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Out-of-body experiences are scientifically inducible cognitive phenomena attracting global attention due to their application in the Metaverse and medical care. Despite previous studies suggesting that one's native language influences one's cognition, the out-of-body experiences of humans with different native languages have not been investigated separately. This study replicated an experiment from a 2007 study to investigate whether differences in native language affect the ability to have scientifically induced out-of-body experiences. A total of 19 age-matched native English and Japanese speakers completed the experiment in two blocks. Thereafter, their experiences were evaluated using questionnaires, and their responses were compared. Importantly, no significant differences between the English and Japanese native-speaker conditions were found. The results showed that out-of-body experiences were induced similarly in both groups, suggesting that people can have out-of-body experiences as a response to similar stimuli, regardless of their native language. However, differences in participants' introspective reports suggested that their experiences may differ qualitatively, possibly, due to the different linguistic backgrounds. The elucidation of the mechanisms of science-assisted out-of-body experiences that consider different cultural and cognitive characteristics, such as native language, could lead to the investigation of their applications in the borderless Metaverse and medicine.
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BACKGROUND: Persistent facial erythema represents a significant complication in atopic dermatitis (AD) patients undergoing treatment with dupilumab. Stratifying patients based on the erythema course is crucial for elucidating heterogeneous phenotypes and facilitating advanced drug efficacy predictions. OBJECTIVES: This study aimed to identify factors associated with facial erythema severity in dupilumab-treated AD patients and to establish a prediction model for drug response based on the identified factors. METHODS: Data from a retrospective study conducted between July 2018 and July 2021 were collected and analysed. Patients were categorized into three groups via hierarchical clustering based on the course of facial erythema: early remission, low remission and persistent residual. LightGBM, a supervised gradient boosting decision tree algorithm, was employed to discern group differences and construct a prediction model. The model incorporated patient demographic and clinical profiles, including pre- and post-treatment examinations. The model's performance was evaluated using accuracy and the area under the receiver operating characteristic curve (AUC). RESULTS: The binary classification model demonstrated an accuracy of 89.10% and an AUC of 0.862 when distinguishing between early remission and persistent residual patients. The eight prominent factors associated with facial erythema severity included age, sex, lactate dehydrogenase (LDH), immunoglobulin E (IgE), eosinophil count, white blood cell count, Alnus allergy and cedar allergy. CONCLUSIONS: This study has two main significances: first, three clusters were identified through unsupervised learning; second, a classification model was constructed that proved more accurate than random prediction. The stratification and identification of crucial factors associated with residual facial erythema in dupilumab-treated AD patients lay the foundation for AI-powered prognostic models. This groundwork provides a substantial basis for enhancing future medical AI support in AD treatment selection, potentially improving personalized treatment approaches and outcomes.
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Pattern-recognition receptor (PRR)-triggered immunity (PTI) wards off a wide range of pathogenic microbes, playing a pivotal role in angiosperms. The model liverwort Marchantia polymorpha triggers defense-related gene expression upon sensing components of bacterial and fungal extracts, suggesting the existence of PTI in this plant model. However, the molecular components of the putative PTI in M. polymorpha and the significance of PTI in bryophytes have not yet been described. We here show that M. polymorpha has four lysin motif (LysM)-domain-containing receptor homologs, two of which, LysM-receptor-like kinase (LYK) MpLYK1 and LYK-related (LYR) MpLYR, are responsible for sensing chitin and peptidoglycan fragments, triggering a series of characteristic immune responses. Comprehensive phosphoproteomic analysis of M. polymorpha in response to chitin treatment identified regulatory proteins that potentially shape LysM-mediated PTI. The identified proteins included homologs of well-described PTI components in angiosperms as well as proteins whose roles in PTI are not yet determined, including the blue-light receptor phototropin MpPHOT. We revealed that MpPHOT is required for negative feedback of defense-related gene expression during PTI. Taken together, this study outlines the basic framework of LysM-mediated PTI in M. polymorpha and highlights conserved elements and new aspects of pattern-triggered immunity in land plants.
