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Elucidating kinase-substrate relationships is pivotal for deciphering cellular signaling mechanisms, yet it remains challenging due to the complexity of kinase networks. Herein, we report the development of a versatile DNA-based kinase assay platform for high-throughput profiling of plant protein kinase activities and substrate preferences. Our approach employs DNA-linked peptide substrates, facilitating quantitative and specific kinase activity detection through next-generation DNA sequencing. Leveraging DNA barcodes as quantitative readouts, our approach establishes a high-throughput, sensitive, and specific platform for dissecting kinase-substrate networks in plants, representing a powerful tool for elucidating signaling mechanisms in plants.
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PURPOSE: Common complications of lateral condylar fractures are lateral condylar overgrowth, lateral bony spur and cubitus varus. Lateral condylar overgrowth or lateral bony spur may appear as cubitus varus on gross examination. Such gross cubitus varus without actual angulation is pseudo-cubitus varus, while a difference of more than 5° in varus angulation on X-ray is true cubitus varus. This study aimed to compare true and pseudo-cubitus varus. METHODS: One hundred ninety-two children treated for unilateral lateral condylar fracture with a follow-up period of over six months were included. The Baumann angle, humerus-elbow-wrist angle and interepicondylar width of both side were compared. More than 5° in varus angulation on X-ray was considered cubitus varus. Increase in interepicondylar width was considered lateral condylar overgrowth or a lateral bony spur. The risk factors that could predict the development of a true cubitus varus were analyzed. RESULTS: True cubitus varus was 32.8%, measured by Baumann angle and 29.2%, measured by humerus-elbow-wrist angle. A total of 94.8% of patients showed an increased interepicondylar width. The predicted cut-off value for 5° varus angulation on the Baumann angle was a 3.675 mm increase in interepicondylar width by ROC curve analysis. The risk of cubitus varus in stage 3, 4, and 5 fractures according to Song's classification was 2.88 times higher than that in stage 1 and 2 fractures on multivariable logistic regression analysis. CONCLUSION: Pseudo-cubitus varus is more prevalent than true cubitus varus. A 3.7 mm increase in interepicondylar width could simply predict true cubitus varus. The risk of cubitus varus increased in Song's classification stages 3, 4, and 5.
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Fracturas Óseas , Osteofito , Humanos , Niño , Húmero , Curva ROC , Factores de RiesgoRESUMEN
The phytohormone ethylene controls plant growth and stress responses. Ethylene-exposed dark-grown Arabidopsis seedlings exhibit dramatic growth reduction, yet the seedlings rapidly return to the basal growth rate when ethylene gas is removed. However, the underlying mechanism governing this acclimation of dark-grown seedlings to ethylene remains enigmatic. Here, we report that ethylene triggers the translocation of the Raf-like protein kinase CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), a negative regulator of ethylene signaling, from the endoplasmic reticulum to the nucleus. Nuclear-localized CTR1 stabilizes the ETHYLENE-INSENSITIVE3 (EIN3) transcription factor by interacting with and inhibiting EIN3-BINDING F-box (EBF) proteins, thus enhancing the ethylene response and delaying growth recovery. Furthermore, Arabidopsis plants with enhanced nuclear-localized CTR1 exhibited improved tolerance to drought and salinity stress. These findings uncover a mechanism of the ethylene signaling pathway that links the spatiotemporal dynamics of cellular signaling components to physiological responses.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Etilenos/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas Quinasas/metabolismoRESUMEN
Trigger thumb is an uncommon anomaly in children with controversial management ranging from simple observation to surgical release. This study aimed to determine the clinical outcomes of surgical release versus conservative treatment. Data from 407 children with 511 trigger thumbs were collected from their medical records. To compare the final outcomes of conservative and operative treatments, age at onset, sex, affected side, familial history, treatment modality, time to conversion from conservative to surgical treatment, recurrence, and complications were analyzed. Forty-one children were excluded owing to loss during follow-up; thus, 366 children were finally included. Conservative treatment was administered to 96 children, of whom 25 experienced successful result and 68 experienced treatment failure and were subsequently treated surgically. There were no cases of post-operative recurrence. After 24 months of age, operative treatment had better outcomes than conservative treatment, which showed a higher failure rate.
