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1.
Gene ; 758: 144962, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32687946

RESUMO

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by the autoimmune inflammation, demyelination, and neurodegeneration. This complex disease develops in genetically predisposed individuals under adverse environmental factors. To date, a large number of MS-associated polymorphic loci of the nuclear genome have been identified; however, their total variability can explain only about 48% of the observed inheritance of MS. Polymorphic variants of the mitochondrial genome and interactions of mitochondrial and nuclear genes (mitonuclear interactions) may be the possible sources of the "missing heritability". We analyzed the association with MS of 10 mitochondrial DNA polymorphisms (m.1719, m.4216, m.4580, m.4917, m.7028, m.9055, m.10398, m.12308, m.13368, m.13708) in DNA of 540 MS patients and 406 healthy individuals. The allele m.9055*G was the only mitochondrial variant associated with MS (Pf = 0.027). To evaluate interactions of mitochondrial and nuclear genomes, we searched for biallelic combinations containing one of 10 mitochondrial variants and one of 35 variants of immune-related nuclear genes. Carriership of mitochondrial variants m.4216, m.4580, or m.13708 in biallelic combinations with variants of nuclear genes IL7R, CLEC16A, CD6, CD86 or PVT1 was associated with MS (Pf = 0.0036-0.00030). We identified epistatic interaction between components of a combination (m.13708*A + PVT1 rs4410871*T). The existence of epistatic biallelic combination can reflect the genuine mitonuclear epistasis.


Assuntos
Núcleo Celular/genética , DNA Mitocondrial/genética , Predisposição Genética para Doença/genética , Genoma Mitocondrial/genética , Esclerose Múltipla/genética , Adulto , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Antígeno B7-2/genética , Feminino , Estudos de Associação Genética , Humanos , Subunidade alfa de Receptor de Interleucina-7/genética , Lectinas Tipo C/genética , Masculino , Mitocôndrias/genética , Proteínas de Transporte de Monossacarídeos/genética , Polimorfismo de Nucleotídeo Único/genética , RNA Longo não Codificante/genética
2.
PLoS One ; 15(5): e0232846, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32380514

RESUMO

The structure of lactose permease, stabilized in a periplasmic open conformation by two Gly to Trp replacements (LacYww) and complexed with a nanobody directed against this conformation, provides the highest resolution structure of the symporter. The nanobody binds in a different manner than two other nanobodies made against the same mutant, which also bind to the same general region on the periplasmic side. This region of the protein may represent an immune hotspot. The CDR3 loop of the nanobody is held by hydrogen bonds in a conformation that partially blocks access to the substrate-binding site. As a result, kon and koff for galactoside binding to either LacY or the double mutant complexed with the nanobody are lower than for the other two LacY/nanobody complexes though the Kd values are similar, reflecting the fact that the nanobodies rigidify structures along the pathway. While the wild-type LacY/nanobody complex clearly stabilizes a similar 'extracellular open' conformation in solution, judged by binding kinetics, the complex with wild-type LacY did not yet crystallize, suggesting the nanobody does not bind strongly enough to shift the equilibrium to stabilize a periplasmic side-open conformation suitable for crystallization. However, the similarity of the galactoside binding kinetics for the nanobody-bound complexes with wild type LacY and with LacYWW indicates that they have similar structures, showing that the reported co-structures reliably show nanobody interactions with LacY.


Assuntos
Proteínas de Escherichia coli/química , Proteínas de Transporte de Monossacarídeos/química , Anticorpos de Domínio Único/química , Simportadores/química , Substituição de Aminoácidos , Reações Antígeno-Anticorpo , Sítios de Ligação , Cristalografia por Raios X , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/imunologia , Galactose/metabolismo , Glicina/química , Ligação de Hidrogênio , Cinética , Modelos Moleculares , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/imunologia , Mutação de Sentido Incorreto , Mutação Puntual , Ligação Proteica , Conformação Proteica , Estabilidade Proteica , Anticorpos de Domínio Único/imunologia , Relação Estrutura-Atividade , Simportadores/genética , Simportadores/imunologia , Tiogalactosídeos/química , Triptofano/química
3.
PLoS One ; 15(5): e0233719, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469960

