Genetic characterization of the 534DPPR motif of the yeast plasma membrane H+-ATPase

AbstractThe highly conserved motif 534DPPR of Saccharomyces cerevisiae H+-ATPase, located in the putative ATP binding site, has been mutagenized and the resulting 23 mutant genes conditionally expressed in secretory vesicles. Fourteen mutant ATPases (D534A, D534V, D534L, D534N, D534G, D534T, P535A, P535V, P535L, P535G, P535T, P535E, P535K and R537T) failed to reach the secretory vesicles. Of these mutants, nine (D534N, D534T, P535A, P535V, P535L, P535G, P535T, P535E and P535K) were not detected in total cellular membranes, and five (D534A, D534V, D534G, D534L and R537T) were retained at the endoplasmic reticulum and exhibited a dominant lethal phenotype. The remaining mutants (D534E, R537A, R537V, R537L, R537N, R537G, R537E, R537K and R537H) reached the secretory vesicles at levels similar to that of the wild type. Of these, six (R537A, R537V, R537L, R537N, R537G, and R537E) showed severely decreased ATPase activity compared to the wild type enzyme, and three (D534E, R537K and R537H) rendered an enzyme with an altered Km for ATP

Computations on an equation of the Birch and Swinnerton-Dyer type

textLet us assume that E/Q is an elliptic curve of level N and rank equal to 1. Let q be a prime that does not divide the conductor. We study conjecture 4 of B. Mazur and J. Tate in [MT87]. This conjecture relates to the Birch and Swinnerton-Dyer problem in the q-adic case. We produce a lot of numerical evidence towards the conjecture. We also propose a refinement of the conjecture in the rank 1 case in section 2.3.Mathematic

Hijacking of eukaryotic functions by intracellular bacterial pathogens

Intracellular bacterial pathogens have evolved as a group of microorganisms endowed with weapons to hijack many biological processes of eukaryotic cells. This review discusses how these pathogens perturb diverse host cell functions, such as cytoskeleton dynamics and organelle vesicular trafficking. Alteration of the cytoskeleton is discussed in the context of the bacterial entry process (invasion), which occurs either by activation of membrane-located host receptors (“zipper” mechanism) or by injection of bacterial proteins into the host cell cytosol (“trigger” mechanism). In addition, the two major types of intracellular lifestyles, cytosolic versus intravacuolar (phagosomal), which are the consequence of alterations in the phagosome-lysosome maturation route, are compared. Specific examples illustrating known mechanisms of mimicry or hijacking of the host target are provided. Finally, recent advances in phagosome proteomics and genome expression in intracellular bacteria are described. These new technologies are yielding valuable clues as to how these specialized bacterial pathogens manipulate the mammalian host cell. [Int Microbiol 2004; 7(3):181–191

The cell wall integrity/remodeling MAPK cascade is involved in glucose activation of the yeast plasma membrane H+-ATPase

AbstractGlucose triggers transcriptional and post-transcriptional mechanisms that increase the amount and the activity of Saccharomyces cerevisiae plasma membrane H+-ATPase. In a previous study, we found that a mutation in the Rsp5 ubiquitin–protein ligase enzyme affected the post-transcriptional activation of the enzyme by glucose. Mutations at the RSP5 locus alter the glucose-triggered Km decrease. In a genetic screening for multicopy suppressors of the rsp5 mutation, we identified the WSC2/YNL283c gene. Deletion of the WSC2 gene disturbs ATPase activation by glucose, abolishing the Km decrease that occurs during this process. Wsc2 is a component of the PKC1-MPK1 mitogen-activated protein kinase (MAPK) signaling pathway that controls the cell wall integrity. Deletion of the MPK1/SLT2 gene disturbs the glucose-triggered Km decrease in ATPase

Mecanismos cognitivos para el enriquecimiento semántico del discurso mediante funciones de mapeo

En este trabajo estudiamos ciertos mecanismos lingüístico-cognitivos involucrados en los procesos de enriquecimiento semántico del discurso y del diálogo: dislocación de los perfiles de normalidad y fallo del Principio de Extensionalidad, desautomatización de expresiones y estudio inferencial de sus contenidos, y uso de tropos (morfosintácticos y léxico-semánticos). Igualmente, hemos realizado un análisis de la modificación de los perfiles de normalidad y de las zonas activas, así como de la creación de amalgamas conceptuales en dichos procesosIn this paper we study some linguistic-cognitive mechanisms involved in semantic enrichment processes of discourse and dialogue: dislocation of normality profiles and failure of the Extensionality Principle, disautomatization of expressions and inferential study of its contents, and use of tropes (morpho-syntactic and lexical-semantic tropes). We have also analyzed the modification of normality profiles, active zones, and the creation of conceptual blending in these processe

