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1.
J Med Internet Res ; 26: e56417, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38509662

RESUMO

BACKGROUND: Dysarthria is a common poststroke speech disorder affecting communication and psychological well-being. Traditional speech therapy is effective but often poses challenges in terms of accessibility and patient adherence. Emerging smartphone-based therapies may offer promising alternatives for the treatment of poststroke dysarthria. OBJECTIVE: This study aimed to assess the efficacy and feasibility of smartphone-based speech therapy for improving speech intelligibility in patients with acute and early subacute poststroke dysarthria. This study also explored the impact of the intervention on psychological well-being, user experience, and overall feasibility in a clinical setting. METHODS: Participants were divided into 2 groups for this randomized, evaluator-blinded trial. The intervention group used a smartphone-based speech therapy app for 1 hour per day, 5 days per week, for 4 weeks, with guideline-based standard stroke care. The control group received standard guideline-based stroke care and rehabilitation. Speech intelligibility, psychological well-being, quality of life, and user acceptance were assessed using repeated measures ANOVA. RESULTS: In this study, 40 patients with poststroke dysarthria were enrolled, 32 of whom completed the trial (16 in each group). The intervention group showed significant improvements in speech intelligibility compared with the control group. This was evidenced by improvements from baseline (F1,30=34.35; P<.001), between-group differences (F1,30=6.18; P=.02), and notable time-by-group interactions (F1,30=6.91; P=.01). Regarding secondary outcomes, the intervention led to improvements in the percentage of correct consonants over time (F1,30=5.57; P=.03). In addition, significant reductions were noted in the severity of dysarthria in the intervention group over time (F1,30=21.18; P<.001), with a pronounced group effect (F1,30=5.52; P=.03) and time-by-group interaction (F1,30=5.29; P=.03). Regarding quality of life, significant improvements were observed as measured by the EQ-5D-3L questionnaire (F1,30=13.25; P<.001) and EQ-VAS (F1,30=7.74; P=.009) over time. The adherence rate to the smartphone-based app was 64%, with over half of the participants completing all the sessions. The usability of the app was rated high (system usability score 80.78). In addition, the intervention group reported increased self-efficacy in using the app compared with the control group (F1,30=10.81; P=.003). CONCLUSIONS: The smartphone-based speech therapy app significantly improved speech intelligibility, articulation, and quality of life in patients with poststroke dysarthria. These findings indicate that smartphone-based speech therapy can be a useful assistant device in the management of poststroke dysarthria, particularly in the acute and early subacute stroke stages. TRIAL REGISTRATION: ClinicalTrials.gov NCT05146765; https://clinicaltrials.gov/ct2/show/NCT05146765.


Assuntos
Disartria , Estudos de Viabilidade , Smartphone , Fonoterapia , Acidente Vascular Cerebral , Humanos , Disartria/terapia , Disartria/etiologia , Fonoterapia/métodos , Masculino , Feminino , Projetos Piloto , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações , Idoso , Qualidade de Vida , Reabilitação do Acidente Vascular Cerebral/métodos , Aplicativos Móveis , Resultado do Tratamento
2.
Front Neurol ; 15: 1305297, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38356882

RESUMO

Background: Dysarthria is a motor speech disorder caused by various neurological diseases, particularly stroke. Individuals with post-stroke dysarthria experience impaired speech intelligibility, communication difficulties, and a reduced quality of life. However, studies on the treatment of post-stroke dysarthria are lacking. Digital speech therapy applications have the advantages of being personalized and easily accessible. However, evidence for their efficacy is not rigorous. Moreover, no studies have investigated both the acute to subacute, and chronic phases of stroke. This study aims to investigate the efficacy and feasibility of digital speech therapy applications in addressing these gaps in dysarthria treatment. Methods and design: This study is a multicenter, prospective, randomized, evaluator-blinded non-inferiority trial. We aim to recruit 76 participants with post-stroke dysarthria. Eligible participants will be stratified based on the onset period of stroke into acute to subacute, and chronic phases. Participants will be randomized in a 1:1 to receive either a personalized digital speech therapy application or conventional therapy with a workbook for 60 min daily, 5 days a week, for 4 weeks. The primary outcome is the improvement in speech intelligibility. This will be measured by how accurately independent listeners can transcribe passages read by the participants. Secondary outcomes, which include speech function, will be evaluated remotely by speech-language pathologists. This includes the maximum phonation time, oral diadochokinetic rate, and percentage of consonants correct. Participants' psychological well-being will also be assessed using self-report questionnaires, such as depressive symptoms (Patient Health Questionnaire-9) and quality of life (Quality of Life in the Dysarthric Speaker scale). The trial will also assess the feasibility, participant adherence, and usability of the application. Rigorous data collection and monitoring will be implemented to ensure patient safety. Conclusion: This trial aims to investigate the efficacy and feasibility of digital speech therapy applications for treating post-stroke dysarthria. The results could establish foundational evidence for future clinical trials with larger sample sizes. Clinical trial registration: Clinicaltrials.gov, identifier: NCT05865106.