RESUMO

The formation of a tube-like structure is a basic step in the making of functional hearts in vertebrates and invertebrates and therefore, its understanding provides important information on heart development and function. In Drosophila, the cardiac tube originates from two bilateral rows of dorsally migrating cells. On meeting at the dorsal midline, coordinated changes in cell shape and adhesive properties transform the two sheets of cells into a linear tube. ECM and transmembrane proteins linked to the cytoskeleton play an important role during these dynamic processes. Here we characterize the requirement of Cbl-Associated Protein (CAP) in Drosophila heart formation. In embryos, CAP is expressed in late migrating cardioblasts and is located preferentially at their luminal and abluminal periphery. CAP mutations result in irregular cardioblast alignment and imprecisely controlled cardioblast numbers. Furthermore, CAP mutant embryos show a strongly reduced heart lumen and an aberrant shape of lumen forming cardioblasts. Analysis of double heterozygous animals reveals a genetic interaction of CAP with Integrin- and Talin-encoding genes. In post-embryonic stages, CAP closely colocalizes with Integrin near Z-bands and at cell-cell contact sites. CAP mutants exhibit a reduced contractility in larval hearts and show a locally disrupted morphology, which correlates with a reduced pumping efficiency. Our observations imply a function of CAP in linking Integrin signaling with the actin cytoskeleton. As a modulator of the cytoskeleton, CAP is involved in the establishment of proper cell shapes during cardioblast alignment and cardiac lumen formation in the Drosophila embryo. Furthermore, CAP is required for correct heart function throughout development.


Assuntos
Movimento Celular , Proteínas de Drosophila/metabolismo , Embrião não Mamífero/embriologia , Coração/embriologia , Proteínas de Transporte de Monossacarídeos/metabolismo , Contração Miocárdica , Organogênese , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteínas de Transporte de Monossacarídeos/genética , Mutação
4.
Nat Chem Biol ; 16(4): 469-478, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32152546

RESUMO

Solute carriers (SLCs) are the largest family of transmembrane transporters in humans and are major determinants of cellular metabolism. Several SLCs have been shown to be required for the uptake of chemical compounds into cellular systems, but systematic surveys of transporter-drug relationships in human cells are currently lacking. We performed a series of genetic screens in a haploid human cell line against 60 cytotoxic compounds representative of the chemical space populated by approved drugs. By using an SLC-focused CRISPR-Cas9 library, we identified transporters whose absence induced resistance to the drugs tested. This included dependencies involving the transporters SLC11A2/SLC16A1 for artemisinin derivatives and SLC35A2/SLC38A5 for cisplatin. The functional dependence on SLCs observed for a significant proportion of the screened compounds suggests a widespread role for SLCs in the uptake and cellular activity of cytotoxic drugs and provides an experimentally validated set of SLC-drug associations for a number of clinically relevant compounds.


Assuntos
Resistência a Medicamentos/genética , Proteínas Carreadoras de Solutos/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Antineoplásicos , Fenômenos Bioquímicos , Transporte Biológico/genética , Transporte Biológico/fisiologia , Sistemas CRISPR-Cas , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Resistência a Medicamentos/fisiologia , Testes Genéticos , Humanos , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/metabolismo , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Transporte Proteico/fisiologia , Proteínas Carreadoras de Solutos/fisiologia , Simportadores/genética , Simportadores/metabolismo
5.
PLoS Genet ; 15(11): e1008375, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738765

RESUMO

DNA variants that alter gene expression contribute to variation in many phenotypic traits. In particular, trans-acting variants, which are often located on different chromosomes from the genes they affect, are an important source of heritable gene expression variation. However, our knowledge about the identity and mechanism of causal trans-acting variants remains limited. Here, we developed a fine-mapping strategy called CRISPR-Swap and dissected three expression quantitative trait locus (eQTL) hotspots known to alter the expression of numerous genes in trans in the yeast Saccharomyces cerevisiae. Causal variants were identified by engineering recombinant alleles and quantifying the effects of these alleles on the expression of a green fluorescent protein-tagged gene affected by the given locus in trans. We validated the effect of each variant on the expression of multiple genes by RNA-sequencing. The three variants differed in their molecular mechanism, the type of genes they reside in, and their distribution in natural populations. While a missense leucine-to-serine variant at position 63 in the transcription factor Oaf1 (L63S) was almost exclusively present in the reference laboratory strain, the two other variants were frequent among S. cerevisiae isolates. A causal missense variant in the glucose receptor Rgt2 (V539I) occurred at a poorly conserved amino acid residue and its effect was strongly dependent on the concentration of glucose in the culture medium. A noncoding variant in the conserved fatty acid regulated (FAR) element of the OLE1 promoter influenced the expression of the fatty acid desaturase Ole1 in cis and, by modulating the level of this essential enzyme, other genes in trans. The OAF1 and OLE1 variants showed a non-additive genetic interaction, and affected cellular lipid metabolism. These results demonstrate that the molecular basis of trans-regulatory variation is diverse, highlighting the challenges in predicting which natural genetic variants affect gene expression.