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Procedimientos Ortopédicos , Trastorno del Dedo en Gatillo , Humanos , Niño , Trastorno del Dedo en Gatillo/cirugía , Tratamiento Conservador , Resultado del Tratamiento , Modalidades de FisioterapiaRESUMEN
The precise regulation of the homeostasis of the cellular proteome is critical for the appropriate growth and development of plants. It also allows the plants to respond to various environmental stresses, by modulating their biochemical and physiological aspects in a timely manner. Ubiquitination of cellular proteins is one of the major protein degradation routes for maintaining cellular protein homeostasis, and ubiquitin E3 ligases, components of ubiquitin ligase complexes, play an important role in the selective degradation of target proteins via substrate-specific interactions. Thus, understanding the role of E3 ligases and their substrate regulation uncovers their specific cellular and physiological functions. Here, we provide protocols for auto- and substrate-ubiquitination analyses that utilize the combination of in vitro purified E3 ubiquitin ligase proteins and immunoprecipitation.
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RATIONALE: Herpes zoster frequently causes dermatomal vesicular rash accompanied by severe neuralgia, and reaching a differential diagnosis may be challenging before the appearance of the vesicular rash. PATIENT CONCERNS: A 40-year-old male patient visited the emergency department with a complaint of sudden onset motor weakness and ipsilateral radiating neuralgia to the Lt. thigh. He had suffered from chickenpox during childhood. DIAGNOSES: No skin lesion was present at the initial visit. The reverse Straight Leg Raise test was negative. Magnetic resonance imaging showed asymmetrically swollen dorsal root ganglion with Gadolinium enhancement. The vesicular rash that appeared on the sixth day after the symptom onset led to the diagnosis of herpes zoster. INTERVENTIONS: Antiviral agent of valacyclovir (1000âmg t.i.d.) was administered for 7 days. OUTCOMES: The patient recovered from motor weaknesses by 2 weeks from the onset of the symptom. Mild degree post-herpetic neuralgia recovered by 2 months. LESSONS: A high index of suspicion is necessary to differentiate early herpes zoster radiculitis before the appearance of vesicular rash from compressive radiculopathy. In L2-3 ipsilateral radiating pain along the dermatome or myotome, the absence of reverse Straight Leg Raise sign may be a possible factor in differentiating herpes zoster radiculitis from compressive radiculopathy.
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Herpes Zóster/complicaciones , Región Lumbosacra/anomalías , Paresia/etiología , Radiculopatía/complicaciones , Adulto , Antivirales/farmacología , Antivirales/uso terapéutico , Medios de Contraste/uso terapéutico , Gadolinio/uso terapéutico , Herpes Zóster/tratamiento farmacológico , Herpes Zóster/fisiopatología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Paresia/tratamiento farmacológico , República de Corea , Valaciclovir/farmacología , Valaciclovir/uso terapéuticoRESUMEN
Ethylene influences plant growth, development, and stress responses via crosstalk with other phytohormones; however, the underlying molecular mechanisms are still unclear. Here, we describe a mechanistic link between the brassinosteroid (BR) and ethylene biosynthesis, which regulates cellular protein homeostasis and stress responses. We demonstrate that as a scaffold, 1-aminocyclopropane-1-carboxylic acid (ACC) synthases (ACS), a rate-limiting enzyme in ethylene biosynthesis, promote the interaction between Seven-in-Absentia of Arabidopsis (SINAT), a RING-domain containing E3 ligase involved in stress response, and ETHYLENE OVERPRODUCER 1 (ETO1) and ETO1-like (EOL) proteins, the E3 ligase adaptors that target a subset of ACS isoforms. Each E3 ligase promotes the degradation of the other, and this reciprocally antagonistic interaction affects the protein stability of ACS. Furthermore, 14-3-3, a phosphoprotein-binding protein, interacts with SINAT in a BR-dependent manner, thus activating reciprocal degradation. Disrupted reciprocal degradation between the E3 ligases compromises the survival of plants in carbon-deficient conditions. Our study reveals a mechanism by which plants respond to stress by modulating the homeostasis of ACS and its cognate E3 ligases.
