2,689 research outputs found

    Regulation of Drosophila Vasa In Vivo through Paralogous Cullin-RING E3 Ligase Specificity Receptors

    Get PDF
    In Drosophila species, molecular asymmetries guiding embryonic development are established maternally. Vasa, a DEAD-box RNA helicase, accumulates in the posterior pole plasm, where it is required for embryonic germ cell specification. Maintenance of Vasa at the posterior pole requires the deubiquitinating enzyme Fat facets, which protects Vasa from degradation. Here, we found that Gustavus (Gus) and Fsn, two ubiquitin Cullin-RING E3 ligase specificity receptors, bind to the same motif on Vasa through their paralogous B30.2/SPRY domains. Both Gus and Fsn accumulate in the pole plasm in a Vasa-dependent manner. Posterior Vasa accumulation is precocious in Fsn mutant oocytes; Fsn overexpression reduces ovarian Vasa levels, and embryos from Fsn-overexpressing females form fewer primordial germ cells (PGCs); thus, Fsn destabilizes Vasa. In contrast, endogenous Gus may promote Vasa activity in the pole plasm, as gus females produce embryos with fewer PGCs, and posterior accumulation of Vas is delayed in gus mutant oocytes that also lack one copy of cullin-5. We propose that Fsn- and Gus-containing E3 ligase complexes contribute to establishing a fine-tuned steady state of Vasa ubiquitination that influences the kinetics of posterior Vasa deployment.open112626sciescopu

    Detection of Heparin in the Salivary Gland and Midgut of Aedes togoi

    Get PDF
    Mosquitoes secrete saliva that contains biological substances, including anticoagulants that counteract a host's hemostatic response and prevent blood clotting during blood feeding. This study aimed to detect heparin, an anticoagulant in Aedes togoi using an immunohistochemical detection method, in the salivary canal, salivary gland, and midgut of male and female mosquitoes. Comparisons showed that female mosquitoes contained higher concentrations of heparin than male mosquitoes. On average, the level of heparin was higher in blood-fed female mosquitoes than in non-blood-fed female mosquitoes. Heparin concentrations were higher in the midgut than in the salivary gland. This indicates presence of heparin in tissues of A. togoi.X111Ysciescopu

    Crystallization and preliminary X-ray crystallographic analysis of SEDL

    Get PDF
    SEDL (known also as sedlin) is a 140 amino-acid protein with a putative role in endoplasmic reticulum-to-Golgi transport. Several missense mutations and deletion mutations in the SEDL gene, which result in protein truncation by frame shift, are responsible for spondyloepiphyseal dysplasia tarda, a progressive skeletal disorder. The protein is identical to MIP-2A, which was shown to interact physically with c-myc promotor-binding protein 1 (MBP-1) and relieve the regulatory role of MBP-1 as a general transcription repressor. In order to gain insights into the function of SEDL by structural analysis, the protein was overexpressed and crystallized as a first step. SEDL was overexpressed in Escherichia coli and crystallized using the hanging-drop vapour-diffusion method at 298 K. The crystals belong to the orthorhombic space group C2221, with unit-cell parameters a = 46.69, b = 101.30, c = 66.15 A. The unit cell is likely to contain one molecule of SEDL, with a crystal volume per protein mass (VM) of 2.36 A3 Da-1 and a solvent content of about 47.9% by volume. A native data set to 2.8 A resolution was obtained from a flash-cooled crystal using synchrotron radiation.open1

    Extreme stiffness hyperbolic elastic metamaterial for total transmission subwavelength imaging

    Get PDF
    Subwavelength imaging by metamaterials and extended work to pursue total transmission has been successfully demonstrated with electromagnetic and acoustic waves very recently. However, no elastic counterpart has been reported because earlier attempts suffer from considerable loss. Here, for the first time, we realize an elastic hyperbolic metamaterial lens and experimentally show total transmission subwavelength imaging with measured wave field inside the metamaterial lens. The main idea is to compensate for the decreased impedance in the perforated elastic metamaterial by utilizing extreme stiffness, which has not been independently actualized in a continuum elastic medium so far. The fabricated elastic lens is capable of directly transferring subwavelength information from the input to the output boundary. In the experiment, this intriguing phenomenon is confirmed by scanning the elastic structures inside the lens with laser scanning vibrometer. The proposed elastic metamaterial lens will bring forth significant guidelines for ultrasonic imaging techniquesope

    Lpg0393 of Legionella pneumophila is a guanine-nucleotide exchange factor for Rab5, Rab21 and Rab22

