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Canopy shade enhances the activity of PHYTOCHROME INTERACTING FACTORs (PIFs) to boost auxin synthesis in the cotyledons. Auxin, together with local PIFs and their positive regulator CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), promotes hypocotyl growth to facilitate access to light. Whether shade alters the cellular redox status thereby affecting growth responses, remains unexplored. Here, we show that, under shade, high auxin levels increased reactive oxygen species and nitric oxide accumulation in the hypocotyl of Arabidopsis. This nitroxidative environment favored the promotion of hypocotyl growth by COP1 under shade. We demonstrate that COP1 is S-nitrosylated, particularly under shade. Impairing this redox regulation enhanced COP1 degradation by the proteasome and diminished the capacity of COP1 to interact with target proteins and to promote hypocotyl growth. Disabling this regulation also generated transversal asymmetries in hypocotyl growth, indicating poor coordination among different cells, which resulted in random hypocotyl bending and predictably low ability to compete with neighbors. These findings highlight the significance of redox signaling in the control of diffuse growth during shade avoidance.
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Proteínas de Arabidopsis , Arabidopsis , Hipocótilo , Especies Reactivas de Oxígeno , Ubiquitina-Proteína Ligasas , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Especies Reactivas de Oxígeno/metabolismo , Hipocótilo/crecimiento & desarrollo , Hipocótilo/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Óxido Nítrico/metabolismo , Ácidos Indolacéticos/metabolismo , Luz , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Oxidación-Reducción , Transducción de SeñalRESUMEN
Glioblastoma (GBM) represents a formidable challenge in oncology, characterized by aggressive proliferation and poor prognosis. Iron metabolism plays a critical player in GBM progression, with dysregulated iron uptake and utilization contributing to tumor growth and therapeutic resistance. Iron's pivotal role in DNA synthesis, oxidative stress, and angiogenesis underscores its significance in GBM pathogenesis. Elevated expression of iron transporters, such as transferrin receptor 1 (TfR1), highlights the tumor's reliance on iron for survival. Innovative treatment strategies targeting iron dysregulation hold promise for overcoming therapeutic challenges in GBM management. Approaches such as iron chelation therapies, induction of ferroptosis to nanoparticle-based drug delivery systems exploit iron-dependent vulnerabilities, offering avenues for enhance treatment efficacy and improve patient outcomes. As research advances, understanding the complexities of iron-mediated carcinogenesis provides a foundation for developing precision medicine approaches tailored to combat GBM effectively. This review explores the intricate relationship between iron metabolism and GBM, elucidating its multifaceted implications and therapeutic opportunities. By consolidating the latest insights into iron metabolism in GBM, this review underscores its potential as a therapeutic target for improving patient care in combination with the standard of care approach.
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Ferroptosis , Glioblastoma , Hierro , Receptores de Transferrina , Humanos , Receptores de Transferrina/metabolismo , Hierro/metabolismo , Ferroptosis/efectos de los fármacos , Glioblastoma/metabolismo , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Animales , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Antígenos CD/metabolismo , Antígenos CD/genética , Quelantes del Hierro/uso terapéutico , Quelantes del Hierro/farmacologíaRESUMEN
Valosin-containing protein (VCP; aka p97), a member of the AAA (ATPases Associated with various cellular Activities) family, has been associated with a wide range of cellular functions. While previous evidence has shown its presence in mammalian sperm, our study unveils its function in mouse sperm. Notably, we found that mouse VCP does not undergo tyrosine phosphorylation during capacitation and exhibits distinct localization patterns. In the sperm head, it resides within the equatorial segment and, following acrosomal exocytosis, it is released and cleaved. In the flagellum, VCP is observed in the principal and midpiece. Furthermore, our research highlights a unique role for VCP in the cAMP/PKA pathway during capacitation. Pharmacological inhibition of sperm VCP led to reduced intracellular cAMP levels that resulted in decreased phosphorylation in PKA substrates and tyrosine residues and diminished fertilization competence. Our results show that in mouse sperm, VCP plays a pivotal role in regulating cAMP production, probably by the modulation of soluble adenylyl cyclase activity.