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Proteínas 14-3-3/metabolismo , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides/metabolismo , Proteínas Portadoras/metabolismo , Liasas/metabolismo , Estrés Fisiológico/fisiología , Proteínas 14-3-3/genética , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas Portadoras/genética , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/fisiología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/fisiología , Homeostasis , Péptidos y Proteínas de Señalización Intracelular/farmacología , Liasas/genética , Isoformas de Proteínas , Estabilidad ProteicaRESUMEN
The phytohormone ethylene regulates plant growth, development, and stress responses. The strict fine-tuning of the regulation of ethylene biosynthesis contributes to the diverse roles of ethylene in plants. Pyridoxal 5'-phosphate-dependent 1-aminocyclopropane-1-carboxylic acid synthase, a rate-limiting enzyme in ethylene biosynthesis, is central and often rate-limiting to regulate ethylene concentration in plants. The post-translational regulation of ACS is a major pathway controlling ethylene biosynthesis in response to various stimuli. We conclude that the regulation of ACS turnover may serve as a central hub for the rapid integration of developmental, environmental, and hormonal signals, all of which influence plant growth and stress responses.
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Arabidopsis , Arabidopsis/genética , Etilenos , Regulación de la Expresión Génica de las Plantas , Desarrollo de la Planta , Reguladores del Crecimiento de las PlantasRESUMEN
The gaseous phytohormone ethylene influences many aspects of plant life, including germination, fruit ripening, senescence, and stress responses. These diverse roles of ethylene occur in part through crosstalk with other phytohormones, which affects ethylene biosynthesis and signaling pathways. We have recently shown that the phytohormones, including gibberellic acid, abscisic acid, auxin, methyl jasmonate, and salicylic acid, regulate the stability of ACC synthases (ACSs), the rate-limiting enzymes in ethylene biosynthesis. Here, we report that treatment of etiolated Arabidopsis seedlings with strigolactone (SL) increases ethylene biosynthesis. SL does not influence ACS stability or ACS gene expression, but it increases the transcript levels of a subset of ACC oxidase (ACO) genes, thereby enhancing ethylene biosynthesis. Taken together with the results of our previous study, these findings demonstrate that most phytohormones differentially regulate ethylene biosynthesis in dark-grown Arabidopsis seedlings by affecting ACS stability and/or the transcript levels of ethylene biosynthesis genes.
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Arabidopsis/efectos de los fármacos , Arabidopsis/metabolismo , Etilenos/metabolismo , Compuestos Heterocíclicos con 3 Anillos/farmacología , Lactonas/farmacología , Plantones/efectos de los fármacos , Plantones/metabolismo , Aminoácido Oxidorreductasas/genética , Aminoácido Oxidorreductasas/metabolismo , Liasas/genética , Liasas/metabolismoRESUMEN
Phosphate (Pi) deficiency severely influences the growth and reproduction of plants. To cope with Pi deficiency, plants initiate morphological and biochemical adaptive responses upon sensing low Pi in the soil, and the plant hormone ethylene plays a crucial role during this process. However, how regulation of ethylene biosynthesis influences the Pi-induced adaptive responses remains unclear. Here, we determine the roles of rice 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS), the rate-limiting enzymes in ethylene biosynthesis, in response to Pi deficiency. Through analysis of tissue-specific expression of OsACS in response to Pi deficiency and OsACS mutants generated by CRISPR/Cas9 [clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9] genome editing, we found that two members of the OsACS family, i.e. OsACS1 and OsACS2, are involved but differed in their importance in controlling the remodeling of root system architecture, transcriptional regulation of Pi starvation-induced genes, and cellular phosphorus homeostasis. Interestingly, in contrast to the known inhibitory role of ethylene on root elongation, both OsACS mutants, especially OsACS1, almost fail to promote lateral root growth in response to Pi deficiency, demonstrating a stimulatory role for ethylene in lateral root development under Pi-deficient conditions. Together, this study provides new insights into the roles of ethylene in Pi deficiency response in rice seedlings and the isoform-specific function of OsACS genes in this process.