Assuntos
Proteínas de Ligação a DNA/genética , Evolução Molecular , Sequências Reguladoras de Ácido Nucleico/genética , Proteínas de Saccharomyces cerevisiae/genética , Estearoil-CoA Dessaturase/genética , Fatores de Transcrição/genética , Sistemas CRISPR-Cas/genética , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Regulação Fúngica da Expressão Gênica/genética , Proteínas de Fluorescência Verde/genética , Metabolismo dos Lipídeos/genética , Proteínas de Transporte de Monossacarídeos/genética , Mutação de Sentido Incorreto/genética , Fenótipo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
6.
BMC Plant Biol ; 19(1): 499, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31726992

RESUMO

BACKGROUND: SWEETs (Sugar Will Eventually be Exported transporters) function as sugar efflux transporters that perform diverse physiological functions, including phloem loading, nectar secretion, seed filling, and pathogen nutrition. The SWEET gene family has been identified and characterized in a number of plant species, but little is known about in Litchi chinensis, which is an important evergreen fruit crop. RESULTS: In this study, 16 LcSWEET genes were identified and nominated according to its homologous genes in Arabidopsis and grapevine. Multiple sequence alignment showed that the 7 alpha-helical transmembrane domains (7-TMs) were basically conserved in LcSWEETs. The LcSWEETs were divided into four clades (Clade I to Clade IV) by phylogenetic tree analysis. A total of 8 predicted motifs were detected in the litchi LcSWEET genes. The 16 LcSWEET genes were unevenly distributed in 9 chromosomes and there was one pairs of segmental duplicated events by synteny analysis. The expression patterns of the 16 LcSWEET genes showed higher expression levels in reproductive organs. The temporal and spatial expression patterns of LcSWEET2a and LcSWEET3b indicated they play central roles during early seed development. CONCLUSIONS: The litchi genome contained 16 SWEET genes, and most of the genes were expressed in different tissues. Gene expression suggested that LcSWEETs played important roles in the growth and development of litchi fruits. Genes that regulate early seed development were preliminarily identified. This work provides a comprehensive understanding of the SWEET gene family in litchi, laying a strong foundation for further functional studies of LcSWEET genes and improvement of litchi fruits.


Assuntos
Litchi/genética , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Plantas/genética , Sementes/crescimento & desenvolvimento , Cromossomos de Plantas , Sequência Conservada , DNA de Plantas , Perfilação da Expressão Gênica , Genes de Plantas , Filogenia , Sementes/genética , Alinhamento de Sequência , Sintenia
7.
Plant Physiol Biochem ; 145: 107-113, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31677541

RESUMO

Hexose transporters play many important roles in plant development. However, the role of hexose transporter in secondary cell wall growth has not been reported before. Here, we report that the hexose transporter gene CsHT3 is mainly expressed in cells with secondary cell walls in cucumber. Spatiotemporal expression analysis revealed that the transcript of CsHT3 mainly accumulates in the stem, petiole, tendril, and peduncle, all of which contain high cellulose levels. Immunolocalization results show that CsHT3 is localized at the sclereids in young peduncles, shifts to the phloem fiber cells during peduncle development, and then shifts again to the companion cells when the development of secondary cell walls is almost completed. Carboxyfluoresce unloading experiment indicated that carbohydrate unloading in the phloem follows an apoplastic pathway. Overexpression of CsHT3 in cucumber plant can improve the cellulose content and cell wall thickness of phloem fiber cells in the peduncle. The expression of cellulose synthase genes were increased in the CsHT3 overexpression plants. These results indicated that CsHT3 may play an important role in cellulose synthesis through promoting the expression of cellulose synthase genes.