    Get PDF
    Legionella pneumophila, a human intracellular pathogen, encodes about 290 effector proteins that are translocated into host cells through a secretion machinery. Some of these proteins have been shown to manipulate or subvert cellular processes during infection, but functional roles of a majority of them remain unknown. Lpg0393 is a newly identified Legionella effector classified as a hypothetical protein. Through X-ray crystallographic analysis, we show that Lpg0393 contains a Vps9-like domain, which is structurally most similar to the catalytic core of human Rabex-5 that activates the endosomal Rab proteins Rab5, Rab21 and Rab22. Consistently, Lpg0393 exhibited a guanine-nucleotide exchange factor activity toward the endosomal Rabs. This work identifies the first example of a bacterial guanine-nucleotide exchange factor that is active towards the Rab5 sub-cluster members, implying that the activation of these Rab proteins might be advantageous for the intracellular survival of Legionella

    Smc5/6 coordinates formation and resolution of joint molecules with chromosome morphology to ensure meiotic divisions

    Get PDF
    During meiosis, Structural Maintenance of Chromosome (SMC) complexes underpin two fundamental features of meiosis: homologous recombination and chromosome segregation. While meiotic functions of the cohesin and condensin complexes have been delineated, the role of the third SMC complex, Smc5/6, remains enigmatic. Here we identify specific, essential meiotic functions for the Smc5/6 complex in homologous recombination and the regulation of cohesin. We show that Smc5/6 is enriched at centromeres and cohesin-association sites where it regulates sister-chromatid cohesion and the timely removal of cohesin from chromosomal arms, respectively. Smc5/6 also localizes to recombination hotspots, where it promotes normal formation and resolution of a subset of joint-molecule intermediates. In this regard, Smc5/6 functions independently of the major crossover pathway defined by the MutLγ complex. Furthermore, we show that Smc5/6 is required for stable chromosomal localization of the XPF-family endonuclease, Mus81-Mms4Eme1. Our data suggest that the Smc5/6 complex is required for specific recombination and chromosomal processes throughout meiosis and that in its absence, attempts at cell division with unresolved joint molecules and residual cohesin lead to severe recombination-induced meiotic catastroph

    What are the competences in information system required by managers? Curriculum development for management and public administration degrees