3.
Pharmaceutics ; 13(2)2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33494293

RESUMO

A self-healing microencapsulation process involves mixing preformed porous microspheres in an aqueous solution containing the desired protein and converting them into closed-pore microspheres. Spongelike poly-d,l-lactide-co-glycolide (PLGA) microspheres are expected to be advantageous to protein loading through self-healing. This study aimed to identify and assess relevant critical parameters, using lysozyme as a model protein. Several parameters governed lysozyme loading. The pore characteristics (open-pore, closed-pore, and porosity) of the preformed microspheres substantially affected lysozyme loading efficiency. The type of surfactant present in the aqueous medium also influenced lysozyme loading efficiency. For instance, cetyltrimethylammonium bromide showing a superior wetting functionality increased the extent of lysozyme loading more than twice as compared to Tween 80. Dried preformed microspheres were commonly used before, but our study found that wet microspheres obtained at the end of the microsphere manufacturing process displayed significant advantages in lysozyme loading. Not only could an incubation time for hydrating the microspheres be shortened dramatically, but also a much more considerable amount of lysozyme was encapsulated. Interestingly, the degree of microsphere hydration determined the microstructure and morphology of closed-pore microspheres after self-healing. Understanding these critical process parameters would help tailor protein loading into spongelike PLGA microspheres in a bespoke manner.

4.
Artigo em Inglês | MEDLINE | ID: mdl-30072629

RESUMO

This study aimed to evaluate the relationship between various asbestos exposure routes and asbestos-related disorders (ARDs). The study population comprised 11,186 residents of a metropolitan city who lived near asbestos factories, shipyards, or in slate roof-dense areas. ARDs were determined from chest X-rays indicating lower lung fibrosis (LFF), pleural disease (PD), and lung masses (LMs). Of the subjects, 11.2%, 10.4%, 67.2% and 8.3% were exposed to asbestos via occupational, household, neighborhood, and slate roof routes, respectively. The odds ratio (OR) of PD from household exposure (i.e., living with asbestos-producing workers) was 1.9 (95% confidence interval: 0.9⁻4.2), and those of LLF and PD from neighborhood exposure, or residing near asbestos factories) for <19 or >20 years, or near a mine, were 4.1 (2.8⁻5.8) and 4.8 (3.4⁻6.7), 8.3 (5.5⁻12.3) and 8.0 (5.5⁻11.6), and 4.8 (2.7⁻8.5) and 9.0 (5.6⁻14.4), respectively. The ORs of LLF, PD, and LM among those residing in slate-dense areas were 5.5 (3.3⁻9.0), 8.8 (5.6⁻13.8), and 20.5 (10.4⁻40.4), respectively. Substantial proportions of citizens residing in industrialized cities have potentially been exposed to asbestos, and various exposure routes are associated with the development of ARDs. Given the limitations of this study, including potential confounders such as socioeconomic status, further research is needed.


Assuntos
Amianto/toxicidade , Exposição Ambiental/efeitos adversos , Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais/toxicidade , Pneumopatias/induzido quimicamente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Habitação , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , República da Coreia , Características de Residência , Fatores de Risco , Saúde da População Urbana
5.
Biochem Biophys Res Commun ; 477(2): 181-7, 2016 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-27297113

RESUMO

Nucleolar phosphoprotein 140 (Nopp140) is a nucleolar protein, more than 80% of which is disordered. Previous studies have shown that the C-terminal region of Nopp140 (residues 568-596) interacts with protein kinase CK2α, and inhibits the catalytic activity of CK2. Although the region of Nopp140 responsible for the interaction with CK2α was identified, the structural features and the effect of this interaction on the structure of Nopp140 have not been defined due to the difficulty of structural characterization of disordered protein. In this study, the disordered feature of Nopp140 and the effect of CK2α on the structure of Nopp140 were examined using single-molecule fluorescence resonance energy transfer (smFRET) and electron paramagnetic resonance (EPR). The interaction with CK2α was increased conformational rigidity of the CK2α-interacting region of Nopp140 (Nopp140C), suggesting that the disordered and flexible conformation of Nopp140C became more rigid conformation as it binds to CK2α. In addition, site specific spin labeling and EPR analysis confirmed that the residues 574-589 of Nopp140 are critical for binding to CK2α. Similar technical approaches can be applied to analyze the conformational changes in other IDPs during their interactions with binding partners.