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Embryophyta , Magnoliopsida , Marchantia , Quitina , Reconocimiento de Inmunidad Innata , Marchantia/genética , Lisina/química , Lisina/genéticaRESUMEN
In Japan, as in other countries around the world, acne vulgaris is a common disease and a frequent reason for patients to consult dermatologists. For optimal management of acne, it is important to understand how available products to support skin health can be used both with and without prescription products. Dermocosmetics can be defined as skincare agents with dermatologically active ingredients that directly support or care for the symptoms of various skin conditions (distinct from vehicle effects). There are products with active ingredients-including familiar ones such as niacinamide, retinol derivatives, and salicylic acid-that target important aspects of acne pathophysiology. Others, including ceramides, glyercin, thermal spring water, and panthenols, may have positive effects on skin barrier function that are useful in managing acne. This publication will discuss the roles of dermocosmetics in acne either as monotherapy to manage the milder forms of acne and help prevent relapses, or as adjuncts to prescription therapy to increase efficacy or adherence and assist in prevention of local adverse effects. Dermocosmetics may also have active ingredients that positively impact the skin microbiome.
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BACKGROUND: Postural sway while standing reflects the degree of sensory integration function. The relationship between static balance and gait parameters in preschool children is essential for understanding which component of gait function is linked to the sensory integration function. RESEARCH QUESTION: We aimed to clarify the relationship between static balance and gait in children, aged 2-6 years, with typical development METHODS: A total of 105 children (48 girls, 57 boys) participated in this study. Static balance parameters were computed using positions at the center of pressure (COP) while standing (COP length, velocity, and sway area). Spatiotemporal parameters during gait were analyzed for stride length, step width, stance time, cadence, coefficient of variation (CV) of step length, and CV of stance time as gait variability. Pearson correlation coefficients were estimated to explore the relationship between age and static balance or gait parameters. Partial correlation analysis controlling for age was also performed to examine the relationship between static balance and gait parameters. RESULTS: A moderate association between age and static balance parameters and between age and gait parameters was found. Partial correlation analysis revealed that the variability parameters of gait were associated with the static balance parameters. No relationship was found between both spatial and temporal gait parameters and static balance parameters. SIGNIFICANCE: Among the gait parameters that are considered to develop in early childhood, gait variability was associated with COP sway while standing, whereas stride length with increasing age was independent of any static balance parameters. Of the spatial, temporal, and variability parameters of gait, only gait variability maybe associated with the development of sensory integration function.
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Marcha , Equilibrio Postural , Preescolar , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Understanding the degree of motor paralysis in stroke patients is important for assessing the severity of functional impairment and predicting functional prognosis. Fugl-MeyerAssessment for the lower extremities (FMA-LE)is a commonly used measure with high reliability and validity, but there is no official translated Japanese version of FMA-LE. OBJECTIVES: This study aimed to develop Japanese FMA-LE and verify its reliability and validity in patients with acute stroke. METHODS: The Japanese FMA-LE was developed following a standardized translation process. The reliability and validity were evaluated in 50 stroke patients at an acute care hospital. Validity was examined by determining the correlation between FMA-LEand Brunnstrom Recovery Stage (BRS), as well as Short Physical Performance Battery (SPPB). Intra-raterand inter-raterrelative reliabilities were evaluated by calculating intra-classcorrelation coefficients (ICCs). Absolute reliability was assessed by determining the standard error of the measurement and minimum detectible change (MDC). Systematic error was also assessed. RESULTS: FMA-LEtotal score was high correlated with BRS (ρ = 0.73,p < .01) and moderately correlated with SPPB (ρ = 0.69,p < .01). For intra-raterreliability, ICC was 0.98 (p < .01), only fixed systematic error was observed (p < .01), and MDC of the FMA-LEtotal score was 1.24. For inter-raterreliability, ICC was 0.98 (p < .01), no systematic error was observed, and MDC of the FMA-LEtotal score was 3.23. CONCLUSIONS: The Japanese FMA-LE was reliable, valid, and useful for evaluating lower extremity function of acute stroke patients.
