution of chromosomal abnormalities in human diseases. In this study we evaluated its utility in RM-affected couples. We performed low-pass GS retrospectively for 1,090 RM-affected couples, all of whom had routine chromosome analysis. A customized sequencing and interpretation pipeline was developed to identify chromosomal rearrangements and deletions/duplications with confirmation by fluorescence in situ hybridization, chromosomal microarray analysis, and PCR studies. Low-pass GS yielded results in 1,077 of 1,090 couples (98.8%) and detected 127 chromosomal abnormalities in 11.7% (126/1,077) of couples; both members of one couple were identified with inversions. Of the 126 couples, 39.7% (50/126) had received former diagnostic results by karyotyping characteristic of normal human male or female karyotypes. Low-pass GS revealed additional chromosomal abnormalities in 50 (4.0%) couples, including eight with balanced translocations and 42 inversions. Follow-up studies of these couples showed a higher miscarriage/fetal-anomaly rate of 5/10 (50%) compared to 21/93 (22.6%) in couples with normal GS, resulting in a relative risk of 2.2 (95% confidence interval, 1.1 to 4.6). In these couples, this protocol significantly increased the diagnostic yield of chromosomal abnormalities per couple (11.7%) in comparison to chromosome analysis (8.0%, chi-square test p = 0.000751). In summary, low-pass GS identified underlying chromosomal aberrations in 1 in 9 RM-affected couples, enabling identification of a subgroup of couples with increased risk of subsequent miscarriage who would benefit from a personalized intervention.


Assuntos
Aborto Habitual/diagnóstico , Aborto Habitual/genética , Aberrações Cromossômicas , Sequenciamento Completo do Genoma/métodos , Adulto , Feminino , Seguimentos , Humanos , Cariotipagem , Masculino , Gravidez , Prognóstico , Estudos Retrospectivos
14.
Genome Res ; 29(5): 798-808, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30940689

RESUMO

Here, we describe single-tube long fragment read (stLFR), a technology that enables sequencing of data from long DNA molecules using economical second-generation sequencing technology. It is based on adding the same barcode sequence to subfragments of the original long DNA molecule (DNA cobarcoding). To achieve this efficiently, stLFR uses the surface of microbeads to create millions of miniaturized barcoding reactions in a single tube. Using a combinatorial process, up to 3.6 billion unique barcode sequences were generated on beads, enabling practically nonredundant cobarcoding with 50 million barcodes per sample. Using stLFR, we demonstrate efficient unique cobarcoding of more than 8 million 20- to 300-kb genomic DNA fragments. Analysis of the human genome NA12878 with stLFR demonstrated high-quality variant calling and phase block lengths up to N50 34 Mb. We also demonstrate detection of complex structural variants and complete diploid de novo assembly of NA12878. These analyses were all performed using single stLFR libraries, and their construction did not significantly add to the time or cost of whole-genome sequencing (WGS) library preparation. stLFR represents an easily automatable solution that enables high-quality sequencing, phasing, SV detection, scaffolding, cost-effective diploid de novo genome assembly, and other long DNA sequencing applications.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento Completo do Genoma/métodos , Análise Custo-Benefício , Diploide , Biblioteca Gênica , Genoma Humano , Genômica , Haplótipos/genética , Sequenciamento de Nucleotídeos em Larga Escala/economia , Humanos , Sequenciamento Completo do Genoma/economia
15.
Small ; 18(39): e2203525, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36026562

RESUMO

Magnesium ion batteries (MIBs) have attracted much attention due to their low cost and high safety properties. However, the intense charge repulsion effect and sluggish diffusion dynamics of Mg2+ ions result in unsatisfactory electrochemical performance of conventional cathode materials in MIBs. This work reports water-lubricated aluminum vanadate (HAlVO) as high-performance cathode material for Mg2+ ions storage and investigates the capacity fade mechanism of water-free aluminum vanadate (AlVO). The charge density difference based on density functional theory calculation is performed to analyze the charge transfer process of water-lubricated/free aluminum vanadates (HAlVO/AlVO). The different charge transfer phenomena of two materials and the charge shielding effect of water molecule in HAlVO are revealed. Moreover, the single-phase structural evolution process and the Mg2+ ions storage mechanism of HAlVO are further investigated deeply by different in situ and ex situ characterization methods. This work proves that HAlVO is a potential candidate cathode material to satisfy the high-performance reversible Mg2+ ions storage, and the water-lubricated method is an effective strategy to improve the electrochemical performance of vanadium oxides cathode.