Assuntos
Cucumis sativus , Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Transporte de Monossacarídeos , Proteínas de Plantas , Parede Celular , Celulose/genética , Celulose/metabolismo , Cucumis sativus/genética , Cucumis sativus/metabolismo , Frutas/química , Frutas/genética , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Floema , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
8.
Genes (Basel) ; 10(10)2019 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-31591342

RESUMO

In maize seed germination, the endosperm and the scutellum nourish the embryo axis. Here, we examined the mRNA relative amount of the SWEET protein family, which could be involved in sugar transport during germination since high [14-C]-glucose and mainly [14-C]-sucrose diffusional uptake were found in embryo tissues. We identified high levels of transcripts for SWEETs in the three phases of the germination process: ZmSWEET4c, ZmSWEET6b, ZmSWEET11, ZmSWEET13a, ZmSWEET13b, ZmSWEET14b and ZmSWEET15a, except at 0 h of imbibition where the abundance of each ZmSWEET was low. Despite the major sucrose (Suc) biosynthesis capacity of the scutellum and the high level of transcripts of the Suc symporter SUT1, Suc was not found to be accumulated; furthermore, in the embryo axis, Suc did not decrease but hexoses increased, suggesting an efficient Suc efflux from the scutellum to nourish the embryo axis. The influx of Glc into the scutellum could be mediated by SWEET4c to take up the large amount of transported sugars due to the late hydrolysis of starch. In addition, sugars regulated the mRNA amount of SWEETs at the embryo axis. These results suggest an important role for SWEETs in transporting Suc and hexoses between the scutellum and the embryo axis, and differences in SWEET transcripts between both tissues might occur because of the different sugar requirements and metabolism.


Assuntos
Proteínas de Transporte de Monossacarídeos/genética , Zea mays/embriologia , Zea mays/genética , Transporte Biológico/genética , Metabolismo dos Carboidratos/genética , Endosperma/genética , Regulação da Expressão Gênica de Plantas/genética , Glucose/metabolismo , Hexoses/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas de Plantas/genética , Sementes/embriologia , Amido/metabolismo , Sacarose/metabolismo
9.
Nutrients ; 11(10)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581549

RESUMO

Diseases involving inflammation and oxidative stress can be exacerbated by high blood glucose levels. Due to tight metabolic regulation, safely reducing blood glucose can prove difficult. The ketogenic diet (KD) reduces absolute glucose and insulin, while increasing fatty acid oxidation, ketogenesis, and circulating levels of ß-hydroxybutyrate (ßHB), acetoacetate (AcAc), and acetone. Compliance to KD can be difficult, so alternative therapies that help reduce glucose levels are needed. Exogenous ketones provide an alternative method to elevate blood ketone levels without strict dietary requirements. In this study, we tested the changes in blood glucose and ketone (ßHB) levels in response to acute, sub-chronic, and chronic administration of various ketogenic compounds in either a post-exercise or rested state. WAG/Rij (WR) rats, a rodent model of human absence epilepsy, GLUT1 deficiency syndrome mice (GLUT1D), and wild type Sprague Dawley rats (SPD) were assessed. Non-pathological animals were also assessed across different age ranges. Experimental groups included KD, standard diet (SD) supplemented with water (Control, C) or with exogenous ketones: 1, 3-butanediol (BD), ßHB mineral salt (KS), KS with medium chain triglyceride/MCT (KSMCT), BD acetoacetate diester (KE), KE with MCT (KEMCT), and KE with KS (KEKS). In rested WR rats, the KE, KS, KSMCT groups had lower blood glucose level after 1 h of treatment, and in KE and KSMCT groups after 24 h. After exercise, the KE, KSMCT, KEKS, and KEMCT groups had lowered glucose levels after 1 h, and in the KEKS and KEMCT groups after 7 days, compared to control. In GLUT1D mice without exercise, only KE resulted in significantly lower glucose levels at week 2 and week 6 during a 10 weeks long chronic feeding study. In 4-month and 1-year-old SPD rats in the post-exercise trials, blood glucose was significantly lower in KD and KE, and in KEMCT groups, respectively. After seven days, the KSMCT group had the most significantly reduced blood glucose levels, compared to control. These results indicate that exogenous ketones were efficacious in reducing blood glucose levels within and outside the context of exercise in various rodent models of different ages, with and without pathology.


