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1.
Int Nurs Rev ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38650586

RESUMO

AIMS: This study aims to explore the association between the implementation of the adverse event reporting system (AERS), burnout, and job satisfaction among psychiatric nurses, with a focus on examining the mediating effect of workplace violence from patients. BACKGROUND: Many organizational and personal factors contribute to burnout and job satisfaction experienced by nurses. AERS, serving as a key component of organizational-level quality improvement system, impacts the overall workplace wellness of nurses. METHODS: A national sample of 9,744 psychiatric nurses from 41 psychiatric hospitals across 29 provinces in China participated. Burnout was measured by the Maslach Burnout Inventory. Job satisfaction was measured using the Minnesota Satisfaction Questionnaire. Workplace violence was assessed by nurses' experience of verbal and physical violence. Multilevel linear regression analyses were carried out to examine if AERS impacts burnout and job satisfaction and to identify the mediating role of workplace violence. RESULTS: AERS was positively associated with job satisfaction, but negatively with burnout and workplace violence. Workplace violence exhibited a positive association with burnout and a negative association with job satisfaction. Mediation analyses indicated that the associations between AERS, burnout, and job satisfaction were mediated by workplace violence. CONCLUSIONS: The application of AERS is associated with a reduction in workplace violence in hospitals, which contributes to the diminished burnout and heightened job satisfaction among psychiatric nurses. IMPLICATIONS FOR NURSING PRACTICE AND HEALTH POLICY: The study highlights the importance of organizational efforts and mechanisms in promoting nurses' well-being. It is necessary for hospital management to create a safe workplace through the implementation of AERS.

2.
J Neurosci ; 41(45): 9286-9307, 2021 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-34593604

RESUMO

Adult-onset neurodegenerative diseases are often accompanied by evidence of a chronic inflammation that includes activation of microglial cells and altered levels of brain cytokines. Aspects of this response are likely secondary reactions to neurodegeneration, but for many illnesses the inflammation may itself be an early and even causative disease event. In such cases, the inflammation is referred to as "sterile" as it occurs in the absence of an actual bacterial or viral pathogen. A potent trigger of sterile inflammation in CNS microglia has been shown to be the presence of DNA in the cytoplasm (cytoDNA) induced either by direct DNA damage or by inhibited DNA repair. We have shown that cytoDNA comes from the cell nucleus as a result of insufficient DNA damage repair. Using wild-type and Atm-/- mouse microglia, we extend these observations here by showing that its genomic origins are not random, but rather are heavily biased toward transcriptionally inactive, intergenic regions, in particular repetitive elements and AT-rich sequences. Once released from the genome, in both males and females, we show that cytoDNA is actively exported to the cytoplasm by a CRM1-dependent mechanism. In the cytoplasm, it is degraded either by a cytosolic exonuclease, Trex1, or an autophagy pathway that ends with degradation in the lysosome. Blocking the accumulation of cytoDNA prevents the emergence of the sterile inflammation reaction. These findings offer new insights into the emergence of sterile inflammation and offer novel approaches that may be of use in combatting a wide range of neurodegenerative conditions.SIGNIFICANCE STATEMENT Sterile inflammation describes a state where the defenses of the immune system are activated in the absence of a true pathogen. A potent trigger of this unorthodox response is the presence of DNA in the cytoplasm, which immune cells interpret as an invading virus or pathogen. We show that when DNA damage increases, fragments of the cell's own genome are actively exported to the cytoplasm where they are normally degraded. If this degradation is incomplete an immune reaction is triggered. Both age and stress increase DNA damage, and as age-related neurodegenerative diseases are frequently accompanied by a chronic low-level inflammation, strategies that reduce the induction of cytoplasmic DNA or speed its clearance become attractive therapeutic targets.