16.
Plant Biotechnol J ; 20(7): 1387-1401, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35560858

RESUMO

Amylose content is a crucial physicochemical property responsible for the eating and cooking quality of rice (Oryza sativa L.) grain and is mainly controlled by the Waxy (Wx) gene. Previous studies have identified several Dull genes that modulate the expression of the Wxb allele in japonica rice by affecting the splicing efficiency of the Wxb pre-mRNA. Here, we uncover dual roles for a novel Dull gene in pre-mRNA splicing and microRNA processing. We isolated the dull mutant, du13, with a dull endosperm and low amylose content. Map-based cloning showed that Du13 encodes a C2 H2 zinc-finger protein. Du13 coordinates with the nuclear cap-binding complex to regulate the splicing of Wxb transcripts in rice endosperm. Moreover, Du13 also regulates alternative splicing of other protein-coding transcripts and affects the biogenesis of a subset of microRNAs. Our results reveal an evolutionarily conserved link between pre-mRNA splicing and microRNA biogenesis in rice endosperm. Our findings also provide new insights into the functions of Dull genes in rice and expand our knowledge of microRNA biogenesis in monocots.


Assuntos
MicroRNAs , Oryza , Sintase do Amido , Amilose/metabolismo , Endosperma/genética , Endosperma/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Sintase do Amido/genética , Ceras/metabolismo , Zinco/metabolismo
17.
Plant Biotechnol J ; 20(3): 437-453, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34655511

RESUMO

Starch accounts for over 80% of the total dry weight in cereal endosperm and determines the kernel texture and nutritional quality. Amyloplasts, terminally differentiated plastids, are responsible for starch biosynthesis and storage. We screened a series of rice mutants with floury endosperm to clarify the mechanism underlying amyloplast development and starch synthesis. We identified the floury endosperm19 (flo19) mutant which shows opaque of the interior endosperm. Abnormal compound starch grains (SGs) were present in the endosperm cells of the mutant. Molecular cloning revealed that the FLO19 allele encodes a plastid-localized pyruvate dehydrogenase complex E1 component subunit α1 (ptPDC-E1-α1) that is expressed in all rice tissues. In vivo enzyme assays demonstrated that the flo19 mutant showed decreased activity of the plastidic pyruvate dehydrogenase complex. In addition, the amounts of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) were much lower in the developing flo19 mutant endosperm, suggesting that FLO19 participates in fatty acid supply for galactolipid biosynthesis in amyloplasts. FLO19 overexpression significantly increased seed size and weight, but did not affect other important agronomic traits, such as panicle length, tiller number and seed setting rate. An analysis of single nucleotide polymorphism data from a panel of rice accessions identified that the pFLO19L haplotype was positively associated with grain length, implying a potential application in rice breeding. In summary, our study demonstrates that FLO19 is involved in galactolipid biosynthesis which is essential for amyloplast development and starch biosynthesis in rice.


Assuntos
Oryza , Grão Comestível , Endosperma/metabolismo , Galactolipídeos , Regulação da Expressão Gênica de Plantas , Mutação/genética , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plastídeos/metabolismo , Complexo Piruvato Desidrogenase , Amido/metabolismo
18.
Int J Mol Sci ; 23(21)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36362297

RESUMO

Subcellular mRNA localization is an evolutionarily conserved mechanism to spatially and temporally drive local translation and, in turn, protein targeting. Hence, this mechanism achieves precise control of gene expression and establishes functional and structural networks during cell growth and development as well as during stimuli response. Since its discovery in ascidian eggs, mRNA localization has been extensively studied in animal and yeast cells. Although our knowledge of subcellular mRNA localization in plant cells lags considerably behind other biological systems, mRNA localization to the endoplasmic reticulum (ER) has also been well established since its discovery in cereal endosperm cells in the early 1990s. Storage protein mRNA targeting to distinct subdomains of the ER determines efficient accumulation of the corresponding proteins in different endosomal storage sites and, in turn, underlies storage organelle biogenesis in cereal grains. The targeting process requires the presence of RNA localization elements, also called zipcodes, and specific RNA-binding proteins that recognize and bind these zipcodes and recruit other factors to mediate active transport. Here, we review the current knowledge of the mechanisms and functions of mRNA localization to the ER in plant cells and address directions for future research.