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Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Humanos , Japón , Extremidad Inferior , Reproducibilidad de los Resultados , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico , Extremidad SuperiorRESUMEN
Plant photoperiodic growth is coordinated by interactions between circadian clock and light signaling networks. How post-translational modifications of clock proteins affect these interactions to mediate rhythmic growth remains unclear. Here, we identify five phosphorylation sites in the Arabidopsis core clock protein TIMING OF CAB EXPRESSION 1 (TOC1) which when mutated to alanine eliminate detectable phosphorylation. The TOC1 phospho-mutant fails to fully rescue the clock, growth, and flowering phenotypes of the toc1 mutant. Further, the TOC1 phospho-mutant shows advanced phase, a faster degradation rate, reduced interactions with PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) and HISTONE DEACETYLASE 15 (HDA15), and poor binding at pre-dawn hypocotyl growth-related genes (PHGs), leading to a net de-repression of hypocotyl growth. NUCLEAR FACTOR Y subunits B and C (NF-YB/C) stabilize TOC1 at target promoters, and this novel trimeric complex (NF-TOC1) acts as a transcriptional co-repressor with HDA15 to inhibit PIF-mediated hypocotyl elongation. Collectively, we identify a molecular mechanism suggesting how phosphorylation of TOC1 alters its phase, stability, and physical interactions with co-regulators to precisely phase PHG expression to control photoperiodic hypocotyl growth.
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Proteínas de Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Factor de Unión a CCAAT/metabolismo , Mutación , Factores de Transcripción/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Regulación de la Expresión Génica de las Plantas , Histona Desacetilasas/metabolismo , Hipocótilo/crecimiento & desarrollo , Hipocótilo/metabolismo , Fosforilación , Proteolisis , Transducción de Señal , Factores de Transcripción/química , Factores de Transcripción/metabolismoRESUMEN
Photosensory adaptation, which can be classified as sensor or effector adaptation, optimizes the light sensing of living organisms by tuning their sensitivity to changing light conditions. During the phototropic response in Arabidopsis (Arabidopsis thaliana), the light-dependent expression controls of blue-light (BL) photoreceptor phototropin 1 (phot1) and its modulator ROOT PHOTOTROPISM2 (RPT2) are known as the molecular mechanisms underlying sensor adaptation. However, little is known about effector adaption in plant phototropism. Here, we show that control of the phosphorylation status of NONPHOTOTROPIC HYPOCOTYL3 (NPH3) leads to effector adaptation in hypocotyl phototropism. We generated unphosphorable and phosphomimetic NPH3 proteins on seven phosphorylation sites in the etiolated seedlings of Arabidopsis. Unphosphorable NPH3 showed a shortening of its retention time in the cytosol and caused an inability to adapt to very low fluence rates of BL (â¼10-5 µmol m-2 s-1) during the phototropic response. In contrast, the phosphomimetic NPH3 proteins had a lengthened retention time in the cytosol and could not enable the adaptation to BL at fluence rates of 10-3 µmol m-2 s-1 or more. Our results indicate that the activation level of phot1 and the corresponding phosphorylation level of NPH3 determine the dissociation rate and the reassociation rate of NPH3 on the plasma membrane, respectively. These mechanisms may moderately maintain the active state of phot1 signaling across a broad range of BL intensities and contribute to the photosensory adaptation of phot1 signaling during the phototropic response in hypocotyls.