Assuntos
Ácido 3-Hidroxibutírico/farmacologia , Acetoacetatos/farmacologia , Glicemia/efeitos dos fármacos , Butileno Glicóis/farmacologia , Erros Inatos do Metabolismo dos Carboidratos/terapia , Dieta Cetogênica , Suplementos Nutricionais , Epilepsia Tipo Ausência/terapia , Proteínas de Transporte de Monossacarídeos/deficiência , Animais , Biomarcadores , Glicemia/metabolismo , Erros Inatos do Metabolismo dos Carboidratos/sangue , Erros Inatos do Metabolismo dos Carboidratos/genética , Erros Inatos do Metabolismo dos Carboidratos/fisiopatologia , Modelos Animais de Doenças , Regulação para Baixo , Epilepsia Tipo Ausência/sangue , Epilepsia Tipo Ausência/genética , Epilepsia Tipo Ausência/fisiopatologia , Transportador de Glucose Tipo 1/deficiência , Transportador de Glucose Tipo 1/genética , Masculino , Camundongos Knockout , Proteínas de Transporte de Monossacarídeos/sangue , Proteínas de Transporte de Monossacarídeos/genética , Esforço Físico , Ratos Sprague-Dawley , Descanso , Fatores de Tempo
10.
PLoS One ; 14(9): e0223173, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31568488

RESUMO

Sugar transporters play a crucial role for plant productivity, as they coordinate sugar fluxes from source leaf towards sink organs (seed, fruit, root) and regulate the supply of carbon resources towards the microorganisms of the rhizosphere (bacteria and fungi). Thus, sugar fluxes mediated by SUT (sucrose transporters), MST (monosaccharide transporters) and SWEET (sugar will eventually be exported transporters) families are key determinants of crop yield and shape the microbial communities living in the soil. In this work, we performed a systematic search for sugar transporters in Fabaceae genomes, focusing on model and agronomical plants. Here, we update the inventory of sugar transporter families mining the latest version of the Medicago truncatula genome and identify for the first time SUT MST and SWEET families of the agricultural crop Pisum sativum. The sugar transporter families of these Fabaceae species comprise respectively 7 MtSUT 7 PsSUT, 72 MtMST 59 PsMST and 26 MtSWEET 22 PsSWEET. Our comprehensive phylogenetic analysis sets a milestone for the scientific community, as we propose a new and simple nomenclature to correctly name SUT MST and SWEET families. Then, we searched for transcriptomic data available for our gene repertoire. We show that several clusters of homologous genes are co-expressed in different organs, suggesting that orthologous sugar transporters may have a conserved function. We focused our analysis on gene candidates that may be involved in remobilizing resources during flowering, grain filling and in allocating carbon towards roots colonized by arbuscular mycorrhizal fungi and Rhizobia. Our findings open new perspectives for agroecological applications in legume crops, as for instance improving the yield and quality of seed productions and promoting the use of symbiotic microorganisms.


Assuntos
Regulação da Expressão Gênica de Plantas , Genoma de Planta , Medicago truncatula/genética , Proteínas de Transporte de Monossacarídeos/genética , Ervilhas/genética , Proteínas de Plantas/genética , Transporte Biológico , Produtos Agrícolas , Ontologia Genética , Humanos , Medicago truncatula/classificação , Medicago truncatula/metabolismo , Anotação de Sequência Molecular , Proteínas de Transporte de Monossacarídeos/classificação , Proteínas de Transporte de Monossacarídeos/metabolismo , Ervilhas/classificação , Ervilhas/metabolismo , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Rizosfera , Terminologia como Assunto
11.
Genes (Basel) ; 10(9)2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31540414