Assuntos
Citoplasma/imunologia , Dano ao DNA/imunologia , DNA/imunologia , Inflamação/imunologia , Sequências Repetitivas de Ácido Nucleico/imunologia , Animais , Citoplasma/metabolismo , DNA/metabolismo , Reparo do DNA , Feminino , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/imunologia , Microglia/metabolismo
3.
BMC Genomics ; 23(1): 65, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35057741

RESUMO

BACKGROUND: Soybean is a major legume crop with high nutritional and environmental values suitable for sustainable agriculture. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are important regulators of gene functions in eukaryotes. However, the interactions between these two types of ncRNAs in the context of plant physiology, especially in response to salinity stress, are poorly understood. RESULTS: Here, we challenged a cultivated soybean accession (C08) and a wild one (W05) with salt treatment and obtained their small RNA transcriptomes at six time points from both root and leaf tissues. In addition to thoroughly analyzing the differentially expressed miRNAs, we also documented the first case of miRNA arm-switching (miR166m), the swapping of dominant miRNA arm expression, in soybean in different tissues. Two arms of miR166m target different genes related to salinity stress (chloroplastic beta-amylase 1 targeted by miR166m-5p and calcium-dependent protein kinase 1 targeted by miR166m-3p), suggesting arm-switching of miR166m play roles in soybean in response to salinity stress. Furthermore, two pairs of miRNA:lncRNA interacting partners (miR166i-5p and lncRNA Gmax_MSTRG.35921.1; and miR394a-3p and lncRNA Gmax_MSTRG.18616.1) were also discovered in reaction to salinity stress. CONCLUSIONS: This study demonstrates how ncRNA involves in salinity stress responses in soybean by miRNA arm switching and miRNA:lncRNA interactions. The behaviors of ncRNAs revealed in this study will shed new light on molecular regulatory mechanisms of stress responses in plants, and hence provide potential new strategies for crop improvement.


Assuntos
Glycine max , MicroRNAs , RNA Longo não Codificante , MicroRNAs/genética , RNA Longo não Codificante/genética , RNA de Plantas/genética , Estresse Salino , Glycine max/genética , Transcriptoma
4.
Int J Mol Sci ; 23(14)2022 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-35886893

RESUMO

GTP is an important signaling molecule involved in the growth, development, and stress adaptability of plants. The functions are mediated via binding to GTPases which are in turn regulated by GTPase-activating proteins (GAPs). Satellite reports have suggested the positive roles of GAPs in regulating ABA signaling and pathogen resistance in plants. However, the molecular mechanisms that bring forth the pathogen resistance have remained unclear. In this study, we demonstrated that the expression of AtGAP1 was inducible by Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). The overexpression of AtGAP1 in Arabidopsis promoted the expression of PR1 and the resistance to Pst DC3000. Proteomic analyses revealed the enhanced accumulation of cell-wall-modifying proteins as a result of AtGAP1 overexpression. By microscopic analyses, we showed that the overexpression of AtGAP1 resulted in increased thickness of the mesophyll cell wall and reduced stomatal aperture, which are effective strategies for restricting the entry of foliar pathogens. Altogether, we demonstrated that AtGAP1 increases the resistance to Pst DC3000 in Arabidopsis by promoting cellular strategies that restrict the entry of pathogens into the cells. These results point to a future direction for studying the modes of action of GAPs in regulating plant cell structures and disease resistance.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas Ativadoras de GTPase , Pseudomonas syringae , Solanum lycopersicum , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Parede Celular/fisiologia , Resistência à Doença/genética , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Estômatos de Plantas/fisiologia , Proteômica , Pseudomonas syringae/fisiologia
5.
Biochem J ; 477(20): 3935-3949, 2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-32955089

RESUMO

The unconventional G-protein OsYchF1 plays regulatory roles in plant defense and abiotic stress responses. We have previously resolved the crystal structures of OsYchF1 and its plant-specific regulator, OsGAP1, and determined the residues on OsGAP1 that are essential for its binding to OsYchF1. In this study, we employed site-directed mutagenesis to identify four critical residues on the TGS domain of OsYchF1 that are critical for its binding to OsGAP1. We also generated a docking model of the OsYchF1 : OsGAP1 complex to dissect the molecular basis of their interactions. Our finding not only reveals the roles of the key interacting residues controlling the binding between OsYchF1 and OsGAP1, but also provides a working model on the potential regulatory mechanism mediated by a TGS domain, particularly in the class of GTPase of the OBG family.