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AMP Cíclico , Capacitación Espermática , Espermatozoides , Proteína que Contiene Valosina , Animales , Masculino , Capacitación Espermática/efectos de los fármacos , Proteína que Contiene Valosina/metabolismo , Proteína que Contiene Valosina/genética , Espermatozoides/metabolismo , Ratones , AMP Cíclico/metabolismo , Fosforilación , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Adenosina Trifosfatasas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genéticaRESUMEN
Hyperpolarization of the membrane potential (Em), a phenomenon regulated by SLO3 channels, stands as a central feature in sperm capacitation-a crucial process conferring upon sperm the ability to fertilize the oocyte. In vitro studies demonstrated that Em hyperpolarization plays a pivotal role in facilitating the mechanisms necessary for the development of hyperactivated motility (HA) and acrosomal exocytosis (AE) occurrence. Nevertheless, the physiological significance of sperm Em within the female reproductive tract remains unexplored. As an approach to this question, we studied sperm migration and AE incidence within the oviduct in the absence of Em hyperpolarization using a novel mouse model established by crossbreeding of SLO3 knock-out (KO) mice with EGFP/DsRed2 mice. Sperm from this model displays impaired HA and AE in vitro. Interestingly, examination of the female reproductive tract shows that SLO3 KO sperm can reach the ampulla, mirroring the quantity of sperm observed in wild-type (WT) counterparts, supporting that the HA needed to reach the fertilization site is not affected. However, a noteworthy distinction emerges-unlike WT sperm, the majority of SLO3 KO sperm arrive at the ampulla with their acrosomes still intact. Of the few SLO3 KO sperm that do manage to reach the oocytes within this location, fertilization does not occur, as indicated by the absence of sperm pronuclei in the MII-oocytes recovered post-mating. In vitro, SLO3 KO sperm fail to penetrate the ZP and fuse with the oocytes. Collectively, these results underscore the vital role of Em hyperpolarization in AE and fertilization within their physiological context, while also revealing that Em is not a prerequisite for the development of the HA motility, essential for sperm migration through the female tract to the ampulla.
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Nanotechnology has emerged as a cornerstone in contemporary research, marked by the advent of advanced technologies aimed at nanoengineering materials with diverse applications, particularly to address challenges in human health. Among these challenges, antimicrobial resistance (AMR) has risen as a significant and pressing threat to public health, creating obstacles in preventing and treating persistent diseases. Despite efforts in recent decades to combat AMR, global trends indicate an ongoing and concerning increase in AMR. The primary contributors to the escalation of AMR are the misuse and overuse of various antimicrobial agents in healthcare settings. This has led to severe consequences not only in terms of compromised treatment outcomes but also in terms of substantial financial burdens. The economic impact of AMR is reflected in skyrocketing healthcare costs attributed to heightened hospital admissions and increased drug usage. To address this critical issue, it is imperative to implement effective strategies for antimicrobial therapies. This comprehensive review will explore the latest scientific breakthroughs within the metal-organic frameworks and the use of mesoporous metallic oxide derivates as antimicrobial agents. We will explore their biomedical applications in human health, shedding light on promising avenues for combating AMR. Finally, we will conclude the current state of research and offer perspectives on the future development of these nanomaterials in the ongoing battle against AMR.
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Neuropathic pain is a condition with varying origins, including reduced dietary micronutrient intake. Phytate is a polyphosphate found in seeds and grains that can act as an antinutrient due to the ability of sequester essential divalent metals. Here we tested whether moderate dietary phytate intake could alter nociceptive pain. We subjected weaning mice to a chow supplemented with 1% phytate for eight weeks. Body weight gain, glycemic responses, food ingestion, water ingestion, and liver and adipose tissue weights were not altered compared to controls. We observed a decreased mechanical allodynia threshold in the intervention group, although there were no changes in heat- or cold-induced pain. Animals consuming phytate showed reduced spinal cord tumor necrosis factor (TNF), indicating altered inflammatory process. These data provide evidence for a subclinical induction of mechanical allodynia that is independent of phytate consumption in animals with otherwise normal phenotypic pattern.