RESUMO

The SWEET family, which includes transcripts of a cohort of plant hexose and sucrose transporters, is considered key to improving crop stress tolerance and yield through its role in manipulating the carbohydrate partitioning process. The functions and regulatory roles of this gene family are variable among different species; thus, to determine these roles, more species-specific information is needed. Brassica rapa displays complicated regulation after a whole-genome triplication (WGT) event, which provides enormous advantages for use in genetic studies, thus it is an ideal model for exploring the functional and regulatory roles of SWEETs from a genetic perspective. In this study, the results of a homology search and phylogenetic relationship analysis revealed the evolutionary footprint of SWEETs among different plant taxa, which showed that plant SWEETs may have originated from Clade II and then expanded from vascular plants. The amino acid sequence characteristics and an analysis of the exon-intron structure of BrSWEETs duplicates clarified that SWEETs retention occurred after a WGT event in B. rapa. An analysis of the transcriptional levels of BrSWEETs in different tissues identified the expression differences among duplicated co-orthologs. In addition, qRT-PCR indicated that the BrSWEETs' co-orthologs were varied in their stress responses. This study greatly enriches our knowledge of SWEETs in the B. rapa species, which will contribute to future studies on the Brassica-specific regulatory pathways and to creating genetic innovations.


Assuntos
Brassica rapa/genética , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Plantas/genética , Triploidia , Evolução Molecular , Genoma de Planta , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas de Plantas/metabolismo , Transcriptoma
12.
Plant Physiol ; 181(3): 1328-1343, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31540949

RESUMO

Biotrophic pathogens, such as wheat rust fungi, survive on nutrients derived from host cells. Sugar appears to be the major carbon source transferred from host cells to various fungal pathogens; however, the molecular mechanism by which host sugar transporters are manipulated by fungal pathogens for nutrient uptake is poorly understood. TaSTP6, a sugar transporter protein in wheat (Triticum aestivum), was previously shown to exhibit enhanced expression in leaves upon infection by Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust. In this study, we found that Pst infection caused increased accumulation of abscisic acid (ABA) and that application of exogenous ABA significantly enhanced TaSTP6 expression. Moreover, knockdown of TaSTP6 expression by barley stripe mosaic virus-induced gene silencing reduced wheat susceptibility to the Pst pathotype CYR31, suggesting that TaSTP6 expression upregulation contributes to Pst host sugar acquisition. Consistent with this, TaSTP6 overexpression in Arabidopsis (Arabidopsis thaliana) promoted plant susceptibility to powdery mildew and led to increased Glc accumulation in the leaves. Functional complementation assays in Saccharomyces cerevisiae showed that TaSTP6 has broad substrate specificity, indicating that TaSTP6 is an active sugar transporter. Subcellular localization analysis indicated that TaSTP6 localizes to the plasma membrane. Yeast two-hybrid and bimolecular fluorescence complementation experiments revealed that TaSTP6 undergoes oligomerization. Taken together, our results suggest that Pst stimulates ABA biosynthesis in host cells and thereby upregulates TaSTP6 expression, which increases sugar supply and promotes fungal infection.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Doenças das Plantas/imunologia , Reguladores de Crescimento de Planta/metabolismo , Açúcares/metabolismo , Triticum/genética , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/fisiologia , Ascomicetos/fisiologia , Basidiomycota/fisiologia , Suscetibilidade a Doenças , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Interações Hospedeiro-Patógeno , Proteínas de Transporte de Monossacarídeos/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triticum/imunologia , Triticum/fisiologia
13.
Nat Commun ; 10(1): 3657, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31413260

RESUMO

We lack an understanding of how the full range of genetic variants that occur in individuals can interact. To address this shortcoming, here we combine diverse mutations between genes in a model regulatory network, the galactose (GAL) switch of budding yeast. The effects of thousands of pairs of mutations fall into a limited number of phenotypic classes. While these effects are mostly predictable using simple rules that capture the 'stereotypical' genetic interactions of the network, some double mutants have unexpected outcomes including constituting alternative functional switches. Each of these 'harmonious' genetic combinations exhibits altered dependency on other regulatory genes. These cases illustrate how both pairwise and higher epistasis determines gene essentiality and how combinations of mutations rewire regulatory networks. Together, our results provide an overview of how broad spectra of mutations interact, how these interactions can be predicted, and how diverse genetic solutions can achieve 'wild-type' phenotypic behavior.