Assuntos
Arabidopsis/metabolismo , Domínios C2/genética , Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/genética , Proteínas Ativadoras de GTPase/química , Oryza/química , Proteínas de Plantas/química , Sequência de Aminoácidos , Proteínas de Ligação ao GTP/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Modelos Estruturais , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Domínios Proteicos/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes , Estresse Fisiológico/genética
6.
J Exp Bot ; 71(10): 2970-2981, 2020 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-32061092

RESUMO

Transcription factors (TFs) help plants respond to environmental stresses by regulating gene expression. Up till now, studies on the MYB family of TFs have mainly focused on the highly abundant R2R3-subtype. While the less well-known 1R-subtype has been generally shown to enhance abscisic acid (ABA) sensitivity by acting as transcriptional activators, the mechanisms of their functions are unclear. Here we identified an ABA sensitivity-associated gene from soybean, ABA-Sensitive 1 (GmABAS1), of the 1R-subtype of MYB. Using the GFP-GmABAS1 fusion protein, we demonstrated that GmABAS1 is localized in the nucleus, and with yeast reporter systems, we showed that it is a transcriptional repressor. We then identified the target gene of GmABAS1 to be Glyma.01G060300, an annotated ABI five-binding protein 3 and showed that GmABAS1 binds to the promoter of Glyma.01G060300 both in vitro and in vivo. Furthermore, Glyma.01G060300 and GmABAS1 exhibited reciprocal expression patterns under osmotic stress, inferring that GmABAS1 is a transcriptional repressor of Glyma.01G060300. As a further confirmation, AtAFP2, an orthologue of Glyma.01G060300, was down-regulated in GmABAS1-transgenic Arabidopsis thaliana, enhancing the plant's sensitivity to ABA. This is the first time a 1R-subtype of MYB from soybean has been reported to enhance ABA sensitivity by acting as a transcriptional repressor.


Assuntos
Ácido Abscísico , Glycine max , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Glycine max/genética , Glycine max/metabolismo , Estresse Fisiológico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Int J Mol Sci ; 21(22)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233855

RESUMO

A class of proteins that were discovered to bind the immunosuppressant drug FK506, called FK506-binding proteins (FKBPs), are members of a sub-family of immunophilins. Although they were first identified in human, FKBPs exist in all three domains of life. In this report, a rice FKBP12 homolog was first identified as a biotic stress-related gene through suppression subtractive hybridization screening. By ectopically expressing OsFKBP12 in the heterologous model plant system, Arabidopsis thaliana, for functional characterization, OsFKBP12 was found to increase susceptibility of the plant to the pathogen, Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). This negative regulatory role of FKBP12 in biotic stress responses was also demonstrated in the AtFKBP12-knockout mutant, which exhibited higher resistance towards Pst DC3000. Furthermore, this higher-plant FKBP12 homolog was also shown to be a negative regulator of salt tolerance. Using yeast two-hybrid tests, an ancient unconventional G-protein, OsYchF1, was identified as an interacting partner of OsFKBP12. OsYchF1 was previously reported as a negative regulator of both biotic and abiotic stresses. Therefore, OsFKBP12 probably also plays negative regulatory roles at the convergence of biotic and abiotic stress response pathways in higher plants.


Assuntos
Oryza/genética , Proteínas de Plantas/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Arabidopsis/genética , Arabidopsis/microbiologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Oryza/fisiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/microbiologia , Pseudomonas syringae/patogenicidade , Tolerância ao Sal/genética , Serina-Treonina Quinases TOR/genética , Técnicas do Sistema de Duplo-Híbrido
8.
Int J Mol Sci ; 21(23)2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-33291499

RESUMO

Soybean is an important crop as both human food and animal feed. However, the yield of soybean is heavily impacted by biotic stresses including insect attack and pathogen infection. Insect bites usually make the plants vulnerable to pathogen infection, which causes diseases. Fungi, oomycetes, bacteria, viruses, and nematodes are major soybean pathogens. The infection by pathogens and the defenses mounted by soybean are an interactive and dynamic process. Using fungi, oomycetes, and bacteria as examples, we will discuss the recognition of pathogens by soybean at the molecular level. In this review, we will discuss both the secretory peptides for soybean plant infection and those for pathogen inhibition. Pathogenic secretory peptides and peptides secreted by soybean and its associated microbes will be included. We will also explore the possible use of externally applied antimicrobial peptides identical to those secreted by soybean and its associated microbes as biopesticides.