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Arabidopsis , Fototropismo , Arabidopsis/genética , Arabidopsis/fisiología , Fosforilación , Fototropismo/fisiología , Transducción de SeñalRESUMEN
In the USA and Germany, pediatric glioblastoma (pGBM) makes up <3% of childhood brain tumors. Occasionally, GBM has multiple contrast lesions and is referred to as multicentric GBM. The current study present a case of a four-year-old female patient presented with headache, vomiting and consciousness disturbance. Radiologically, a neoplastic lesion of the right frontal lobe with hemorrhage, and bilateral thalamus, right temporal and left occipital neoplastic lesions were identified. The right frontal lesion was not continuous to other lesions. It was concluded that the tumor was a multicentric GBM with intra-tumoral hemorrhage. The tumor was pathologically GBM. Following surgery, the patient underwent chemotherapy and radiotherapy, but 11 months after surgery, the patient passed away. This case had features of childhood GBM and multicentric GBM and was difficult to treat.
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PURPOSE: To evaluate whether MediQOL, which was developed as a care cosmetic for sensitive skin, causes a change in skin condition for subjects with dry skin requiring moisture retention. SUBJECTS AND METHODS: This study includes 20 Japanese subjects with dry skin who required moisture retention, as identified by a dermatologist. The subjects used the novel MediQOL products twice a day for four consecutive weeks. A skin evaluation was performed by a dermatologist, and each subject completed a questionnaire prior to the study period and after two and four weeks of MediQOL use. RESULTS: After four weeks of MediQOL use, alleviation of skin dryness, redness, and itchiness was observed in the subjects. The water/oil content of the skin also improved during the study period. CONCLUSION: Four weeks of MediQOL use resulted in the alleviation of skin dryness, redness, and itchiness and balanced the water/oil content of the skin. MediQOL is expected to be effective in improving the condition of various skin types, including oily, mixed, and sensitive skin as well as dry skin.
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Nutrient availability, in particular the availability of sugar [carbon (C)] and nitrogen (N), is important for the regulation of plant metabolism and development. In addition to independent utilization of C and N nutrients, plants sense and respond to the balance of C and N nutrients (C/N-nutrient) available to them. High C/low N-nutrient stress has been shown to arrest early post-germinative growth while promoting progression to senescence in Arabidopsis. Although several signaling components of the C/N-nutrient response have been identified, the inclusive molecular basis of plant C/N-nutrient response remains unclear. This proteome analysis evaluated phosphorylation dynamics in response to high C/low N-nutrient stress. Phosphoproteomics under conditions of C/N-nutrient stress showed a global change in the phosphorylation status of proteins, including plasma membrane H+-ATPase, carbon and nitrogen metabolic enzymes and signaling proteins such as protein kinases and transcription factors. Further analyses suggested that SNF1-related protein kinase 1 (SnRK1) is involved in primary C/N-nutrient signal mediation via the transcriptional regulation of C/N-regulatory kinases. We also identified a leucine-rich repeat receptor-like kinase with extracellular malectin-like domain, named as LMK1, which was shown to possess cell death induction activity in plant leaves. These results provide important insight into the C/N-nutrient signaling pathways connecting nutrition stress to various cellular and physiological processes in plants.
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To optimize growth and development, plants monitor photosynthetic activities and appropriately regulate various cellular processes. However, signaling mechanisms that coordinate plant growth with photosynthesis remain poorly understood. To identify factors that are involved in signaling related to photosynthetic stimuli, we performed a phosphoproteomic analysis with Marchantia polymorpha, an extant bryophyte species in the basal lineage of land plants. Among proteins whose phosphorylation status changed differentially between dark-treated plants and those after light irradiation but failed to do so in the presence of a photosynthesis inhibitor, we identified a B4-group Raf-like kinase, named PHOTOSYNTHESIS-RELATED RAF (MpPRAF). Biochemical analyses confirmed photosynthesis-activity-dependent changes in the phosphorylation status of MpPRAF. Mutations in the MpPRAF gene resulted in growth retardation. Measurement of carbohydrates demonstrated both hyper-accumulation of starch and reduction of sucrose in Mppraf mutants. Neither inhibition of starch synthesis nor exogenous supply of sucrose alleviated the growth defect, suggesting serious impairment of Mppraf mutants in both the synthesis of sucrose and the repression of its catabolism. As a result of the compromised photosynthate metabolism, photosynthetic electron transport was downregulated in Mppraf mutants. A mutated MpPRAF with a common amino acid substitution for inactivating kinase activity was unable to rescue the Mppraf mutant defects. Our results provide evidence that MpPRAF is a photosynthesis signaling kinase that regulates sucrose metabolism.