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Oryza/fisiología , Fosfatos/deficiencia , Proteínas de Plantas/genética , Etilenos/metabolismo , Edición Génica , Oryza/genética , Oryza/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Plantones/crecimiento & desarrollo , Plantones/fisiologíaRESUMEN
Nitrate reductases (NRs) catalyze the first step in the reduction of nitrate to ammonium. NR activity is regulated by sumoylation through the E3 ligase activity of AtSIZ1. However, it is not clear how NRs interact with AtSIZ1 in the cell, or how nitrogen sources affect NR levels and their cellular localization. Here, we show that the subcellular localization of NRs is modulated by the E3 SUMO (Small ubiquitin-related modifier) ligase AtSIZ1 and that NR protein levels are regulated by nitrogen sources. Transient expression analysis of GFP fusion proteins in onion epidermal cells showed that the NRs NIA1 and NIA2 localize to the cytoplasmic membrane, and that AtSIZ1 localizes to the nucleoplasm, including nuclear bodies, when expressed separately, whereas NRs and AtSIZ1 localize to the nucleus when co-expressed. Nitrate did not affect the subcellular localization of the NRs, but it caused AtSIZ1 to move from the nucleus to the cytoplasm. NRs were not detected in ammonium-treated cells, whereas the localization of AtSIZ1 was not altered by ammonium treatment. NR protein levels increased in response to nitrate but decreased in response to ammonium. In addition, NR protein levels increased in response to a 26S proteasome inhibitor and in cop1-4 and DN-COP1-overexpressing transgenic plants. NR protein degradation occurred later in cop1-4 than in the wild-type, although the NR proteins did not interact with COP1. Therefore, AtSIZ1 controls nuclear localization of NR proteins, and ammonium negatively regulates their levels. The function and stability of NR proteins might be post-translationally modulated by ubiquitination.
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Compuestos de Amonio/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ligasas/metabolismo , Nitrato-Reductasa/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Transporte Activo de Núcleo Celular , Arabidopsis/citología , Proteínas de Arabidopsis/análisis , Núcleo Celular/metabolismo , Ligasas/análisis , Nitrato-Reductasa/análisis , Nitratos/metabolismo , Ubiquitina-Proteína Ligasas/análisisRESUMEN
The gaseous hormone ethylene influences many aspects of plant growth, development, and responses to a variety of stresses. The biosynthesis of ethylene is tightly regulated by various internal and external stimuli, and the primary target of the regulation is the enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS), which catalyzes the rate-limiting step of ethylene biosynthesis. We have previously demonstrated that the regulation of ethylene biosynthesis is a common feature of most of the phytohormones in etiolated Arabidopsis seedlings via the modulation of the protein stability of ACS. Here, we show that various phytohormones also regulate ethylene biosynthesis from etiolated rice seedlings in a similar manner to those in Arabidopsis. Cytokinin, brassinosteroids, and gibberellic acid increase ethylene biosynthesis without changing the transcript levels of neither OsACS nor ACC oxidases (OsACO), a family of enzymes catalyzing the final step of the ethylene biosynthetic pathway. Likewise, salicylic acid and abscisic acid do not alter the gene expression of OsACS, but both hormones downregulate the transcript levels of a subset of ACO genes, resulting in a decrease in ethylene biosynthesis. In addition, we show that the treatment of the phytohormones results in distinct etiolated seedling phenotypes, some of which resemble ethylene-responsive phenotypes, while others display ethylene-independent morphologies, indicating a complicated hormone crosstalk in rice. Together, our study brings a new insight into crosstalk between ethylene biosynthesis and other phytohormones, and provides evidence that rice ethylene biosynthesis could be regulated by the post-transcriptional regulation of ACS proteins.