Assuntos
Produtos Biológicos/farmacologia , Interações Hospedeiro-Patógeno , Peptídeos/farmacologia , Monofosfato de Adenosina/biossíntese , Animais , Antibiose , Bactérias , Agentes de Controle Biológico/química , Agentes de Controle Biológico/farmacologia , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Resistência à Doença , Endófitos , Fungos/fisiologia , Humanos , Imunidade Inata , Oomicetos , Peptídeos/química , Peptídeos/metabolismo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Processamento de Proteína Pós-Traducional , Glycine max/química , Glycine max/imunologia , Virulência , Vírus
9.
N Engl J Med ; 375(12): 1152-60, 2016 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-27653565

RESUMO

BACKGROUND: KAF156 belongs to a new class of antimalarial agents (imidazolopiperazines), with activity against asexual and sexual blood stages and the preerythrocytic liver stages of malarial parasites. METHODS: We conducted a phase 2, open-label, two-part study at five centers in Thailand and Vietnam to assess the antimalarial efficacy, safety, and pharmacokinetic profile of KAF156 in adults with acute Plasmodium vivax or P. falciparum malaria. Assessment of parasite clearance rates in cohorts of patients with vivax or falciparum malaria who were treated with multiple doses (400 mg once daily for 3 days) was followed by assessment of the cure rate at 28 days in a separate cohort of patients with falciparum malaria who received a single dose (800 mg). RESULTS: Median parasite clearance times were 45 hours (interquartile range, 42 to 48) in 10 patients with falciparum malaria and 24 hours (interquartile range, 20 to 30) in 10 patients with vivax malaria after treatment with the multiple-dose regimen and 49 hours (interquartile range, 42 to 54) in 21 patients with falciparum malaria after treatment with the single dose. Among the 21 patients who received the single dose and were followed for 28 days, 1 had reinfection and 7 had recrudescent infections (cure rate, 67%; 95% credible interval, 46 to 84). The mean (±SD) KAF156 terminal elimination half-life was 44.1±8.9 hours. There were no serious adverse events in this small study. The most common adverse events included sinus bradycardia, thrombocytopenia, hypokalemia, anemia, and hyperbilirubinemia. Vomiting of grade 2 or higher occurred in 2 patients, 1 of whom discontinued treatment because of repeated vomiting after receiving the single 800-mg dose. More adverse events were reported in the single-dose cohort, which had longer follow-up, than in the multiple-dose cohorts. CONCLUSIONS: KAF156 showed antimalarial activity without evident safety concerns in a small number of adults with uncomplicated P. vivax or P. falciparum malaria. (Funded by Novartis and others; ClinicalTrials.gov number, NCT01753323 .).


Assuntos
Antimaláricos/administração & dosagem , Imidazóis/administração & dosagem , Malária Falciparum/tratamento farmacológico , Malária Vivax/tratamento farmacológico , Piperazinas/administração & dosagem , Administração Oral , Adulto , Antimaláricos/efeitos adversos , Antimaláricos/farmacocinética , Feminino , Febre , Humanos , Imidazóis/efeitos adversos , Imidazóis/farmacocinética , Masculino , Pessoa de Meia-Idade , Carga Parasitária , Piperazinas/efeitos adversos , Piperazinas/farmacocinética , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Adulto Jovem
10.
J Immunol ; 198(5): 2063-2069, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28137891