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Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Marchantia/metabolismo , Fotosíntesis/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/farmacología , Transporte de Electrón , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Marchantia/genética , Fosforilación , Proteínas de Plantas/metabolismo , Proteómica , Transducción de Señal/efectos de los fármacos , Almidón/metabolismo , Sacarosa/metabolismoRESUMEN
The mitochondrion is an organelle that was derived from an endosymbiosis. Although regulation of mitochondrial growth by the host cell is necessary for the maintenance of mitochondria, it is unclear how this regulatory mechanism was acquired. To address this, we studied the primitive unicellular red alga Cyanidioschyzon merolae, which has the simplest eukaryotic genome and a single mitochondrion. Here we show that the C. merolae Aurora kinase ortholog CmAUR regulates mitochondrial division through phosphorylation of mitochondrial division ring components. One of the components, the Drp1 ortholog CmDnm1, has at least four sites phosphorylated by CmAUR. Depletion of the phosphorylation site conserved among eukaryotes induced defects such as mitochondrial distribution on one side of the cell. Taken together with the observation that human Aurora kinase phosphorylates Drp1 in vitro, we suggest that the phosphoregulation is conserved from the simplest eukaryotes to mammals, and was acquired at the primitive stage of endosymbiosis.
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Aurora Quinasas/genética , Aurora Quinasas/metabolismo , Evolución Biológica , Mitocondrias/genética , Mitocondrias/metabolismo , Rhodophyta/genética , Rhodophyta/metabolismo , Aurora Quinasas/química , Mitosis , Fosforilación , Rhodophyta/enzimología , Especificidad por SustratoRESUMEN
Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa et�al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotrophic N-deficient conditions, tar1-1 cells, with a mutation in the TAR1 gene, maintained higher levels of cell viability and lower levels of hydrogen peroxide generation and accumulated higher levels of TAG and starch compared with those of wild type (WT) cells with bubbling of air containing 5% carbon dioxide. Transcriptomic analyses suggested that genes involved in the scavenging of reactive oxygen species are not repressed in tar1-1 cells. In contrast, the mating efficiency and mRNA levels of key regulatory genes for gametogenesis, MID, MTD and FUS, were suppressed in tar1-1 cells. Among the TAR1-dependent phosphopeptides deduced by phosphoproteomic analysis, protein kinases and enzymes related to N assimilation and carbon (C) metabolism are of particular interest. Characterization of these putative downstream factors may elucidate the molecular pathway whereby TAR1 mediates cellular propagation and C and N metabolism in C/N-imbalanced stress conditions.
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Chlamydomonas reinhardtii/metabolismo , Chlamydomonas/metabolismo , Triglicéridos/metabolismo , Carbono/metabolismo , Supervivencia Celular/genética , Supervivencia Celular/fisiología , Peróxido de Hidrógeno/metabolismo , Nitrógeno/metabolismo , Proteínas Quinasas/metabolismoRESUMEN
Sweat includes active components and metabolites, which are needed to maintain skin homeostasis. Component changes in sweat derived from atopic dermatitis (AD) have been reported. To investigate the influence of sweat components on the pathogenesis of AD, we performed a multifaceted assessment, including nuclear magnetic resonance spectroscopy-based metabolomic analysis, and linked these features to clinical features of AD. Distinctive properties of AD sweat are the quite-variation in protein, anti-microbial peptides and glucose concentrations. pH, sodium, and other salt levels in sweat of AD were comparable to that of healthy subjects. Sweat from AD patients with acute inflammation had a more prominent increase in glucose concentration than sweat from healthy individuals or those with AD with chronic inflammation. Topical glucose application delayed recovery of transepidermal water loss in barrier-disrupted mice. Furthermore, the glucose transporter GLUT2 was highly expressed in the lumen of sweat glands from AD patients. AD patients with chronic inflammation had significantly increased GLUT2 mRNA expression and near normal sweat glucose levels. Despite the small sample size in our study, we speculate that the increased glucose levels might be affected by AD severity and phenotype. We hope that this report will bring novel insight into the impact of sweat components on the clinical manifestation of AD.