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Etilenos/biosíntesis , Oryza/metabolismo , Reguladores del Crecimiento de las Plantas/biosíntesis , Oryza/genética , Reguladores del Crecimiento de las Plantas/genética , Plantones/genética , Plantones/metabolismoRESUMEN
The jasmonic acid (JA) and gibberellic acid (GA) signaling pathways interact to coordinate stress responses and developmental processes. This coordination affects plant growth and yield, and is mediated by interactions between the repressors of each pathway, the JASMONATE ZIM-DOMAIN PROTEIN (JAZ) and DELLA proteins. In this study we attempted to identify rice (Oryza sativa) JAZs that interact with rice DELLAs such as SLENDER RICE 1 (SLR1). Analysis of protein-protein interactions showed that OsJAZ8 and OsJAZ9 interact with SLR1; OsJAZ9 also interacted with the SLR1-LIKE (SLRL) protein SLRL2. Based on this broader interaction, we explored the function of OsJAZ9 in JA and GA responses by analyzing transcript levels of the JA-responsive gene OsbHLH148 and the GA-responsive gene OsPIL14 in OsJAZ9-overexpressing (OsJAZ9-Ox) and osjaz9 mutant plants. OsbHLH148 and OsPIL14 encode key transcription factors controlling JA and GA responses, respectively, and JA and GA antagonistically regulate their expression. In OsJAZ9-Ox, the expression of OsbHLH148 was downregulated and the expression of OsPIL14 was upregulated. By contrast, in osjaz9 mutants, the expression of OsbHLH148 was upregulated and the expression of OsPIL14 was downregulated. These observations indicated that OsJAZ9 regulates both JA and GA responses in rice, and this finding was supported by the opposite expression patterns of OsDREB1s, downstream targets of OsbHLH148 and OsPIL14, in the OsJAZ9-Ox and osjaz9 plants. Together, these findings indicate that OsJAZ9 suppresses JA responses and promotes GA responses in rice, and the protein-protein interaction between OsJAZ9 and SLR1 is involved in the antagonistic interplay between JA and GA.
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Ethylene influences many aspects of plant growth and development. The biosynthesis of ethylene is highly regulated by a variety of internal and external cues. A key target of this regulation is 1-aminocyclopropane-1-carboxylic acid (ACC) synthases (ACS), generally the rate-limiting step in ethylene biosynthesis, which is regulated both transcriptionally and post-transcriptionally. Prior studies have demonstrated that cytokinin and brassinosteroid (BR) act as regulatory inputs to elevate ethylene biosynthesis by increasing the stability of ACS proteins. Here, we demonstrate that several additional phytohormones also regulate ACS protein turnover. Abscisic acid, auxin, gibberellic acid, methyl jasmonic acid, and salicylic acid differentially regulate the stability of ACS proteins, with distinct effects on various isoforms. In addition, we demonstrate that heterodimerization influences the stability of ACS proteins. Heterodimerization between ACS isoforms from distinct subclades results in increased stability of the shorter-lived partner. Together, our study provides a comprehensive understanding of the roles of various phytohormones on ACS protein stability, which brings new insights into crosstalk between ethylene and other phytohormones, and a novel regulatory mechanism that controls ACS protein stability through a heterodimerization of ACS isoforms.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Arabidopsis/metabolismo , Liasas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Etilenos/metabolismo , Liasas/genética , Estabilidad ProteicaRESUMEN
Protein kinases are central components of signal transduction pathways in the cell. They catalyze the phosphorylation of substrate proteins, resulting in changes of the activity, localization, stability, and protein interactions of the substrates, ultimately coordinating the activity of important cellular processes. CONSTITUTIVE TRIPLE RESPONSE 1 (CTR1) is a Raf-like protein kinase that functions as a negative regulator in the phytohormone ethylene signaling pathway. CTR1 physically interacts with ethylene receptors via its N-terminal domain at the endoplasmic reticulum, and is involved in suppressing ethylene signaling in the absence of ethylene. Recent studies demonstrated that CTR1 directly interacts with and differentially phosphorylates the positive regulator ETHYLENE INSENSITIVE 2 (EIN2), therefore regulating the movement of EIN2 into the nucleus. Here, we describe protocols for determining the kinase activity of CTR1 by calculating the incorporated radiolabeled phosphate [γ-32P] from ATP into its physiological substrate, EIN2 protein.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Pruebas de Enzimas/métodos , Proteínas Quinasas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Activación Enzimática , Cinética , Mutación , Fosforilación , Proteínas Quinasas/genética , Receptores de Superficie Celular/metabolismo , Especificidad por SustratoRESUMEN