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Hiperalgesia , Neuralgia , Ratones , Animales , Hiperalgesia/etiología , Ácido Fítico , Médula Espinal , Factor de Necrosis Tumoral alfaRESUMEN
Pollinators such as Apidae bees are vital for ecosystems and food security. Unfortunately, their populations have declined due to several factors including pesticide use. Among them, the organophosphate insecticide chlorpyrifos, poses a global threat, while legacy compounds like organochlorine pesticides (OCPs) easily bioaccumulate, increasing the concern. Bombus pauloensis, a widely distributed native bee in Argentina, is used for commercial pollination; however, information regarding their health status is scarce. This study assessed chlorpyrifos and OCP levels in B. pauloensis (workers and males) and related environmental matrices living from three different land uses schemes, by means of GC-ECD and GC-MS. The ornamental horticulture field (OP) showed the highest total pesticide concentrations in workers (13.1 ng/g), flowers and soils, whereas the organic agriculture field (OA) exhibited the lowest. Chlorpyrifos was the most abundant compound, accounting for at least 20 % of pesticide load across all matrices. The food production horticulture field (FH) had the highest chlorpyrifos concentration in workers, males and soils (5.0, 4.4 and 3.3 ng/g, respectively), suggesting a local greater usage, whereas OA showed the lowest. Regarding OCPs groups, Drins and DDTs were predominant in most matrices, with FH males registering the highest levels (4.0 and 2.5 ng/g, respectively), closely followed by OP. However, metabolites' contribution indicated historical use and atmospheric inputs in all sites. Multivariate analyses confirmed the significance of site and bumblebee sex to explain pesticide composition. Males from all sites exhibited higher chlorpyrifos levels than workers and this trend was similar for some OCP groups. Overall, OA differed from FH and OP, indicating a correlation between production modes and pesticide profiles. This study demonstrates the value of B. pauloensis as a pesticide biomonitor but also offers insights into its populations' health in the area. In this sense, this information could be useful towards the preservation of this crucial pollinator.
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Cloropirifos , Hidrocarburos Clorados , Lepidópteros , Plaguicidas , Abejas , Animales , Ecosistema , Argentina , Plaguicidas/análisis , Hidrocarburos Clorados/análisis , SueloRESUMEN
NADP(H) is a central metabolic hub providing reducing equivalents to multiple biosynthetic, regulatory and antioxidative pathways in all living organisms. While biosensors are available to determine NADP+ or NADPH levels in vivo, no probe exists to estimate the NADP(H) redox status, a determinant of the cell energy availability. We describe herein the design and characterization of a genetically-encoded ratiometric biosensor, termed NERNST, able to interact with NADP(H) and estimate ENADP(H). NERNST consists of a redox-sensitive green fluorescent protein (roGFP2) fused to an NADPH-thioredoxin reductase C module which selectively monitors NADP(H) redox states via oxido-reduction of the roGFP2 moiety. NERNST is functional in bacterial, plant and animal cells, and organelles such as chloroplasts and mitochondria. Using NERNST, we monitor NADP(H) dynamics during bacterial growth, environmental stresses in plants, metabolic challenges to mammalian cells, and wounding in zebrafish. NERNST estimates the NADP(H) redox poise in living organisms, with various potential applications in biochemical, biotechnological and biomedical research.
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Plantas , Pez Cebra , Animales , NADP/metabolismo , Pez Cebra/metabolismo , Oxidación-Reducción , Plantas/genética , Plantas/metabolismo , Cloroplastos/metabolismo , Mamíferos/metabolismoRESUMEN
Oxygenic photosynthesis involves light and dark phases. In the light phase, photosynthetic electron transport provides reducing power and energy to support the carbon assimilation process. It also contributes signals to defensive, repair, and metabolic pathways critical for plant growth and survival. The redox state of components of the photosynthetic machinery and associated routes determines the extent and direction of plant responses to environmental and developmental stimuli, and therefore, their space- and time-resolved detection in planta becomes critical to understand and engineer plant metabolism. Until recently, studies in living systems have been hampered by the inadequacy of disruptive analytical methods. Genetically encoded indicators based on fluorescent proteins provide new opportunities to illuminate these important issues. We summarize here information about available biosensors designed to monitor the levels and redox state of various components of the light reactions, including NADP(H), glutathione, thioredoxin, and reactive oxygen species. Comparatively few probes have been used in plants, and their application to chloroplasts poses still additional challenges. We discuss advantages and limitations of biosensors based on different principles and propose rationales for the design of novel probes to estimate the NADP(H) and ferredoxin/flavodoxin redox poise, as examples of the exciting questions that could be addressed by further development of these tools. Genetically encoded fluorescent biosensors are remarkable tools to monitor the levels and/or redox state of components of the photosynthetic light reactions and accessory pathways. Reducing equivalents generated at the photosynthetic electron transport chain in the form of NADPH and reduced ferredoxin (FD) are used in central metabolism, regulation, and detoxification of reactive oxygen species (ROS). Redox components of these pathways whose levels and/or redox status have been imaged in plants using biosensors are highlighted in green (NADPH, glutathione, H2O2, thioredoxins). Analytes with available biosensors not tried in plants are shown in pink (NADP+). Finally, redox shuttles with no existing biosensors are circled in light blue. APX, ASC peroxidase; ASC, ascorbate; DHA, dehydroascorbate; DHAR, DHA reductase; FNR, FD-NADP+ reductase; FTR, FD-TRX reductase; GPX, glutathione peroxidase; GR, glutathione reductase; GSH, reduced glutathione; GSSG, oxidized glutathione; MDA, monodehydroascorbate; MDAR, MDA reductase; NTRC, NADPH-TRX reductase C; OAA, oxaloacetate; PRX, peroxiredoxin; PSI, photosystem I; PSII: photosystem II; SOD, superoxide dismutase; TRX, thioredoxin.