Resilence, rural development and suistainable management: a working with people model approach

Nowadays, it has become evident the need to seek sustainable development models that address challenges arising in a variety of contexts. The resilience concept appears connected to the ability of people to cope with adversities that inevitably arise due to context dynamics, at different spatial and temporal scales. This concept is related to the model known as Working With People (WWP), focused on rural development projects planning, management and evaluation, from the integration of three dimensions: technical-entrepreneurial, ethical-social and political-contextual. The research reported is part of the RETHINK European Project, whose overall aim is farm modernization and rural resilience. The resilience concept has been analyzed, in the scope of rural development projects management, and a relationship with the WWP model has been established. To this end, a thorough review of the scientific literature concerning this topic has been addressed, in order to develop the state of the art of the different concepts and models involved. A conceptual proposal for the integration of resilience in rural development projects sustainable management, through the three-dimensional WWP model is presented

Economic evaluation about different kinds of foundation for the same building

La finalidad de este proyecto es realizar un estudio del impacto que genera el tipo de suelo sobre el que coloquemos un edificio. Para ello se tomarán cuatro suelos de distintas tipologías y características, y se colocará sobre esos suelos un edificio en común entre los cuatro, y esto dará distintas cimentaciones según se comporten las cargar que vienen del edificio sobre el terreno, y una vez obtenido la cimentación que más se adapta a cada suelo se realizará un estudio económico de cada cimentación y el impacto que la elección del suelo genera sobre el coste del edificio completo.Escuela de Arquitectura e Ingeniería de EdificaciónUniversidad Politécnica de Cartagen

A disulfide bond in the membrane protein IgaA is essential for repression of the RcsCDB system

IgaA is an integral inner membrane protein that was discovered as repressor of the RcsCDB phosphorelay system in the intracellular pathogen Salmonella enterica serovar Typhimurium. The RcsCDB system, conserved in many members of the family Enterobacteriaceae, regulates expression of varied processes including motility, biofilm formation, virulence and response to envelope stress. IgaA is an essential protein to which, in response to envelope perturbation, the outer membrane lipoprotein RcsF has been proposed to bind in order to activate the RcsCDB phosphorelay. Envelope stress has also been reported to be sensed by a surface exposed domain of RcsF. These observations support a tight control of the RcsCDB system by RcsF and IgaA via mechanisms that, however, remain unknown. Interestingly, RcsF and IgaA have four conserved cysteine residues in loops exposed to the periplasmic space. Two non-consecutive disulfide bonds were shown to be required for RcsF function. Here, we report mutagenesis studies supporting the presence of one disulfide bond (C404-C425) in the major periplasmic loop of IgaA that is essential for repression of the RcsCDB phosphorelay. Our data therefore suggest that the redox state of the periplasm may be critical for the control of the RcsCDB system by its two upstream regulators, RcsF and IgaA.Work in our laboratory is supported by grants BIO2016-77639-P (AEI/FEDER, UE) and PCIN-2016-082 (to FG-dP) from the Spanish Ministry of Economy and Competitiveness and European Regional Development Funds (FEDER)

Characterization of two second-site mutations preventing wild type protein aggregation caused by a dominant negative PMA1 mutant

The correct biogenesis and localization of Pma1 at the plasma membrane is essential for yeast growth. A subset of PMA1 mutations behave as dominant negative because they produce aberrantly folded proteins that form protein aggregates, which in turn provoke the aggregation of the wild type protein. One approach to understand this dominant negative effect is to identify second-site mutations able to suppress the dominant lethal phenotype caused by those mutant alleles. We isolated and characterized two intragenic second-site suppressors of the PMA1-D378T dominant negative mutation. We present here the analysis of these new mutations that are located along the amino-terminal half of the protein and include a missense mutation, L151F, and an in-frame 12bp deletion that eliminates four residues from Cys409 to Ala412. The results show that the suppressor mutations disrupt the interaction between the mutant and wild type enzymes, and this enables the wild type Pma1 to reach the plasma membraneThis work was supported by the Spanish Ministerio de Ciencia e Innovación Grant BFU2008-0428