Jasmonic acid (JA) functions in plant development, including senescence and immunity. Arabidopsis thaliana CORONATINE INSENSITIVE 1 encodes a JA receptor and functions in the JA-responsive signaling pathway. The Arabidopsis genome harbors a single COI gene, but the rice (Oryza sativa) genome harbors three COI homologs, OsCOI1a, OsCOI1b, and OsCOI2. Thus, it remains unclear whether each OsCOI has distinct, additive, synergistic, or redundant functions in development. Here, we use the oscoi1b-1 knockout mutants to show that OsCOI1b mainly affects leaf senescence under senescence-promoting conditions. oscoi1b-1 mutants stayed green during dark-induced and natural senescence, with substantial retention of chlorophylls and photosynthetic capacity. Furthermore, several senescence-associated genes were downregulated in oscoi1b-1 mutants, including homologs of Arabidopsis thaliana ETHYLENE INSENSITIVE 3 and ORESARA 1, important regulators of leaf senescence. These results suggest that crosstalk between JA signaling and ethylene signaling affects leaf senescence. The Arabidopsis coi1-1 plants containing 35S:OsCOI1a or 35S:OsCOI1b rescued the delayed leaf senescence during dark incubation, suggesting that both OsCOI1a and OsCOI1b are required for promoting leaf senescence in rice. oscoi1b-1 mutants showed significant decreases in spikelet fertility and grain weight, leading to severe reduction of grain yield, indicating that OsCOI1-mediated JA signaling affects spikelet fertility and grain filling.
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Mutación/genética , Oryza/genética , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/genética , Acetatos/farmacología , Ciclopentanos/farmacología , Oscuridad , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Técnicas de Inactivación de Genes , Genes de Plantas , Prueba de Complementación Genética , Oryza/efectos de los fármacos , Oryza/crecimiento & desarrollo , Oxilipinas/farmacología , Fenotipo , Filogenia , Reguladores del Crecimiento de las Plantas/farmacología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/ultraestructura , Proteínas de Plantas/metabolismo , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Homología de Secuencia de Ácido NucleicoRESUMEN
CORONATINE INSENSITIVE 1 (COI1) encodes an E3 ubiquitin ligase complex component that interacts with JAZ proteins and targets them for degradation in response to JA signaling. The Arabidopsis genome has a single copy of COI1, but the Oryza sativa genome has three closely related COI homologs. To examine the functions of the three OsCOIs, we used yeast two-hybrid assays to examine their interactions with JAZ proteins and found that OsCOIs interacted with OsJAZs and with JAZs, in a coronatine dependent manner. We also tested whether OsCOI1a and OsCOI1b could complement Arabidopsis coi1-1 mutants and found that overexpression of either gene in the coi1-1 mutant resulted in restoration of JA signal transduction and production of seeds, indicating successful complementation. Although OsCOI2 interacted with a few OsJAZs, we were not able to successfully complement the coi1-1 mutant with OsCOI2. Molecular modeling revealed that the three OsCOIs adopt 3D structures similar to COI1. Structural differences resulting from amino acid variations, especially among amino acid residues involved in the interaction with coronatine and JAZ proteins, were tested by mutation analysis. When His-391 in OsCOI2 was substituted with Tyr-391, OsCOI2 interacted with a wider range of JAZ proteins, including OsJAZ1, 2, 5â¼9 and 11, and complemented coi1-1 mutants at a higher frequency than the other OsCOIs and COI1. These results indicate that the three OsCOIs are orthologues of COI1 and play key roles in JA signaling.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Ciclopentanos/química , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oxilipinas/química , Proteínas de Plantas/genética , Transducción de Señal/genética , Secuencia de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Prueba de Complementación Genética , Genoma de Planta , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Oryza/fisiología , Oxilipinas/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Técnicas del Sistema de Dos Híbridos , Ubiquitina-Proteína Ligasas/química , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