Assuntos
Proteínas de Ligação a DNA/genética , Galactose/metabolismo , Proteínas Repressoras/genética , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/genética , Epistasia Genética , Galactoquinase/genética , Regulação Fúngica da Expressão Gênica , Redes Reguladoras de Genes , Proteínas de Transporte de Monossacarídeos/genética , Mutação , Saccharomyces cerevisiae/genética , Biologia de Sistemas , Transativadores/genética
14.
Int J Mol Sci ; 20(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426432

RESUMO

Sugar transporters of the SWEET family mediate cross membrane movement of mono- and disaccharides and play vital roles in diverse physiological and pathophysiological processes, including sink-source relationship, pathogen responses, reproductive growth, and development. However, it remains to be determined how these transporters function in non-module plants of agricultural significance, given the evolutionarily diverse traits. In this study, we combined transcriptome analysis, rapid amplification of cDNA ends-cloning (RACE-cloning), expression profiling, and heterologous functional assay to identify SWEET genes that may have potential roles during flower opening and sexual reproduction in Jasminum sambac . During the anthesis, the floral organs of J. sambac express seven SWEET homologous genes from all four clades of the family. JsSWEET9 and 2 are significantly upregulated when flowers are fully opened, up to 6- and 3-fold compared to unopened buds, respectively. The other transporters, JsSWEET1, 5, 10, and 17 are also accumulated slightly at stage associated with fragrance release, whereas only the vacuole transporter JsSWEET16 showed small decrease in transcript level after anthesis. The JsSWEET5, a clade II member, is capable to complement yeast cell uptake on most tested sugar substrates with a preference for hexoses, while the clade I transporter JsSWEET1 mediates merely galactose import when expressed in yeast. Our results provide first evidence for further investigation on sugar transport and allocation during flowering and reproductive processes in J. sambac.


Assuntos
Flores/genética , Jasminum/genética , Proteínas de Membrana Transportadoras/genética , Proteínas de Plantas/genética , Clonagem Molecular , Dissacarídeos/metabolismo , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Jasminum/crescimento & desenvolvimento , Jasminum/metabolismo , Proteínas de Membrana Transportadoras/análise , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Transporte de Monossacarídeos/análise , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Monossacarídeos/metabolismo , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo
15.
Ann Clin Transl Neurol ; 6(9): 1923-1932, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31464092

RESUMO

Proper development and function of the mammalian brain is critically dependent on a steady supply of its chief energy source, glucose. Such supply is mediated by the glucose transporter 1 (Glut1) protein. Paucity of the protein stemming from mutations in the associated SLC2A1 gene deprives the brain of glucose and triggers the infantile-onset neurodevelopmental disorder, Glut1 deficiency syndrome (Glut1 DS). Considering the monogenic nature of Glut1 DS, the disease is relatively straightforward to model and thus study. Accordingly, Glut1 DS serves as a convenient paradigm to investigate the more general cellular and molecular consequences of brain energy failure. Here, we review how Glut1 DS models have informed the biology of a prototypical brain energy failure syndrome, how these models are facilitating the development of promising new treatments for the human disease, and how important insights might emerge from the study of Glut1 DS to illuminate the myriad conditions involving the Glut1 protein.


Assuntos
Erros Inatos do Metabolismo dos Carboidratos/terapia , Dieta Cetogênica , Terapia Genética , Transportador de Glucose Tipo 1/genética , Proteínas de Transporte de Monossacarídeos/deficiência , Triglicerídeos/uso terapêutico , Encéfalo/metabolismo , Erros Inatos do Metabolismo dos Carboidratos/tratamento farmacológico , Erros Inatos do Metabolismo dos Carboidratos/genética , Humanos , Proteínas de Transporte de Monossacarídeos/genética , Mutação
16.
Hum Mutat ; 40(8): 1010-1012, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31374155

RESUMO

The congenital disorders of glycosylation are a diverse group of disorders, which present both common and unique challenges in the diagnosis of rare disorders. These disorders affect a variety of structures and processes in their synthesis. Studies by Himmelreich and by Ng and their coworkers are discussed as they exemplify the extremes of such challenges. These include ascertainment bias associated with the recognition of only extreme phenotypes, variant classification limited by the rarity of the observed variant, limitations in glycan methodology, and expression patterns that can change with time and tissue type. The continuing importance of functional studies to help sort out these challenges is highlighted.


