Characterization of AtDGK2 in relation to Contact Sites

Contact Sites are conserved cellular regions where two membranes of different organelles are very close but not merged. Contact sites between the endoplasmic reticulum (ER) and the plasma membrane (ER-PM CS) play important roles in metabolic functions. We have identified AtDGK2 (Diacylglycerol kinase 2) as an interactor of SYT1 (Synaptotagmin1), which is a protein located at ER-PM CS. DGKs phosphorylate diacylglycerol to produce phosphatidic acid, both important signalling molecules. Arabidopsis thaliana has seven AtDGKs, but only AtDGK1 and AtDGK2 present an ER transmembrane domain, the rest are cytoplasmic. We have analysed the subcellular localization and functions of these two proteins.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. BIO2017-82609-

Undercovering the molecular mechanisms of lipid signalling at ER-PM contact sites in tomato (Solanum lycopersicum) under abiotic stress conditions

Abiotic stresses cause large reductions in crop production. Therefore, is important to understand how plants respond in order to develop varieties with increased resistance. Lipid-transport proteins (LTP) are emerging as key players of lipid signaling in response to numerous stresses. Specifically, SYT1, a protein first identified by its role in abiotic stress tolerance, is now recognized as an endoplasmic reticulum-plasma membrane contact site tether capable. Our recent data support that SYT1 in involved on non-vesicular lipid-transport of diacyl glycerol (DAG) through its SMP domain. This data together with the interaction of SYT1 with a diacyl glycerol kinase (DGK) suggest a lipid signaling pathway where the product of phospholipase C, diacylglycerol, might be simultaneously translocated from the plasma membrane to the endoplasmic-reticulum by SYT1 and phosphorylated to phosphatidic acid by DGK at the plasma membrane. Using in vitro biochemical approaches we are investigating the affinity of specific lipid species transported by SYT1 using lipid-competition assays, where a fluorescent lipid competes for SYT1 binding-pocket with different lipid species. Using bioinformatic we are obtaining insight into the lipid signal pathway involving PHOSPHOLIPASE C (PLC), DIACYLGLYCEROL KINASE (DGK) and SYNAPTOTAGMIN1 (SYT1) in tomatoUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Role of Arabidopsis DGK1 and DGK2 in cold stress

There are regions, present in all eukaryotic cells, where the membranes of two different organelles are very close (10-30nm), but without fusion, due to proteins which act as tether. These regions are named Membrane Contact Sites (MCS), as for example those formed by endoplasmic reticulum (ER) and plasma membrane (PM). ER-PM CS play important roles in communication between membranes, lipid homeostasis and Ca2+ influx. When a plant is challenge with a stress, phospholipase C is activated at PM producing diacylglycerol (DAG) and inositol phosphates from the hydrolysis of PIP(4,5)P2 or PI4P. DAG is then phosphorylated by diacylglycerol kinases (DGKs) producing phosphatidic acid (PA). Both, DAG and PA, are molecules involved in signalling (Arisz et al., 2009). The genome of Arabidopsis thaliana contain 7 genes encoding DGKs. Most of them are predicted to be cytosolic, with only DGK1 and DGK2 are anchored to the ER due a transmembrane domain. Using different approaches (Co-Immunoprecipitation, confocal microscopy, FRET, Tap-tag…), our group has uncover, that AtDGK1 and AtDGK2 (Diacylglycerol kinase 1, AT5G07920 and Diacylglycerol kinase 2, At5g63770) form a complex with the lipid transport protein located at ER-PM CS known as Synaptotagmin1 (SYT1, At2g20990) (Pérez-Sancho et al., 2015). SYT1 is able to bind preferentially DAG (Ruiz-Lopez et al., 2021), which support the idea that SYT1, DGK1, and DGK2 function coordinated to regulate the levels of DAG at the PM. DGK1 and DGK2 are induced upon low temperatures and found that dgk2 mutants show reduced root growth in low temperature and have reduced freezing tolerance. Our studies suggest that DGK1 and DGK2 act in concert with SYT1 to regulate the production of DAG and PA at ER-PM CS and highlight the importance of these proteins for the correct response to stress.The authors acknowledge the support by: (1) Ministerio de Ciencia e Innovación BIO2017-82609-R, PGC2018-098789-B-100; (2) Ministerio de Economía, Industria y Competitividad (BES-2015-071256, RyC-2013-12699). Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The role of DGK1 and DGK2 in Membrane Contact Sites and Stress Tolerance

