Search results for " membrana"
showing 10 items of 75 documents
Plasma Membrane Dynamics in Plant-Microbe Interactions
2017
N-glycosylation efficiency is determined by the distance to the C-terminus and the amino acid preceding an Asn-Ser-Thr sequon
2011
N-glycosylation is the most common and versatile protein modification. In eukaryotic cells, this modification is catalyzed cotranslationally by the enzyme oligosaccharyltransferase, which targets the β-amide of the asparagine in an Asn-Xaa-Ser/Thr consensus sequon (where Xaa is any amino acid but proline) in nascent proteins as they enter the endoplasmic reticulum. Because modification of the glycosylation acceptor site on membrane proteins occurs in a compartment-specific manner, the presence of glycosylation is used to indicate membrane protein topology. Moreover, glycosylation sites can be added to gain topological information. In this study, we explored the determinants of N-glycosylati…
Caracterización proteómica de la interacción y la inserción de proteínas de membrana
2019
Las proteínas de membrana tienen funciones muy diversas en la célula, desde controlar el tráfico molecular hasta facilitar la transducción de señales. Sin embargo, el estudio de estas proteínas supone todo un reto por sus particulares características fisico-químicas. Su naturaleza hidrofóbica requiere un elevado control durante su síntesis. Uno de los pasos críticos en esta síntesis es la inserción en la bicapa lipídica. Generalmente, este proceso se produce a través de un mecanismo (co-traduccional) acoplado al proceso de traducción. Esta vía co-traduccional ha sido ampliamente estudiada y la maquinaria implicada en el proceso se conoce con bastante profundidad. Sin embargo, algunas proteí…
Mesoangioblasti di topo producono e rilasciano nello spazio extracellulare vescicole di membrana contenenti MMP9 e FGF2 in forma attiva
2009
Position paper - progress towards standards in integrated (aerobic) MBR modelling.
2020
Membrane bioreactor (MBR) models are useful tools for both design and management. The system complexity is high due to the involved number of processes which can be clustered in biological and physical ones. Literature studies are present and need to be harmonized in order to gain insights from the different studies and allow system optimization by applying a control. This position paper aims at defining the current state of the art of the main integrated MBR models reported in the literature. On the basis of a modelling review, a standardized terminology is proposed to facilitate the further development and comparison of integrated membrane fouling models for aerobic MBRs. ispartof: WATER …
Influence of the C-terminus of the glycophorin A transmembrane fragment on the dimerization process
2000
The monomer-dimer equilibrium of the glycophorin A (GpA) transmembrane (TM) fragment has been used as a model system to investigate the amino acid sequence requirements that permit an appropriate helix-helix packing in a membrane‐mimetic environment. In particular, we have focused on a region of the helix where no crucial residues for packing have been yet reported. Various deletion and replacement mutants in the C‐terminal region of the TM fragment showed that the distance between the dimerization motif and the flanking charged residues from the cytoplasmic side of the protein is important for helix packing. Furthermore, selected GpA mutants have been used to illustrate the rearrangement o…
Diepoxyrollin and Diepomuricanin B: Two New Diepoxyacetogenins from Rollinia membranacea Seeds
1997
Diepoxyrollin (1) and diepomuricanin B (2), two new Annonaceous acetogenins were isolated from the cytotoxic MeOH extract of the seeds of Colombian Rollinia membranacea. Five others known acetogenins were also isolated, dieporeticanin 1, dieporeticanin 2, diepomuricanin A, rollinone, and sylvaticin. Their structures were elucidated on the basis of spectral data. Compounds 1 and 2 belong to the rare type of diepoxyacetogenins, which are probably precursors of the mono-tetrahydrofuran acetogenins.
Réponses des cellules de Nicotiana tabacum à des molécules microbiennes : évènements de signalisation précoce, influence de la dynamique membranaire …
2018
In their natural environment plants are in close interaction with beneficial, neutral, or pathogenic microbes, which are highly dependent on carbon resources exuded by plant roots. Sugar transport, which is a key process of plant physiology, is essential to support the fate of plant-microbe interactions. During evolution, plants have acquired the ability to perceive microbial molecules, initiating specific signal transduction cascades and leading to adapted response for microbe lifestyles (avirulent, virulent, or benefic). Plant survival will depend on the nature of the induced mechanisms. My PhD work, carried out on a simplified experimental system, contributes to the understanding of mech…
Functional exploration of the stress response in microorganisms of technological interest : dynamics of membrane response after an ethanol shock in S…
2015
The study of membrane response induced by ethanol stress in Saccharomyces cerevisiae aims to understand mechanisms involved in the survival of eukaryotic cells submitted to high ethanol concentrations. The cell membrane by its position between the intra- and extracellular environment is the first target of ethanolic perturbations. Experiments performed in this study aimed to characterize the maintain of the functional integrity of the membrane in relation to the sterol composition in the yeast S. cerevisiae submitted to different types of ethanolic disturbances: increasing concentrations of ethanol in the growth medium; ethanolic shocks of increasing magnitude; shock 20% ethanol for 15 minu…
Estudio de la proteína de membrana de Saccharomyces cerevisiae Rot1: Importancia de su dominio transmembrana
2016
Las proteínas de membranas corresponden a una fracción significativa, entre un 20-30%, del proteoma eucariota y están implicadas en una variedad de funciones celulares. Sin embargo, muchas veces su estudio es complicado, con respecto a sus contrapartes citoplasmáticas, debido principalmente a su naturaleza hidrofóbica. En el presente trabajo se caracterizó a Rot1, una proteína de membrana esencial de Saccharomyces cerevisiae. Esta proteína posee un dominio transmembrana (TM) en su extremo C-terminal necesario tanto para anclarse a la membrana del retículo endoplásmico (RE) como para la función de la proteína, la cual se desconoce, aunque se ha visto relacionada con diferentes procesos celul…