RESUMO

Periodic fever with aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is a relatively common autoinflammatory condition that primarily affects children. Although tendencies were reported for this syndrome, genetic variations influencing risk and disease progression are poorly understood. In this study, we performed next-generation sequencing for 82 unrelated PFAPA patients and identified a frameshift variant in the CARD8 gene (CARD8-FS). Subsequently, we compared the frequency of CARD8-FS carriers in our PFAPA cohort (13.9%) with a healthy local population group (3.2%) and found a significant association between the CARD8-FS polymorphism and risk for PFAPA syndrome (p = 0.012; odds ratio: 4.96 [95% confidence interval, 1.33-18.47]). Moreover, CARD8-FS carriers display a distinct PFAPA phenotype that is characterized by a higher prevalence of symptoms out of flares and oral aphthosis (both p = 0.02 compared with PFAPA patients without the frameshift variant). CARD8 encodes a protein component of the NLRP3 inflammasome, which plays an important role in inflammation and contributes to the pathology of various autoinflammatory diseases. We found that the CARD8-FS variant led to a truncated CARD8 protein lacking the FIIND and CARD domains. As a result, the mutant CARD8 protein lost the ability to interact with the NOD domain of NLRP3. In summary, these results identify a new CARD8 variant associated with PFAPA and further suggest that disruption of the interaction between CARD8 and NLRP3 can regulate autoinflammation in patients.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/genética , Febre/genética , Mutação da Fase de Leitura/genética , Doenças Hereditárias Autoinflamatórias/genética , Proteínas de Neoplasias/genética , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Criança , Análise Mutacional de DNA , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Inflamassomos/metabolismo , Linfadenite , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas de Neoplasias/metabolismo , Faringite , Polimorfismo de Nucleotídeo Único , Ligação Proteica/genética , Risco , Estomatite Aftosa , Síndrome
11.
Proc Natl Acad Sci U S A ; 113(10): 2648-53, 2016 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-26912459

RESUMO

G proteins are involved in almost all aspects of the cellular regulatory pathways through their ability to bind and hydrolyze GTP. The YchF subfamily, interestingly, possesses the unique ability to bind both ATP and GTP, and is possibly an ancestral form of G proteins based on phylogenetic studies and is present in all kingdoms of life. However, the biological significance of such a relaxed ligand specificity has long eluded researchers. Here, we have elucidated the different conformational changes caused by the binding of a YchF homolog in rice (OsYchF1) to ATP versus GTP by X-ray crystallography. Furthermore, by comparing the 3D relationships of the ligand position and the various amino acid residues at the binding sites in the crystal structures of the apo-bound and ligand-bound versions, a mechanism for the protein's ability to bind both ligands is revealed. Mutation of the noncanonical G4 motif of the OsYchF1 to the canonical sequence for GTP specificity precludes the binding/hydrolysis of ATP and prevents OsYchF1 from functioning as a negative regulator of plant-defense responses, while retaining its ability to bind/hydrolyze GTP and its function as a negative regulator of abiotic stress responses, demonstrating the specific role of ATP-binding/hydrolysis in disease resistance. This discovery will have a significant impact on our understanding of the structure-function relationships of the YchF subfamily of G proteins in all kingdoms of life.


Assuntos
Trifosfato de Adenosina/química , Proteínas de Ligação ao GTP/química , Nucleosídeo-Trifosfatase/química , Proteínas de Plantas/química , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/microbiologia , Cristalografia por Raios X , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Concentração de Íons de Hidrogênio , Modelos Moleculares , Dados de Sequência Molecular , Nucleosídeo-Trifosfatase/genética , Nucleosídeo-Trifosfatase/metabolismo , Oryza/enzimologia , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Pseudomonas syringae/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Homologia de Sequência de Aminoácidos , Cloreto de Sódio/farmacologia
12.
Int J Mol Sci ; 19(10)2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30336563

RESUMO

In the natural environment, plants are often bombarded by a combination of abiotic (such as drought, salt, heat or cold) and biotic (necrotrophic and biotrophic pathogens) stresses simultaneously. It is critical to understand how the various response pathways to these stresses interact with one another within the plants, and where the points of crosstalk occur which switch the responses from one pathway to another. Calcium sensors are often regarded as the first line of response to external stimuli to trigger downstream signaling. Abscisic acid (ABA) is a major phytohormone regulating stress responses, and it interacts with the jasmonic acid (JA) and salicylic acid (SA) signaling pathways to channel resources into mitigating the effects of abiotic stresses versus defending against pathogens. The signal transduction in these pathways are often carried out via GTP-binding proteins (G-proteins) which comprise of a large group of proteins that are varied in structures and functions. Deciphering the combined actions of these different signaling pathways in plants would greatly enhance the ability of breeders to develop food crops that can thrive in deteriorating environmental conditions under climate change, and that can maintain or even increase crop yield.