All eukaryotic cells present regions where the membranes of two different organelles are very close (10-30 nm) without fusion, mediated by tether proteins. These regions are known as Membrane Contact Sites (MCS). Contact sites between the endoplasmic reticulum and plasma membrane (ER-PM CS) play important roles in communication, lipid and Ca2+ homeostasis. Upon stress perception, phospholipase C (PLC) is activated at the plasma membrane producing diacylglycerol (DAG) and inositol phosphates from the hydrolysis of PIP(4,5)P2 or PI4P. DAG has an amphipathic structure with a hydrophobic region and a small polar head. In normal conditions DAG has a low concentration, 1% of total polar lipids (Gaude et al., 2007). Accumulation of DAG produces a negative curvature stress due to its small polar head that destabilizes the PM (Campomanes et al., 2019; Putta et al., 2016). Thus, DAG concentration must be finely controlled. DAG is phosphorylated by diacylglycerol kinases (DGKs) producing phosphatidic acid (PA). Both, DAG and PA, are important molecules involved in signalling (Arisz et al., 2009). The Arabidopsis thaliana genome contains seven genes encoding DGKs. While most of them are cytosolic (DGK3-DGK7), DGK1 and DGK2 possess a transmembrane domain that anchor them to the ER. Using different approaches we show that DGK1 (AT5G07920) and DGK2 (AT5G63770) form a complex with Synaptotagmin1 (SYT1, At2g20990), a protein tether located at ER-PM CS (Pérez-Sancho et al., 2015). SYT1 is able to bind preferentially DAG (Ruiz-Lopez et al., 2021), which support the idea of being working together with DGK1 and DGK2. DGK1 and DGK2 transcripts increase after cold treatment and a dgk2 mutant shows reduced root growth under low temperature and a low freezing tolerance. Our studies suggest that DGK1 and DGK2 act in concert with SYT1 to regulate the production of PA at ER-PM CS and highlight the importance of these proteins in stress tolerance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Análisis de factores emergentes que impulsan la competitividad en las empresas y su impacto en el crecimiento económico regional: Analysis of emerging factors that impulse competitiveness in companies and their impact on regional economic growth

En el 2020 se presentó un fenómeno de desaceleración empresarial originado por la crisis sanitaria provocado por el Sars-Cov-2 impactando a nivel mundial y en el que el municipio de San Pedro Coahuila no fue la excepción. Los efectos se han reflejado en baja productividad en las empresas, elevada rotación de trabajadores por contagios, déficit financiero e inclusive clausura por quebranto económico. En este contexto, esta investigación tiene por objetivo identificar los factores emergentes que impulsan el crecimiento y la competitividad de las PYMES y cómo influencian en el desarrollo económico regional de San Pedro Coahuila.  De esta manera, se identifican prácticas de las unidades productivas para hacer frente a la recesión que hoy viven. La metodología contempló un diseño no experimental de enfoque mixto, con corte transversal. En la parte cualitativa se realizó un análisis documental sobre las corrientes teóricas del tema y entrevistas. Para la recolección de datos en la parte cuantitativa se utilizó una encuesta con 0.820 alfa de Cronbach. La muestra son empresas de la ciudad de San Pedro Coahuila estratificadas como PYMES. Los resultados muestran que entre los factores emergentes se identifican calidad, mercadotecnia, y planeación estratégica. Como áreas vulnerables se evidencían factores tecnológicos

Optimization of the physic, optical and mechanical properties of a composite edible films of gelatin, whey protein and chitosan