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Dermatitis Atópica/metabolismo , Transportador de Glucosa de Tipo 2/metabolismo , Glucosa/metabolismo , Metabolómica/métodos , Sudor/química , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Dermatitis Atópica/genética , Femenino , Transportador de Glucosa de Tipo 2/genética , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Glándulas Sudoríparas/metabolismo , Regulación hacia Arriba , Adulto JovenRESUMEN
The cellular functions of two Arabidopsis (Arabidopsis thaliana) one-helix proteins, OHP1 and OHP2 (also named LIGHT-HARVESTING-LIKE2 [LIL2] and LIL6, respectively, because they have sequence similarity to light-harvesting chlorophyll a/b-binding proteins), remain unclear. Tagged null mutants of OHP1 and OHP2 (ohp1 and ohp2) showed stunted growth with pale-green leaves on agar plates, and these mutants were unable to grow on soil. Leaf chlorophyll fluorescence and the composition of thylakoid membrane proteins revealed that ohp1 deletion substantially affected photosystem II (PSII) core protein function and led to reduced levels of photosystem I core proteins; however, it did not affect LHC accumulation. Transgenic ohp1 plants rescued with OHP1-HA or OHP1-Myc proteins developed a normal phenotype. Using these tagged OHP1 proteins in transgenic plants, we localized OHP1 to thylakoid membranes, where it formed protein complexes with both OHP2 and High Chlorophyll Fluorescence244 (HCF244). We also found PSII core proteins D1/D2, HCF136, and HCF173 and a few other plant-specific proteins associated with the OHP1/OHP2-HCF244 complex, suggesting that these complexes are early intermediates in PSII assembly. OHP1 interacted directly with HCF244 in the complex. Therefore, OHP1 and HCF244 play important roles in the stable accumulation of PSII.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Unión a Clorofila/metabolismo , Complejo de Proteína del Fotosistema II/metabolismo , Proteínas de las Membranas de los Tilacoides/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Clorofila/metabolismo , Proteínas de Unión a Clorofila/genética , Regulación de la Expresión Génica de las Plantas , Mutación , Complejo de Proteína del Fotosistema II/genética , Plantas Modificadas Genéticamente , Proteínas de las Membranas de los Tilacoides/genéticaRESUMEN
The induction of rapid cell death is an effective strategy for plants to restrict biotrophic and hemi-biotrophic pathogens at the infection site. However, activation of cell death comes at a high cost, as dead cells will no longer be available for defense responses nor general metabolic processes. In addition, necrotrophic pathogens that thrive on dead tissue, take advantage of cell death-triggering mechanisms. Mechanisms by which plants solve this conundrum remain described. Here, we identify PLANT SMY2-TYPE ILE-GYF DOMAIN-CONTAINING PROTEIN 1 (PSIG1) and show that PSIG1 helps to restrict cell death induction during pathogen infection. Inactivation of PSIG1 does not result in spontaneous lesions, and enhanced cell death in psig1 mutants is independent of salicylic acid (SA) biosynthesis or reactive oxygen species (ROS) production. Moreover, PSIG1 interacts with SMG7, which plays a role in nonsense-mediated RNA decay (NMD), and the smg7-4 mutant allele mimics the cell death phenotype of the psig1 mutants. Intriguingly, the psig1 mutants display enhanced susceptibility to the hemi-biotrophic bacterial pathogen. These findings point to the existence and importance of the SA- and ROS-independent cell death constraining mechanism as a part of the plant immune system.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas Portadoras/genética , Interacciones Huésped-Patógeno/genética , Arabidopsis/crecimiento & desarrollo , Muerte Celular/genética , Regulación de la Expresión Génica de las Plantas , Degradación de ARNm Mediada por Codón sin Sentido , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Dominios Proteicos/genética , Especies Reactivas de Oxígeno/metabolismo , Ácido Salicílico/metabolismoRESUMEN