Assuntos
Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Estresse Fisiológico , Cálcio/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Proteínas de Plantas/metabolismo
13.
J Biol Chem ; 290(39): 23984-96, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26286751

RESUMO

The C2 domain is one of the most diverse phospholipid-binding domains mediating cellular signaling. One group of C2-domain proteins are plant-specific and are characterized by their small sizes and simple structures. We have previously reported that a member of this group, OsGAP1, is able to alleviate salt stress and stimulate defense responses, and bind to both phospholipids and an unconventional G-protein, OsYchF1. Here we solved the crystal structure of OsGAP1 to a resolution of 1.63 Å. Using site-directed mutagenesis, we successfully differentiated between the clusters of surface residues that are required for binding to phospholipids versus OsYchF1, which, in turn, is critical for its role in stimulating defense responses. On the other hand, the ability to alleviate salt stress by OsGAP1 is dependent only on its ability to bind OsYchF1 and is independent of its phospholipid-binding activity.


Assuntos
Mutagênese Sítio-Dirigida , Oryza/enzimologia , Fosfolipídeos/química , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Proteínas Ativadoras de ras GTPase/química , Proteínas Ativadoras de ras GTPase/metabolismo , Cristalografia por Raios X , Oryza/genética , Fosfolipídeos/genética , Fosfolipídeos/metabolismo , Proteínas de Plantas/genética , Estrutura Terciária de Proteína , Proteínas Ativadoras de ras GTPase/genética
14.
BMC Med Genet ; 17(1): 47, 2016 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-27439461

RESUMO

BACKGROUND: Macular corneal dystrophy (MCD) is a rare autosomal recessive disorder that is characterized by progressive corneal opacity that starts in early childhood and ultimately progresses to blindness in early adulthood. The aim of this study was to identify the cause of MCD in a black South African family with two affected sisters. METHODS: A multigenerational South African Sotho-speaking family with type I MCD was studied using whole exome sequencing. Variant filtering to identify the MCD-causal mutation included the disease inheritance pattern, variant minor allele frequency and potential functional impact. RESULTS: Ophthalmologic evaluation of the cases revealed a typical MCD phenotype and none of the other family members were affected. An average of 127 713 variants per individual was identified following exome sequencing and approximately 1.2 % were not present in any of the investigated public databases. Variant filtering identified a homozygous E71Q mutation in CHST6, a known MCD-causing gene encoding corneal N-acetyl glucosamine-6-O-sulfotransferase. This E71Q mutation results in a non-conservative amino acid change in a highly conserved functional domain of the human CHST6 that is essential for enzyme activity. CONCLUSION: We identified a novel E71Q mutation in CHST6 as the MCD-causal mutation in a black South African family with type I MCD. This is the first description of MCD in a black Sub-Saharan African family and therefore contributes valuable insights into the genetic aetiology of this disease, while improving genetic counselling for this and potentially other MCD families.


Assuntos
Distrofias Hereditárias da Córnea/genética , Mutação , Sulfotransferases/genética , Adulto , Córnea/patologia , Distrofias Hereditárias da Córnea/patologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Masculino , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único , África do Sul , Carboidrato Sulfotransferases
15.
EMBO J ; 29(3): 546-58, 2010 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-19959995