    Get PDF
    [EN] This paper analyzes the competences required by executives to manage information system, and consequently, the competences that must define the information system subjects in non-technical degrees, degrees, such as Public Administration or Business Management. This work reviews the literature about business managers competences on Information Technologies (IT) and compares the theory with the traditional body of knowledge about information systems taught at business schools. By analyzing the executives function, their role in the information system management, and, above, all the importance of their decisions in the effective integration of IT in business processes, this work proposes specific development in seven knowledge areas that facilitate the acquisition of these types of executive competencesDevece Carañana, CA.; Peris-Ortiz, M.; Rueda Armengot, C. (2016). What are the competences in information system required by managers? Curriculum development for management and public administration degrees. Technology, Innovation and Education. 2(10):1-9. doi:10.1186/s40660-016-0016-2S19210Bassellier G, Benbasat I (2004) Business competence of IT professionals: conceptual development and influence on IT-business partnerships. MIS Q 28(4):673–694Bassellier G, Reich BH, Benbasat I (2001) Information technology competence of business managers: a definition and research model. J Manag Inf Syst 17(4):159–182Bassellier G, Benbasat I, Reich BH (2003) The influence of business managers’ IT competence on championing IT. Inf Syst Res 14(4):317–336Bettiol M, Di Maria E, Finotto V (2012) Marketing in SMEs: the role of entrepreneurial sensemaking. Int Entrep Manag J 8(2):223–248Boyatzis RE (1982) The competent manager a model for effective performance. Wiley, New YorkBoynton AC, Zmud RW, Jacobs GC (1994) The influence of IT management practice on IT use in large organizations. MIS Q 18(3):299–318Broadbent M, Weill P (1993) Improving business and information strategy alignment: learning from the banking industry. IBM Syst J 32(1):162–179Brown CV, Magill SL (1994) Alignment of the IS functions with the enterprise: toward a model of antecedents. MIS Q 18(4):371–403Busch EA, Jarvenpaa SL, Tractinsky N, Glick WH (1991) External versus internal perspectives in determining a firm’s progressive use of information technology. Proceedings of the 12th International Conference on Information Systems, New York, 1991:239–250Camisón C (2002) On the relevance of industry, competitive scope, strategic group, size and distinctive competences construct on explaining of organizational performance. Universitat jaume I, Castellón (Working Paper 1–02,Research Group on Strategy, Knowledge Management and Organizational Learning)Castanias RP, Helfat CE (1991) Managerial resources and rents. J Manag 17:155–171Cegarra-Navarro JG, Sánchez-Vidal ME, Cegarra-Leiva D (2011) Balancing exploration and exploitation of knowledge through an unlearning context: an empirical investigation in SMEs. Manag Decis 49(7):1099–1119Chan YE, Reich BH (2007) IT alignment: what have we learned? J Inf Tech 22:297–315Chan YE, Sabherwal R, Thatcher JB (2006) Antecedents and outcomes of strategic IS alignment: an empirical investigation. IEEE Trans Eng Manag 51(3):27–47Croteau AM, Bergeron F (2001) An information technology trilogy: business strategy, technological deployment and organizational performance. J Strateg Inf Syst 10:77–99Crowston K, Myers MD (2004) Information technology and the transformation of industries: three research perspectives. J Strateg Inf Syst 13(1):5–28Dent-Micallef A, Powell T (1998) Technologies de l’information: nécessités stratégiques ou sources d’avantage concurrentiel? Une étude empirique dans le secteur de la distribution aux Etats-Unis. Rev Can Sci Adm 15(1):39–64Devece C (2013) The value of business managers’ ‘information technology’ competence. Serv Ind J 33(7/8):720–733Doll WJ, Torkzadeh G (1987) The relationship of MIS steering committee to size of firm and formalization of mis planning. Commun ACM 30(11):972–978Earl MJ (1996) The risks of outsourcing IT. Sloan Manag Rev 37(3):26–32European Commission (2015) ECTS Users’ Guide 2015. Publications Office of the European Union, Luxembourg. doi: 10.2766/87592Hambrick DC, Brandon G (1988) Executive values. In: Hambrick DC (ed) The executive effect: concepts and methods for studying top managers. JAI Press, GreenwichHambrick DC, Mason PA (1984) Upper echelons: the organization as a reflection of its top managers. Acad Manag Rev 9(2):193–206Hotho S, Champion K (2011) Small businesses in the new creative industries: innovation as a people management challenge. Manag Decis 49(1):29–54Jarvenpaa SL, Ives B (1991) Executive involment and participation in the management of IT. MIS Q 15(2):52–69Lado AA, Wilson MC (1994) Human resource systems and sustained competitive advantage: a competency-based perspective. Acad Manag Rev 19(4):699–727Lado AA, Boyd NG, Wright P (1992) A competency-based model of sustainable competitive advantage: toward a conceptual integration. J Manag 18(1):77–91Lederer AL, Mendelow AL (1988) Information systems planning: top management takes control. Bus Horiz 31(3):73–78Oh W, Pinsonneault A (2007) On the assessment of the strategic value of information technologies: conceptual and analytical approaches. MIS Q 31(2):239–265Osbaldeston M, Barham K (1992) Using management development for competitive advantage. Long Range Plan 25(6):18–24Penrose ET (1959) The theory of the growth of the firm. Basil Blackwell, OxfordReich BH, Benbasat I (1996) Measuring the linkage between business and information technology objectives. MIS Q 20(1):55–81Reich BH, Benbasat I (2000) Factors that influence the social dimension of alignment between business and information techonology objectives. MIS Q 24(1):81–113Riegner C (2007) Word of mouth on the web: the impact of web 2.0 on consumer purchase decisions. J Advert Res 47(4):436–447Rockart JF (1988) The lines takes the leadership. Sloan Manag Rev 29(4):57–64Sabherwal R, Chan YE (2001) Alignment between business and IS strategies: a study of prospectors, analyzers, and defenders. Inf Syst Res 12(1):11–33Sanchez R, Heene A, Thomas H (1996) Towards the theory and practice of competence-based competition. In: Sanchez R, Heene A, Thomas H (eds) Dynamics of competence-based competition: theory and practice in the new strategic management. Elsevier, London, pp 1–35Senge PM (1990) The fifth discipline: the age and practice of the learning organization. Century Business, LondonSiegel DS, Renko M (2012) The role of market and technological knowledge in recognizing entrepreneurial opportunities. Manag Decis 50(5):797–816Stare M, Jaklic A, Kotnik P (2006) Exploiting ICT potential in service firms in transition economies. Serv Ind J 26(3):287–302Swanson EB (1974) Management information systems: appreciation and involvement. Manag Sci 21(2):178–188Torkzadeh G, Xia W (1992) Managing telecommunications by steering committee. MIS Q 16(2):187–199Westley F, Mintzberg H (1989) Visionary leadership and strategic management. Strateg Manag J 10:17–32Yang TT, Li CR (2011) Competence exploration and exploitation in new product development: the moderating effects of environmental dynamism and competitiveness. Manag Decis 49(9):1444–147

    Computational approaches for modeling human intestinal absorption and permeability

    Get PDF
    Human intestinal absorption (HIA) is an important roadblock in the formulation of new drug substances. Computational models are needed for the rapid estimation of this property. The measurements are determined via in vivo experiments or in vitro permeability studies. We present several computational models that are able to predict the absorption of drugs by the human intestine and the permeability through human Caco-2 cells. The training and prediction sets were derived from literature sources and carefully examined to eliminate compounds that are actively transported. We compare our results to models derived by other methods and find that the statistical quality is similar. We believe that models derived from both sources of experimental data would provide greater consistency in predictions. The performance of several QSPR models that we investigated to predict outside the training set for either experimental property clearly indicates that caution should be exercised while applying any of the models for quantitative predictions. However, we are able to show that the qualitative predictions can be obtained with close to a 70% success rate
    corecore