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Ferredoxinas , Iluminación , NADP/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Ferredoxinas/metabolismo , Peróxido de Hidrógeno/metabolismo , Fotosíntesis , Oxidación-Reducción , Cloroplastos/metabolismo , Glutatión/metabolismo , Oxidorreductasas/metabolismo , Tiorredoxinas/metabolismoRESUMEN
Plant metabolism is finely orchestrated to allow the occurrence of complementary and sometimes opposite metabolic pathways. In part this is achieved by the allosteric regulation of enzymes, which has been a cornerstone of plant research for many decades. The completion of the Arabidopsis genome and the development of the associated toolkits for Arabidopsis research moved the focus of many researchers to other fields. This is reflected by the increasing number of high-throughput proteomic studies, mainly focused on post-translational modifications. However, follow-up 'classical' biochemical studies to assess the functions and upstream signaling pathways responsible for such modifications have been scarce. In this work, we review the basic concepts of allosteric regulation of enzymes involved in plant carbon metabolism, comprising photosynthesis and photorespiration, starch and sucrose synthesis, glycolysis and gluconeogenesis, the oxidative pentose phosphate pathway and the tricarboxylic acid cycle. Additionally, we revisit the latest results on the allosteric control of the enzymes involved in these pathways. To conclude, we elaborate on the current methods for studying protein-metabolite interactions, which we consider will become crucial for discoveries in the future.
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Arabidopsis , Carbono , Carbono/metabolismo , Arabidopsis/metabolismo , Proteómica , Fotosíntesis , Vía de Pentosa Fosfato , Procesamiento Proteico-PostraduccionalRESUMEN
Prostate cancer is a disease with a high incidence and mortality rate in men worldwide. Serum prostate-specific antigens (PSA) are the main circulating biomarker for this disease in clinical practices. In this work, we present a portable and reusable microfluidic device for PSA quantification. This device comprises a polymethyl methacrylate microfluidic platform coupled with electrochemical detection. The platinum working microelectrode was positioned in the outflow region of the microchannel and was modified with carbon nanofibers (CNF)-decorated gold nanoporous (GNP) structures by the dynamic hydrogen bubble template method, through the simultaneous electrodeposition of metal precursors in the presence of CNF. CNF/GNP structures exhibit attractive properties, such as a large surface to volume ratio, which increases the antibody's immobilization capacity and the electroactive area. CNFs/GNP structures were characterized by scanning electron microscopy, energy dispersive spectrometry, and cyclic voltammetry. Anti-PSA antibodies and HRP were employed for the immune-electrochemical reaction. The detection limit for the device was 5 pg mL-1, with a linear range from 0.01 to 50 ng mL-1. The coefficients of variation within and between assays were lower than 4.40%, and 6.15%, respectively. Additionally, its clinical performance was tested in serum from 30 prostate cancer patients. This novel device was a sensitive, selective, portable, and reusable tool for the serological diagnosis and monitoring of prostate cancer.