Artículo indizadoThe aim of this work was to evaluate the effect of the concentration of gelatin (G) (3–6 g), whey protein (W) (2.5–7.5 g) and chitosan (C) (0.5–2.5 g) on the physical, optical and mechanical properties of composite edible films (CEFs) using the response surface methodology (RSM), as well as optimizing the formulation for the packaging of foods. The results of the study were evaluated via first‐ and second‐order multiple regression analysis to obtain the determination coefficient val‐ ues with a good fit (R ˃ 0.90) for each of the response variables, except for the values of solubility and b*. The individual linear effect of the independent variables (the concentrations of gelatin, whey protein and chitosan) significantly affected (p ≤ 0.05) the water vapor permeability (WVP), strength and solubility of the edible films. The WVP of the edible films varied from 0.90 to 1.62 × 10−11 g.m/Pa.s.m2, the resistance to traction varied from 0.47 MPa to 3.03 MPa and the solubility varied from 51.06% to 87%. The optimized values indicated that the CEF prepared with a quantity of 4 g, 5 g and 3 g of gelatin, whey protein and chitosan, respectively, provided the CEF with a smooth, continuous and transparent surface, with L values that resulted in a light‐yellow hue, a lower WVP, a maximum strength (resistance to traction) and a lower solubility. The results revealed that the optimized formulation of the CEF of G–W–C allowed a good validation of the prediction model and could be applied, in an effective manner, to the food packaging industry, which could help in miti‐ gating the environmental issues associated with synthetic packaging materials.Consejo Nacional de Ciencia y Tecnologí

Factors that trigger childhood obesity, a public health problem

Obesity is a global pandemic and children are a vulnerable group. Obesity in childhood and adolescence has a negative impact on the health and burden of diseases at that stage of life and later on in adulthood. Therefore, it is crucial to seek strategies and interventions that prevent overweight and obesity in children and adolescents to improve the health conditions of a country. Aim. To determine the triggers of childhood obesity in Hidalgo as a public health problem in children aged 6 to 12 years. Material and methods. For the study the population relative to the parents will be taken as reference point, being a secondary source, of students of the six grades of primary education that comprise ages of 6 to 12 years. Results. The results show that 100% of people are aware of the concept of childhood obesity, but they continue with bad habits such as sedentary lifestyle and the consumption of junk food. Conclusion. People are aware of what childhood obesity is and the problems or consequences that it brings ith it, however, obesity and sedentary lifestyle predominate in several homes, and despite this knowledge, they do not modify their routine or their diet, Which is very important to prevent chronic degenerative diseases such as diabetes, hypertension, dyslipidemia and atherosclerosis

Control de Talponia batesi Henrich (Lepidoptera: Tortricidae) mediante embolsado de frutos en chirimoya (Annona cherimola Mill.)

Se evaluó la eficiencia de tres tipos de embolsado de frutos en dos cultivares y una selección local de chirimoya (‘Concha lisa’, ‘Bays’ y Selene) para el control de Talponia batesi, as´ı como su efecto sobre variables morfométricas de calidad de los frutos. Los tratamientos fueron: testigo (sin embolsar), embolsado de frutos con polipropileno, polietileno y papel encerado. Los tratamientos con bolsas de papel encerado y polietileno tuvieron una eficiencia del 70 y 60 %; aquellos con polipropileno y testigo fueron los más afectados con 82 y 92% respectivamente. Las otras variables morfométricas mostraron diferencias distintivas en cada cultivar y/o selección como era de suponerse a lo reportado. En Concha lisa y Bays se observó que el tratamiento con mejores resultados fueron las bolsas de papel encerado con el menor número de perforaciones por fruto, 4,2 y 2,4 respectivamente; mientras que en Selene tuvo mejor efecto el polietileno con un promedio de 4,2 perforaciones/fruto; pero en las tres variedades embolsadas con polipropileno fue el menos efectivo seguido del testigo. El embolsado de frutos con papel encerado en los tres cultivares y/o selecciones fue el que obtuvo mejores resultados con solo 4% de semillas dañadas por las larvas de T. batesi