Assuntos
Proteínas Nucleares/química , Proteínas Nucleares/ultraestrutura , Fosfoproteínas/química , Fosfoproteínas/ultraestrutura , Sítios de Ligação , Caseína Quinase II/química , Caseína Quinase II/ultraestrutura , Ativação Enzimática , Proteínas Intrinsicamente Desordenadas , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Relação Estrutura-Atividade , Especificidade por Substrato
6.
Plant Cell ; 26(1): 310-24, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24474628

RESUMO

The pollen coat protects pollen grains from harmful environmental stresses such as drought and cold. Many compounds in the pollen coat are synthesized in the tapetum. However, the pathway by which they are transferred to the pollen surface remains obscure. We found that two Arabidopsis thaliana ATP binding cassette transporters, ABCG9 and ABCG31, were highly expressed in the tapetum and are involved in pollen coat deposition. Upon exposure to dry air, many abcg9 abcg31 pollen grains shriveled up and collapsed, and this phenotype was restored by complementation with ABCG9pro:GFP:ABCG9. GFP-tagged ABCG9 or ABCG31 localized to the plasma membrane. Electron microscopy revealed that the mutant pollen coat resembled the immature coat of the wild type, which contained many electron-lucent structures. Steryl glycosides were reduced to about half of wild-type levels in the abcg9 abcg31 pollen, but no differences in free sterols or steryl esters were observed. A mutant deficient in steryl glycoside biosynthesis, ugt80A2 ugt80B1, exhibited a similar phenotype. Together, these results indicate that steryl glycosides are critical for pollen fitness, by supporting pollen coat maturation, and that ABCG9 and ABCG31 contribute to the accumulation of this sterol on the surface of pollen.


Assuntos
Transportadores de Cassetes de Ligação de ATP/fisiologia , Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Glicosídeos/metabolismo , Pólen/fisiologia , Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Membrana Celular/metabolismo , Flores/metabolismo , Pólen/metabolismo
7.
J Phys Chem B ; 117(44): 13866-71, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24111542

RESUMO

Z-DNA binding proteins (ZBPs) specifically recognize and stabilize left-handed double helices, including Z-DNA and Z-RNA. However, the energetics of Z-form stabilization by ZBPs have never been characterized due to the technical limitations of bulk studies, resulting in an unclear understanding of the ZBP operational mechanism at the molecular level. Here, we use single-molecule fluorescence resonance energy transfer (FRET) to determine the energetics of Z-form stabilization by ZBP for DNA, RNA, and DNA-RNA duplexes, revealing that the formation of B-Z or A-Z junctions dominates the thermodynamics and kinetics of Z-form stabilization. Furthermore, in contrast to general assumptions, the Z-form is most efficiently and most rapidly formed in the DNA-RNA hybrid duplex due to the greatly reduced junction energy in the DNA-RNA hybrid.


Assuntos
DNA Forma Z/metabolismo , Proteínas de Ligação a DNA/metabolismo , RNA/metabolismo , DNA Forma Z/química , Proteínas de Ligação a DNA/química , Transferência Ressonante de Energia de Fluorescência , Cinética , Conformação de Ácido Nucleico , Ligação Proteica , RNA/química , Temperatura , Termodinâmica
8.
Plant J ; 65(2): 181-93, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21223384