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Técnicas Biosensibles , Nanopartículas del Metal , Nanofibras , Nanoporos , Neoplasias de la Próstata , Masculino , Humanos , Carbono/química , Antígeno Prostático Específico/análisis , Microfluídica , Oro/química , Nanopartículas del Metal/química , Inmunoensayo/métodos , Neoplasias de la Próstata/diagnóstico , Técnicas Electroquímicas , Técnicas Biosensibles/métodos , Límite de DetecciónRESUMEN
Sugar-alcohols are major photosynthates in plants from the Rosaceae family. Expression of the gene encoding aldose-6-phosphate reductase (Ald6PRase), the critical enzyme for glucitol synthesis in rosaceous species, is regulated by physiological and environmental cues. Additionally, Ald6PRase is inhibited by small molecules (hexose-phosphates and inorganic orthophosphate) and oxidizing compounds. This work demonstrates that Ald6PRase from peach leaves is phosphorylated in planta at the N-terminus. We also show in vitro phosphorylation of recombinant Ald6PRase by a partially purified kinase extract from peach leaves containing Ca2+-dependent protein kinases (CDPKs). Moreover, phosphorylation of recombinant Ald6PRase was inhibited by hexose-phosphates, phosphoenolpyruvate and pyrophosphate. We further show that phosphorylation of recombinant Ald6PRase was maximal using recombinant CDPKs. Overall, our results suggest that phosphorylation could fine-tune the activity of Ald6PRase.
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Prunus persica , Fosforilación , Prunus persica/metabolismo , Fosfatos/metabolismo , Hojas de la Planta/metabolismo , Hexosas/metabolismoRESUMEN
Neuropathic pain is a condition with varying origins, including reduced dietary micronutrient intake. Phytate is a polyphosphate found in seeds and grains that can act as an antinutrient due to the ability of sequester essential divalent metals. Here we tested whether moderate dietary phytate intake could alter nociceptive pain. We subjected weaning mice to a chow supplemented with 1% phytate for eight weeks. Body weight gain, glycemic responses, food ingestion, water ingestion, and liver and adipose tissue weights were not altered compared to controls. We observed a decreased mechanical allodynia threshold in the intervention group, although there were no changes in heat- or cold-induced pain. Animals consuming phytate showed reduced spinal cord tumor necrosis factor (TNF), indicating altered inflammatory process. These data provide evidence for a subclinical induction of mechanical allodynia that is independent of phytate consumption in animals with otherwise normal phenotypic pattern.
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Under adverse conditions such as shade or elevated temperatures, cotyledon expansion is reduced and hypocotyl growth is promoted to optimize plant architecture. The mechanisms underlying the repression of cotyledon cell expansion remain unknown. Here, we report that the nuclear abundance of the BES1 transcription factor decreased in the cotyledons and increased in the hypocotyl in Arabidopsis thaliana under shade or warmth. Brassinosteroid levels did not follow the same trend. PIF4 and COP1 increased their nuclear abundance in both organs under shade or warmth. PIF4 directly bound the BES1 promoter to enhance its activity but indirectly reduced BES1 expression. COP1 physically interacted with the BES1 protein, promoting its proteasome degradation in the cotyledons. COP1 had the opposite effect in the hypocotyl, demonstrating organ-specific regulatory networks. Our work indicates that shade or warmth reduces BES1 activity by transcriptional and post-translational regulation to inhibit cotyledon cell expansion.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas , Hipocótilo/metabolismoRESUMEN
Sugar alcohols are major photosynthetic products in plant species from the Apiaceae and Plantaginaceae families. Mannose-6-phosphate reductase (Man6PRase) and aldose-6-phosphate reductase (Ald6PRase) are key enzymes for synthesizing mannitol and glucitol in celery (Apium graveolens) and peach (Prunus persica), respectively. In this work, we report the first crystal structures of dimeric plant aldo/keto reductases (AKRs), celery Man6PRase (solved in the presence of mannonic acid and NADP+) and peach Ald6PRase (obtained in the apo form). Both structures displayed the typical TIM barrel folding commonly observed in proteins from the AKR superfamily. Analysis of the Man6PRase holo form showed that residues putatively involved in the catalytic mechanism are located close to the nicotinamide ring of NADP+, where the hydride transfer to the sugar phosphate should take place. Additionally, we found that Lys48 is important for the binding of the sugar phosphate. Interestingly, the Man6PRase K48A mutant had a lower catalytic efficiency with mannose-6-phosphate but a higher catalytic efficiency with mannose than the wild type. Overall, our work sheds light on the structure-function relationships of important enzymes to synthesize sugar alcohols in plants.