Assuntos
Defeitos Congênitos da Glicosilação/genética , Proteínas de Transporte de Monossacarídeos/genética , Doenças Raras/genética , Predisposição Genética para Doença , Variação Genética , Humanos
18.
Int J Mol Sci ; 20(13)2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31261714

RESUMO

The regulation of sugar metabolism and partitioning plays an essential role for a plant's acclimation to its environment, with specific responses in autotrophic and heterotrophic organs. In this work, we analyzed the effects of high salinity on sugar partitioning and vascular anatomy within the floral stem. Stem sucrose and fructose content increased, while starch reduced, in contrast to the response observed in rosette leaves of the same plants. In the stem, the effects were associated with changes in the expression of SWEET and TMT2 genes encoding sugar transporters, SUSY1 encoding a sucrose synthase and several FRK encoding fructokinases. By contrast, the expression of SUC2, SWEET11 and SWEET12, encoding sugar transporters for phloem loading, remained unchanged in the stem. Both the anatomy of vascular tissues and the composition of xylem secondary cell walls were altered, suggesting that high salinity triggered major readjustments of sugar partitioning in this heterotrophic organ. There were changes in the composition of xylem cell walls, associated with the collapse and deformation of xylem vessels. The data are discussed regarding sugar partitioning and homeostasis of sugars in the vascular tissues of the stem.


Assuntos
Floema/metabolismo , Estresse Salino , Açúcares/metabolismo , Xilema/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/crescimento & desenvolvimento , Frutoquinases/genética , Frutoquinases/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Homeostase , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Floema/citologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Xilema/citologia
20.
Brain Dev ; 41(10): 854-861, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31326153

RESUMO

INTRODUCTION: The neurodevelopmental outcomes of young infants with hypoglycorrhachia that is comparable to glucose transporter 1 deficiency syndrome (GLUT1DS), i.e. cerebrospinal fluid (CSF) glucose ≤40 mg/dL and CSF lactate <2.2 mM without causes of secondary hypoglycorrhachia are unknown. This study investigated the developmental outcomes and possibility of GLUT1DS in infants with hypoglycorrhachia, or low CSF glucose concentration. MATERIAL AND METHODS: 1655 neurologically asymptomatic infants aged <4 months had CSF examinations for fever workup from 2006 to 2016. Among the infants with normal CSF cell counts and without isolated pathogens, there were hypoglycorrhachia group who had CSF glucose levels that were comparable to GLUT1DS, and age- and gender-matched non-hypoglycorrhachia group. Both groups were at a mean age of 5.9 ±â€¯2.4 years (ranged 1-10 years) at neurodevelopmental evaluation in 2017. Mutational analysis of solute-carrier-family 2, which facilitated the glucose transporter member 1 (SLC2A1) gene was performed. RESULTS: Among the 722 infants with normal CSF cell counts and without isolated pathogens, 30 (4.2%) had hypoglycorrhachia that was comparable to GLUT1DS. In the 25 infants with hypoglycorrhachia available for follow-up, 4 (16%) had abnormal outcomes, of which 3 (12%) had the history of mixed-type developmental delay before age 6 and 1 (4%) had type 1 diabetes mellitus. In the non-hypoglycorrhachia control group (n = 50), 2 patients (4%) showed abnormal outcomes, both with the history of pure speech delay. The hypoglycorrhachia group had a higher rate of the history of mixed-type of developmental delay than the control group (12% vs. 0%, P = 0.034). No SLC2A1 pathogenic variants were observed in the hypoglycorrhachia group. CONCLUSION: Hypoglycorrhachia may be a potential biomarker for neurodevelopmental delay instead of for GLUT1DS in neurologically asymptomatic young infants.


Assuntos
Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Glucose/líquido cefalorraquidiano , Erros Inatos do Metabolismo dos Carboidratos/genética , Erros Inatos do Metabolismo dos Carboidratos/fisiopatologia , Estudos de Casos e Controles , Pré-Escolar , Análise Mutacional de DNA , Feminino , Glucose/metabolismo , Humanos , Lactente , Recém-Nascido , Doenças do Recém-Nascido , Masculino , Proteínas de Transporte de Monossacarídeos/deficiência , Proteínas de Transporte de Monossacarídeos/genética , Transtornos do Neurodesenvolvimento/etiologia , Prevalência
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