The Arabidopsis thaliana transcription factor gene AtMYB44 was induced within 10 min by treatment with methyl jasmonate (MeJA). Wound-induced expression of the gene was observed in local leaves, but not in distal leaves, illustrating jasmonate-independent induction at wound sites. AtMYB44 expression was not abolished in Arabidopsis mutants insensitive to jasmonate (coi1), ethylene (etr1), or abscisic acid (abi3-1) when treated with the corresponding hormones. Moreover, various growth hormones and sugars also induced rapid AtMYB44 transcript accumulation. Thus, AtMYB44 gene activation appears to not be induced by any specific hormone. MeJA-induced activation of jasmonate-responsive genes such as JR2, VSP, LOXII, and AOS was attenuated in transgenic Arabidopsis plants overexpressing the gene (35S:AtMYB44), but significantly enhanced in atmyb44 knockout mutants. The 35S:MYB44 and atmyb44 plants did not show defectiveness in MeJA-induced primary root growth inhibition, indicating that the differences in jasmonate-responsive gene expression observed was not due to alterations in the jasmonate signaling pathway. 35S:AtMYB44 seedlings exhibited slightly elevated chlorophyll levels and less jasmonate- induced anthocyanin accumulation, demonstrating suppression of jasmonate-mediated responses and enhancement of ABA-mediated responses. These observations support the hypothesis of mutual antagonistic actions between jasmonate- and abscisic acid-mediated signaling pathways.
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Ácido Abscísico/metabolismo , Acetatos/metabolismo , Proteínas de Arabidopsis/biosíntesis , Arabidopsis/genética , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Factores de Transcripción/biosíntesis , Antocianinas/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Clorofila/metabolismo , Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/genética , Etilenos/metabolismo , Regulación de la Expresión Génica de las Plantas , Genes abl/genética , Plantas Modificadas Genéticamente , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/genética , Transducción de Señal , Factores de Transcripción/genética , Activación TranscripcionalRESUMEN
OBJECTIVES: The objectives of this communication were to discuss radiographic and magnetic resonance (MR) imaging manifestations and clinical outcome after complete and incomplete resection of the mass of dysplasia epiphysealis hemimelica (DEH). MATERIALS AND METHODS: Clinical records, radiographs, and MR images of eight patients with DEH were retrospectively examined. Six patients were treated by complete excision of the lesional mass, and two patients were treated by incomplete resection at our University Hospitals during the period from 1980 to 2006. RESULTS: We found that, unlike in osteochondroma, DEH was radiographically not clearly separable from the underlying or host bone with preserved cortical bone and marrow continuity. The finding in the talus distinguished DEH from (osteochondroma-like) parosteal osteosarcoma, in which a radiolucent demarcation line clearly separated the tumor from the host bone. The DEH mass had a well-defined low to intermediate signal intensity on T1-weighted images and an intermediate to high signal intensity on T2-weighted images, with irregularity of the articular surface. Simple excision was performed in all patients. The excision was complete in six patients and incomplete in two patients whose lesions was juxta-articular in the ankle and articular in the knee, respectively. The residual mass slowly absorbed and vanished, resulting in mild flaring of the affected portion of the epiphysis. No local recurrence or complication was seen in any of the eight patients. CONCLUSIONS: Although the radiographic signs of DEH are characteristic, (osteochondroma-like) parosteal osteosarcoma should be differentiated from DEH when there is a radiolucent separation line between the mass and host bone in the talus. Simple excision was effective in the management of DEH if the deformity was not complicated. Incompletely excised masses resolved and vanished with time.