RESUMO

The exine of the pollen wall shows an intricate pattern, primarily comprising sporopollenin, a polymer of fatty acids and phenolic compounds. A series of enzymes synthesize sporopollenin precursors in tapetal cells, and the precursors are transported from the tapetum to the pollen surface. However, the mechanisms underlying the transport of sporopollenin precursors remain elusive. Here, we provide evidence that strongly suggests that the Arabidopsis ABC transporter ABCG26/WBC27 is involved in the transport of sporopollenin precursors. Two independent mutations at ABCG26 coding region caused drastic decrease in seed production. This defect was complemented by expression of ABCG26 driven by its native promoter. The severely reduced fertility of the abcg26 mutants was caused by a failure to produce mature pollen, observed initially as a defect in pollen-wall development. The reticulate pattern of the exine of wild-type microspores was absent in abcg26 microspores at the vacuolate stage, and the vast majority of the mutant pollen degenerated thereafter. ABCG26 was expressed specifically in tapetal cells at the early vacuolate stage of pollen development. It showed high co-expression with genes encoding enzymes required for sporopollenin precursor synthesis, i.e. CYP704B1, ACOS5, MS2 and CYP703A2. Similar to two other mutants with defects in pollen-wall deposition, abcg26 tapetal cells accumulated numerous vesicles and granules. Taken together, these results suggest that ABCG26 plays a crucial role in the transfer of sporopollenin lipid precursors from tapetal cells to anther locules, facilitating exine formation on the pollen surface.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Biopolímeros/metabolismo , Carotenoides/metabolismo , Pólen/crescimento & desenvolvimento , Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Transporte Biológico/genética , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Infertilidade das Plantas , Pólen/genética , Pólen/metabolismo , Pólen/ultraestrutura , RNA de Plantas/genética , Deleção de Sequência
9.
Proc Natl Acad Sci U S A ; 107(5): 2355-60, 2010 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-20133880

RESUMO

Abscisic acid (ABA) is a ubiquitous phytohormone involved in many developmental processes and stress responses of plants. ABA moves within the plant, and intracellular receptors for ABA have been recently identified; however, no ABA transporter has been described to date. Here, we report the identification of the ATP-binding cassette (ABC) transporter Arabidopsis thaliana Pleiotropic drug resistance transporter PDR12 (AtPDR12)/ABCG40 as a plasma membrane ABA uptake transporter. Uptake of ABA into yeast and BY2 cells expressing AtABCG40 was increased, whereas ABA uptake into protoplasts of atabcg40 plants was decreased compared with control cells. In response to exogenous ABA, the up-regulation of ABA responsive genes was strongly delayed in atabcg40 plants, indicating that ABCG40 is necessary for timely responses to ABA. Stomata of loss-of-function atabcg40 mutants closed more slowly in response to ABA, resulting in reduced drought tolerance. Our results integrate ABA-dependent signaling and transport processes and open another avenue for the engineering of drought-tolerant plants.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sequência de Bases , Membrana Celular/metabolismo , Primers do DNA/genética , Secas , Genes de Plantas , Teste de Complementação Genética , Mutação , Estômatos de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico
10.
Plant J ; 58(5): 737-53, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19207208

RESUMO

AtHMA1 is a member of the heavy metal-transporting ATPase family. It exhibits amino acid sequence similarity to two other Zn(II) transporters, AtHMA2 and AtHMA4, and contains poly-His motifs that are commonly found in Zn(II)-binding proteins, but lacks some amino acids that are typical for this class of transporters. AtHMA1 localizes to the chloroplast envelope. In comparison with wild-type plants, we observed a more pronounced sensitivity in the presence of high Zn(II) concentrations, and increased accumulation of Zn in the chloroplast of T-DNA insertional mutants in AtHMA1. The Zn(II)-sensitive phenotype of AtHMA1 knock-out plants was complemented by the expression of AtHMA1 under the control of its own promoter. The Zn(II)-transporting activity of AtHMA1 was confirmed in a heterologous expression system, Saccharomyces cerevisiae. The sensitivity of yeast to high concentrations of Zn(II) was altered by the expression of AtHMA1 lacking its N-terminal chloroplast-targeting signal. Taken together, these results suggest that under conditions of excess Zn(II), AtHMA1 contributes to Zn(II) detoxification by reducing the Zn content of Arabidopsis thaliana plastids.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Cloroplastos/metabolismo , Zinco/metabolismo , Adenosina Trifosfatases/genética , Sequência de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Teste de Complementação Genética , Dados de Sequência Molecular , Brotos de Planta/genética , Brotos de Planta/metabolismo , RNA de Plantas/genética , Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência
11.
Nat Cell Biol ; 10(10): 1217-23, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18776898