Perception of microbe-associated molecular patterns by host cell surface pattern recognition receptors (PRRs) triggers the intracellular activation of mitogen-activated protein kinase (MAPK) cascades. However, it is not known how PRRs transmit immune signals to MAPK cascades in plants. Here, we identify a complete phospho-signaling transduction pathway from PRR-mediated pathogen recognition to MAPK activation in plants. We found that the receptor-like cytoplasmic kinase PBL27 connects the chitin receptor complex CERK1-LYK5 and a MAPK cascade. PBL27 interacts with both CERK1 and the MAPK kinase kinase MAPKKK5 at the plasma membrane. Knockout mutants of MAPKKK5 compromise chitin-induced MAPK activation and disease resistance to Alternaria brassicicola PBL27 phosphorylates MAPKKK5 in vitro, which is enhanced by phosphorylation of PBL27 by CERK1. The chitin perception induces disassociation between PBL27 and MAPKKK5 in vivo Furthermore, genetic evidence suggests that phosphorylation of MAPKKK5 by PBL27 is essential for chitin-induced MAPK activation in plants. These data indicate that PBL27 is the MAPKKK kinase that provides the missing link between the cell surface chitin receptor and the intracellular MAPK cascade in plants.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/inmunología , Quitina/metabolismo , MAP Quinasa Quinasa Quinasa 5/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Alternaria/inmunología , Alternaria/patogenicidad , Arabidopsis/enzimología , Arabidopsis/genética , Membrana Celular/metabolismo , Técnicas de Inactivación de Genes , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiologíaRESUMEN
BACKGROUND: Modulation of protein activity by phosphorylation through kinases and subsequent de-phosphorylation by phosphatases is one of the most prominent cellular control mechanisms. Thus, identification of kinase substrates is pivotal for the understanding of many - if not all - molecular biological processes. Equally, the possibility to deliberately tune kinase activity is of great value to analyze the biological process controlled by a particular kinase. RESULTS: Here we have applied a chemical genetic approach and generated an analog-sensitive version of CDKA;1, the central cell-cycle regulator in Arabidopsis and homolog of the yeast Cdc2/CDC28 kinases. This variant could largely rescue a cdka;1 mutant and is biochemically active, albeit less than the wild type. Applying bulky kinase inhibitors allowed the reduction of kinase activity in an organismic context in vivo and the modulation of plant growth. To isolate CDK substrates, we have adopted a two-dimensional differential gel electrophoresis strategy, and searched for proteins that showed mobility changes in fluorescently labeled extracts from plants expressing the analog-sensitive version of CDKA;1 with and without adding a bulky ATP variant. A pilot set of five proteins involved in a range of different processes could be confirmed in independent kinase assays to be phosphorylated by CDKA;1 approving the applicability of the here-developed method to identify substrates. CONCLUSION: The here presented generation of an analog-sensitive CDKA;1 version is functional and represent a novel tool to modulate kinase activity in vivo and identify kinase substrates. Our here performed pilot screen led to the identification of CDK targets that link cell proliferation control to sugar metabolism, proline proteolysis, and glucosinolate production providing a hint how cell proliferation and growth are integrated with plant development and physiology.