Assuntos
Endosperma , Células Vegetais , Animais , Endosperma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células Vegetais/metabolismo , Retículo Endoplasmático/metabolismo , Transporte Proteico , Grão Comestível/metabolismo
19.
Circulation ; 142(13): 1261-1278, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32686471

RESUMO

BACKGROUND: Atrial fibrillation (AF) is the most common heart rhythm disorder in adults and a major cause of stroke. Unfortunately, current treatments of AF are suboptimal because they are not targeted to the molecular mechanisms underlying AF. Using a highly novel gene therapy approach in a canine, rapid atrial pacing model of AF, we demonstrate that NADPH oxidase 2 (NOX2) generated oxidative injury causes upregulation of a constitutively active form of acetylcholine-dependent K+ current (IKACh), called IKH; this is an important mechanism underlying not only the genesis, but also the perpetuation of electric remodeling in the intact, fibrillating atrium. METHODS: To understand the mechanism by which oxidative injury promotes the genesis and maintenance of AF, we performed targeted injection of NOX2 short hairpin RNA (followed by electroporation to facilitate gene delivery) in atria of healthy dogs followed by rapid atrial pacing. We used in vivo high-density electric mapping, isolation of atrial myocytes, whole-cell patch clamping, in vitro tachypacing of atrial myocytes, lucigenin chemiluminescence assay, immunoblotting, real-time polymerase chain reaction, immunohistochemistry, and Masson trichrome staining. RESULTS: First, we demonstrate that generation of oxidative injury in atrial myocytes is a frequency-dependent process, with rapid pacing in canine atrial myocytes inducing oxidative injury through the induction of NOX2 and the generation of mitochondrial reactive oxygen species. We show that oxidative injury likely contributes to electric remodeling in AF by upregulating IKACh by a mechanism involving frequency-dependent activation of PKCε (protein kinase C epsilon). The time to onset of nonsustained AF increased by >5-fold in NOX2 short hairpin RNA-treated dogs. Furthermore, animals treated with NOX2 short hairpin RNA did not develop sustained AF for up to 12 weeks. The electrophysiological mechanism underlying AF prevention was prolongation of atrial effective refractory periods, at least in part attributable to the attenuation of IKACh. Attenuated membrane translocation of PKCε appeared to be a likely molecular mechanism underlying this beneficial electrophysiological remodeling. CONCLUSIONS: NOX2 oxidative injury (1) underlies the onset, and the maintenance of electric remodeling in AF, as well, and (2) can be successfully prevented with a novel, gene-based approach. Future optimization of this approach may lead to a novel, mechanism-guided therapy for AF.


Assuntos
Fibrilação Atrial , Remodelamento Atrial , Regulação Enzimológica da Expressão Gênica , Terapia Genética , NADPH Oxidase 2 , RNA Interferente Pequeno , Animais , Fibrilação Atrial/enzimologia , Fibrilação Atrial/genética , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/terapia , Cães , Átrios do Coração/enzimologia , Átrios do Coração/fisiopatologia , NADPH Oxidase 2/biossíntese , NADPH Oxidase 2/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
20.
Nanotechnology ; 32(31)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33906187

RESUMO

Rechargeable aqueous zinc-ion batteries (AZIBs) have garnered widespread attention as a new large-scale energy storage candidate owing to their low cost and high theoretical capacity. Because of the unique divalent state of Zn2+and the existence of a strong electrostatic repulsion phenomenon, researchers are currently focusing on how to prepare high-performance cathode materials. In this study, we synthesized aluminum vanadate (AlV3O9) as a cathode material for AZIBs using a solvothermal method. Al3+acted as a pillar in the resultant structure and stabilized it. Furthermore, this large interlayer spacing enhanced the ion diffusion coefficient and accelerated the ion transport process. Because of these advantages, the AlV3O9(AVO) cathode exhibited excellent electrochemical performance, including a high capacity of 421.0 mA h g-1at 0.1 A g-1and a stable rate capability of 348.2 mA h g-1at 1 A g-1. Moreover, it exhibited a specific capacity of 202 mA h g-1even at a high current density of 3 A g-1(the capacity retention rate reached 84.38% after 1600 cycles). The prepared ZIBs presented a high power density of 366.6 W kg-1at an energy density of 286 W h kg-1. These extraordinary results indicate the great application potential of AVO as a cathode material for AZIBs.

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