RESUMO

Cytokinesis represents the final stage of eukaryotic cell division during which the cytoplasm becomes partitioned between daughter cells. The process differs to some extent between animal and plant cells, but proteins of the syntaxin family mediate membrane fusion in the plane of cell division in diverse organisms. How syntaxin localization is kept in check remains elusive. Here, we report that localization of the Arabidopsis KNOLLE syntaxin in the plane of cell division is maintained by sterol-dependent endocytosis involving a clathrin- and DYNAMIN-RELATED PROTEIN1A-dependent mechanism. On genetic or pharmacological interference with endocytosis, KNOLLE mis-localizes to lateral plasma membranes after cell-plate fusion. Fluorescence-loss-in-photo-bleaching and fluorescence-recovery-after-photo-bleaching experiments reveal lateral diffusion of GFP-KNOLLE from the plane of division to lateral membranes. In an endocytosis-defective sterol biosynthesis mutant displaying lateral KNOLLE diffusion, KNOLLE secretory trafficking remains unaffected. Thus, restriction of lateral diffusion by endocytosis may serve to maintain specificity of syntaxin localization during late cytokinesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Divisão Celular , Citocinese/fisiologia , Endocitose/fisiologia , Proteínas Qa-SNARE/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/genética , Divisão Celular/fisiologia , Citocinese/genética , Meristema/química , Meristema/metabolismo , Fitosteróis/análise , Fitosteróis/metabolismo , Plantas Geneticamente Modificadas , Proteínas Qa-SNARE/genética , Transdução de Sinais/fisiologia , Fatores de Tempo , Distribuição Tecidual
16.
Genome Res ; 21(2): 227-36, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21177964

RESUMO

Chromatin immunoprecipitation identifies specific interactions between genomic DNA and proteins, advancing our understanding of gene-level and chromosome-level regulation. Based on chromatin immunoprecipitation experiments using validated antibodies, we define the genome-wide distributions of 19 histone modifications, one histone variant, and eight chromatin-associated proteins in Caenorhabditis elegans embryos and L3 larvae. Cluster analysis identified five groups of chromatin marks with shared features: Two groups correlate with gene repression, two with gene activation, and one with the X chromosome. The X chromosome displays numerous unique properties, including enrichment of monomethylated H4K20 and H3K27, which correlate with the different repressive mechanisms that operate in somatic tissues and germ cells, respectively. The data also revealed striking differences in chromatin composition between the autosomes and between chromosome arms and centers. Chromosomes I and III are globally enriched for marks of active genes, consistent with containing more highly expressed genes, compared to chromosomes II, IV, and especially V. Consistent with the absence of cytological heterochromatin and the holocentric nature of C. elegans chromosomes, markers of heterochromatin such as H3K9 methylation are not concentrated at a single region on each chromosome. Instead, H3K9 methylation is enriched on chromosome arms, coincident with zones of elevated meiotic recombination. Active genes in chromosome arms and centers have very similar histone mark distributions, suggesting that active domains in the arms are interspersed with heterochromatin-like structure. These data, which confirm and extend previous studies, allow for in-depth analysis of the organization and deployment of the C. elegans genome during development.


Assuntos
Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Cromossomos/metabolismo , Histonas/metabolismo , Animais , Análise por Conglomerados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Genes Ligados ao Cromossomo X/genética , Histonas/genética , Metilação , Metiltransferases/metabolismo , Membrana Nuclear/metabolismo , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Sequências Repetitivas de Ácido Nucleico/genética
17.
Nat Commun ; 15(1): 15, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167730

RESUMO

SETDB1 is an essential histone methyltransferase that deposits histone H3 lysine 9 trimethylation (H3K9me3) to transcriptionally repress genes and repetitive elements. The function of differential H3K9me3 enrichment between cell-types remains unclear. Here, we demonstrate mutual exclusivity of H3K9me3 and CTCF across mouse tissues from different developmental timepoints. We analyze SETDB1 depleted cells and discover that H3K9me3 prevents aberrant CTCF binding independently of DNA methylation and H3K9me2. Such sites are enriched with SINE B2 retrotransposons. Moreover, analysis of higher-order genome architecture reveals that large chromatin structures including topologically associated domains and subnuclear compartments, remain intact in SETDB1 depleted cells. However, chromatin loops and local 3D interactions are disrupted, leading to transcriptional changes by modifying pre-existing chromatin landscapes. Specific genes with altered expression show differential interactions with dysregulated cis-regulatory elements. Collectively, we find that cell-type specific targets of SETDB1 maintain cellular identities by modulating CTCF binding, which shape nuclear architecture and transcriptomic networks.