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Fosfatos , Alcoholes del Azúcar , Oxidorreductasas de Alcohol/metabolismo , Aldehído Reductasa/metabolismo , Secuencia de Aminoácidos , Humanos , Manosafosfatos , NADP/metabolismo , Plantas/metabolismo , AzúcaresRESUMEN
RESUMEN Antecedentes: la pandemia de COVID-19 alteró la formación de los residentes de cirugía, disminuyendo sus oportunidades de aprendizaje. La lectura y análisis de trabajos científicos a través de pódcast podrían ser una opción para atenuar ese problema. Objetivo: evaluar la aceptación por parte de los residentes de Cirugía del uso de pódcast como una nueva herramienta educativa. Material y métodos: estudio exploratorio, analítico y longitudinal, realizado desde mayo hasta diciembre de 2020. Cada semana, un residente fue el encargado de leer, analizar y confeccionar una presentación grabada en forma de pódcast sobre un artículo seleccionado por médicos de planta. Se evaluó la experiencia de los residentes mediante un cuestionario tipo Likert diseñado por los investigadores. Resultados: se realizaron 37 pódcast, que se reprodujeron 2091 veces. El 100% de los residentes informó que esta herramienta fomentó la discusión académica entre pares, el 88% que le generó preguntas de investigación y el 43% que lo inspiró a una revisión bibliográfica. Conclusión: la lectura y análisis de trabajos a través de pódcast es bien aceptada y puede ser una herramienta adicional para el aprendizaje en épocas atípicas.
ABSTRACT Background: COVID-19 pandemic altered the training of residents in surgery, reducing their opportunities to learn. Reading and analyzing scientific paper via podcasts could be an option to mitigate such problem. Objective: The aim of this study is to evaluate residents in surgery acceptance of the use of podcasts as a new educational tool. Material and methods: We conducted a longitudinal, analytical and exploratory study between May and December 2020. Each week, a resident was in charge of reading, analyzing and preparing a recorded presentation in the format of a podcast of an article selected by a staff physician. The residents' experience was assessed by means of a Likert-type questionnaire designed by the investigators. Results: A total of 37 podcasts were recorded with a total number of plays of 2091. All the residents reported that this tool encouraged the academic peer discussion, 88% responded that it generated research questions and 43% agreed that listening to the podcasts served as inspiration to perform a bibliographic search. Conclusion: Reading and analyzing scientific papers via podcasts is well accepted and could be an additional tool for learning in atypical times.
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Cirugía General/educación , Difusión por la Web , COVID-19 , Percepción , Médicos/psicología , Estudios Prospectivos , Educación a Distancia , Internado y Residencia , AprendizajeRESUMEN
KEY MESSAGE: This review outlines research performed in the last two decades on the structural, kinetic, regulatory and evolutionary aspects of ADP-glucose pyrophosphorylase, the regulatory enzyme for starch biosynthesis. ADP-glucose pyrophosphorylase (ADP-Glc PPase) catalyzes the first committed step in the pathway of glycogen and starch synthesis in bacteria and plants, respectively. Plant ADP-Glc PPase is a heterotetramer allosterically regulated by metabolites and post-translational modifications. In this review, we focus on the three-dimensional structure of the plant enzyme, the amino acids that bind the regulatory molecules, and the regions involved in transmitting the allosteric signal to the catalytic site. We provide a model for the evolution of the small and large subunits, which produce heterotetramers with distinct catalytic and regulatory properties. Additionally, we review the various post-translational modifications observed in ADP-Glc PPases from different species and tissues. Finally, we discuss the subcellular localization of the enzyme found in grain endosperm from grasses, such as maize and rice. Overall, this work brings together research performed in the last two decades to better understand the multiple mechanisms involved in the regulation of ADP-Glc PPase. The rational modification of this enzyme could improve the yield and resilience of economically important crops, which is particularly important in the current scenario of climate change and food shortage.