RESUMO

Carbon dioxide uptake and water vapour release in plants occur through stomata, which are formed by guard cells. These cells respond to light intensity, CO2 and water availability, and plant hormones. The predicted increase in the atmospheric concentration of CO2 is expected to have a profound effect on our ecosystem. However, many aspects of CO2-dependent stomatal movements are still not understood. Here we show that the ABC transporter AtABCB14 modulates stomatal closure on transition to elevated CO2. Stomatal closure induced by high CO2 levels was accelerated in plants lacking AtABCB14. Apoplastic malate has been suggested to be one of the factors mediating the stomatal response to CO2 (Refs 4,5) and indeed, exogenously applied malate induced a similar AtABCB14-dependent response as high CO2 levels. In isolated epidermal strips that contained only guard cells, malate-dependent stomatal closure was faster in plants lacking the AtABCB14 and slower in AtABCB14-overexpressing plants, than in wild-type plants, indicating that AtABCB14 catalyses the transport of malate from the apoplast into guard cells. Indeed, when AtABCB14 was heterologously expressed in Escherichia coli and HeLa cells, increases in malate transport activity were observed. We therefore suggest that AtABCB14 modulates stomatal movement by transporting malate from the apoplast into guard cells, thereby increasing their osmotic pressure.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Dióxido de Carbono/farmacologia , Malatos/metabolismo , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/metabolismo , Arabidopsis/citologia , Arabidopsis/efeitos dos fármacos , Transporte Biológico/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Flores/efeitos dos fármacos , Flores/fisiologia , Células HeLa , Humanos , Malatos/farmacologia , Mutação/genética , Estômatos de Plantas/citologia , Transporte Proteico/efeitos dos fármacos , Fatores de Tempo
12.
J Biol Chem ; 283(23): 15893-902, 2008 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-18411273

RESUMO

Cadmium causes the generation of reactive oxygen species, which in turn causes cell damage. We isolated a novel gene from a wheat root cDNA library, which conferred Cd(II)-specific tolerance when expressed in yeast (Saccharomyces cerevisiae). The gene, which we called TaTM20, for Triticum aestivum transmembrane 20, encodes a putative hydrophobic polypeptide of 889 amino acids, containing 20 transmembrane domains arranged as a 5-fold internal repeating unit of 4 transmembrane domains each. Expression of TaTM20 in yeast cells stimulated Cd(II) efflux resulting in a decrease in the content of yeast intracellular cadmium. TaTM20-induced Cd(II) tolerance was maintained in yeast even under conditions of reduced GSH. These results demonstrate that TaTM20 enhances Cd(II) tolerance in yeast through the stimulation of Cd(II) efflux from the cell, partially independent of GSH. Treatment of wheat seedlings with Cd(II) induced their expression of TaTM20, decreasing subsequent root Cd(II) accumulation and suggesting a possible role for TaTM20 in Cd(II) tolerance in wheat.


Assuntos
Cádmio/farmacologia , Farmacorresistência Fúngica/genética , Proteínas de Membrana/biossíntese , Proteínas de Plantas/biossíntese , Proteínas Recombinantes/biossíntese , Saccharomyces cerevisiae/metabolismo , Triticum/genética , DNA Complementar/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Estrutura Terciária de Proteína/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/genética , Saccharomyces cerevisiae/genética , Triticum/metabolismo
13.
Plant Physiol ; 145(3): 831-42, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17827266

RESUMO

P(1B)-type heavy-metal ATPases (HMAs) are transmembrane metal-transporting proteins that play a key role in metal homeostasis. Despite their importance, very little is known about their functions in monocot species. We report the characterization of rice (Oryza sativa) OsHMA9, a member of the P(1B)-type ATPase family. Semiquantitative reverse transcription-polymerase chain reaction analyses of seedlings showed that OsHMA9 expression was induced by a high concentration of copper (Cu), zinc (Zn), and cadmium. We also determined, through promoterbeta-glucuronidase analysis, that the main expression was in the vascular bundles and anthers. The OsHMA9:green fluorescence protein fusion was localized to the plasma membrane. Heterologous expression of OsHMA9 partially rescued the Cu sensitivity of the Escherichia coli copA mutant, which is defective in Cu-transporting ATPases. It did not rescue the Zn sensitivity of the zntA mutant, which is defective in Zn-transporting ATPase. To further elucidate the functional roles of OsHMA9, we isolated two independent null alleles, oshma9-1 and oshma9-2, from the T-DNA insertion population. Mutant plants exhibited the phenotype of increased sensitivity to elevated levels of Cu, Zn, and lead. These results support a role for OsHMA9 in Cu, Zn, and lead efflux from the cells. This article is the first report on the functional characterization of a P(1B)-type metal efflux transporter in monocots.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Transporte/metabolismo , Metais Pesados/metabolismo , Oryza/enzimologia , Adenosina Trifosfatases/genética , Proteínas de Transporte/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Flores/metabolismo , Deleção de Genes , Regulação da Expressão Gênica de Plantas , Oryza/genética , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Caules de Planta/citologia , Caules de Planta/metabolismo
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