Assuntos
Cromatina , Histonas , Animais , Camundongos , Histonas/metabolismo , Metilação de DNA , Retroelementos , Sequências Reguladoras de Ácido Nucleico , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo
18.
Front Plant Sci ; 15: 1339594, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38601302

RESUMO

The tree Eucalyptus camaldulensis is a ubiquitous member of the Eucalyptus genus, which includes several hundred species. Despite the extensive sequencing and assembly of nuclear genomes from various eucalypts, the genus has only one fully annotated and complete mitochondrial genome (mitogenome). Plant mitochondria are characterized by dynamic genomic rearrangements, facilitated by repeat content, a feature that has hindered the assembly of plant mitogenomes. This complexity is evident in the paucity of available mitogenomes. This study, to the best of our knowledge, presents the first E. camaldulensis mitogenome. Our findings suggest the presence of multiple isomeric forms of the E. camaldulensis mitogenome and provide novel insights into minor rearrangements triggered by nested repeat sequences. A comparative sequence analysis of the E. camaldulensis and E. grandis mitogenomes unveils evolutionary changes between the two genomes. A significant divergence is the evolution of a large repeat sequence, which may have contributed to the differences observed between the two genomes. The largest repeat sequences in the E. camaldulensis mitogenome align well with significant yet unexplained structural variations in the E. grandis mitogenome, highlighting the adaptability of repeat sequences in plant mitogenomes.

19.
Plant Cell Environ ; 36(11): 2008-20, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23550829

RESUMO

YchF proteins are a group of mysterious but ubiquitous unconventional G-proteins found in all kingdoms of life except Archaea. Their functions have been documented in microorganisms, protozoa and human, but those of plant YchF homologues are largely unknown. Our group has previously shown that OsYchF1 and its interacting protein, OsGAP1, play opposite roles in plant defense responses. OsGAP1 was found to stimulate the GTPase/ATPase activities of OsYchF1 and regulate its subcellular localization. In this report, we demonstrate that both OsYchF1 and OsGAP1 are localized mainly in the cytosol under NaCl treatment. The ectopic expression of OsYchF1 in transgenic Arabidopsis thaliana leads to reduced tolerance towards salinity stress, while the ectopic expression of OsGAP1 has the opposite effect. Similar results were also obtained with the Arabidopsis homologues, AtYchF1 and AtGAP1, by using AtGAP1 overexpressors and underexpressors, as well as an AtYchF1-knockdown mutant. OsYchF1 and OsGAP1 also exhibit highly significant effects on salinity-induced oxidative stress tolerance. The expression of OsYchF1 suppresses the anti-oxidation enzymatic activities and increases lipid peroxidation in transgenic Arabidopsis, and leads to the accumulation of reactive oxygen species (ROS) in tobacco BY-2 cells, while the ectopic expression of OsGAP1 has the opposite effects in these two model systems.


Assuntos
Nucleosídeo-Trifosfatase/metabolismo , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Salinidade , Tolerância ao Sal , Estresse Fisiológico , Antioxidantes/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/ultraestrutura , Citosol/efeitos dos fármacos , Citosol/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/ultraestrutura , Oxirredução/efeitos dos fármacos , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Tolerância ao Sal/efeitos dos fármacos , Homologia de Sequência de Aminoácidos , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Frações Subcelulares/metabolismo
20.
Nucleic Acids Res ; 39(15): e103, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21646344

RESUMO

Genomic sequences obtained through high-throughput sequencing are not uniformly distributed across the genome. For example, sequencing data of total genomic DNA show significant, yet unexpected enrichments on promoters and exons. This systematic bias is a particular problem for techniques such as chromatin immunoprecipitation, where the signal for a target factor is plotted across genomic features. We have focused on data obtained from Illumina's Genome Analyser platform, where at least three factors contribute to sequence bias: GC content, mappability of sequencing reads, and regional biases that might be generated by local structure. We show that relying on input control as a normalizer is not generally appropriate due to sample to sample variation in bias. To correct sequence bias, we present BEADS (bias elimination algorithm for deep sequencing), a simple three-step normalization scheme that successfully unmasks real binding patterns in ChIP-seq data. We suggest that this procedure be done routinely prior to data interpretation and downstream analyses.


Assuntos
Imunoprecipitação da Cromatina , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Algoritmos , Animais , Composição de Bases , Caenorhabditis elegans/genética , DNA de Helmintos/química
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