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Evolución Molecular , Glucosa-1-Fosfato Adenililtransferasa/química , Glucosa-1-Fosfato Adenililtransferasa/fisiología , Plantas/enzimología , Regulación Alostérica , Glucosa-1-Fosfato Adenililtransferasa/genética , Modelos Moleculares , Conformación Proteica , Almidón/biosíntesis , Almidón/químicaRESUMEN
MOTIVATION: Large-scale cancer genome projects have generated genomic, transcriptomic, epigenomic and clinicopathological data from thousands of samples in almost every human tumor site. Although most omics data and their associated resources are publicly available, its full integration and interpretation to dissect the sources of gene expression modulation require specialized knowledge and software. RESULTS: We present Multiomix, an interactive cloud-based platform that allows biologists to identify genetic and epigenetic events associated with the transcriptional modulation of cancer-related genes through the analysis of multi-omics data available on public functional genomic databases or user-uploaded datasets. Multiomix consists of an integrated set of functions, pipelines and a graphical user interface that allows retrieval, aggregation, analysis and visualization of different omics data sources. After the user provides the data to be analyzed, Multiomix identifies all significant correlations between mRNAs and non-mRNA genomics features (e.g. miRNA, DNA methylation and CNV) across the genome, the predicted sequence-based interactions (e.g. miRNA-mRNA) and their associated prognostic values. AVAILABILITY AND IMPLEMENTATION: Multiomix is available at https://www.multiomix.org. The source code is freely available at https://github.com/omics-datascience/multiomix. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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MicroARNs , Neoplasias , Humanos , Epigenómica , Nube Computacional , Genómica , Neoplasias/genética , Programas Informáticos , MicroARNs/genética , Transcriptoma , OncogenesRESUMEN
Until recently, the cyanobacterial phylum only included oxygenic photosynthesizer members. The discovery of Melainabacteria as a group of supposed non-photosynthetic cyanobacteria asked to revisit such scenario. From metagenomic data, we were able to identify sequences encoding putative ADP-glucose pyrophosphorylases (ADP-GlcPPase) from free-living and intestinal Melainabacteria. The respective genes were de novo synthesized and over-expressed in Escherichia coli. The purified recombinant proteins from both Melainabacteria species were active as ADP-GlcPPases, exhibiting Vmax values of 2.3 (free-living) and 7.1 U/mg (intestinal). The enzymes showed similar S0.5 values (â¼0.3 mM) for ATP, while the one from the intestinal source exhibited a 6-fold higher affinity toward glucose-1P. Both recombinant ADP-GlcPPases were sensitive to glucose-6P activation (A0.5 â¼0.3 mM) and Pi and ADP inhibition (I0.5 between 0.2 and 3 mM). Interestingly, the enzymes from Melainabacteria were insensitive to 3-phosphoglycerate, which is the principal activator of ADP-GlcPPases from photosynthetic cyanobacteria. As far as we know, this is the first biochemical characterization of an active enzyme from Melainabacteria. This work contributes to a better understanding of the evolution of allosteric regulation in the ADP-GlcPPase family, which is critical for synthesizing the main reserve polysaccharide in prokaryotes (glycogen) and plants (starch). In addition, our results offer further information to discussions regarding the phylogenetic position of Melainabacteria.
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Proteínas Bacterianas/química , Cianobacterias/enzimología , Glucosa-1-Fosfato Adenililtransferasa/química , Filogenia , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Clonación Molecular , Cianobacterias/genética , Glucosa-1-Fosfato Adenililtransferasa/genética , Glucosa-1-Fosfato Adenililtransferasa/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
Introducción: El tabaquismo es un importante problema de salud por su elevada morbimortalidad y prevalencia, siendo el principal factor de riesgo prevenible para enfermedades cardiovasculares, enfermedades respiratorias crónicas y cáncer. La Residencia de Medicina General y Familiar del Hospital General de Agudos Dr. Teodoro Álvarez desarrolló un programa de cesación tabáquica que funciona en el CeSAC N°34 y forma parte del Programa de Prevención y Control del Tabaquismo del Ministerio de Salud del Gobierno de la Ciudad de Buenos Aires desde el año 2012. Objetivos, materiales y métodos: En este estudio descriptivo de corte transversal cuantitativo se evalúa la eficacia de dicho programa y las variables relacionadas con la efectividad en el período entre el 01/04/2017 y el 31/12/2020. Resultados: De los 59 pacientes que fueron finalmente incluídos en el análisis, 24 (40%) lograron la eficacia terapéutica, entendida como haber alcanzado la etapa de mantenimiento. Algunas de las variables incluidas en el análisis estadístico mostraron una mayor correlación con recaídas, como una baja carga tabáquica y la presencia de enfermedades pulmonares crónicas; mientras que otras, como una alta motivación o la presencia de enfermedad cardiovascular se asociaron a un mayor éxito terapéutico. Discusión y conclusiones: El programa presentó una eficacia terapéutica del 40%, cifra mayor que la eficacia de los objetivos planteados por el Ministerio de Salud de Nación. Se encontraron asociaciones entre una mayor eficacia terapéutica y ciertas características de los pacientes, pero se requieren más estudios para confirmar esta hipótesis. (AU)