Arabidopsis G-protein interactome reveals connections to cell wall carbohydrates and morphogenesis

Yeast two-hybrid technology is used to build a high-quality protein interaction network centered on Arabidopsis G-protein coupled signaling. The interactions uncovered are without precedent in animals and fungi and help identify new cellular roles for G-protein signaling in plants.The heterotrimeric G-protein complex is minimally composed of Gα, Gβ, and Gγ subunits. In the classic scenario, the G-protein complex is the nexus in signaling from the plasma membrane, where the heterotrimeric G-protein associates with heptahelical G-protein-coupled receptors (GPCRs), to cytoplasmic target proteins called effectors. Although a number of effectors are known in metazoans and fungi, none of these are predicted to exist in their canonical forms in plants. To identify ab initio plant G-protein effectors and scaffold proteins, we screened a set of proteins from the G-protein complex using two-hybrid complementation in yeast. After deep and exhaustive interrogation, we detected 544 interactions between 434 proteins, of which 68 highly interconnected proteins form the core G-protein interactome. Within this core, over half of the interactions comprising two-thirds of the nodes were retested and validated as genuine in planta. Co-expression analysis in combination with phenotyping of loss-of-function mutations in a set of core interactome genes revealed a novel role for G-proteins in regulating cell wall modification

Shell size, body mass and average pO2 in mantle cavity water of different marine mollusc species

Marine invertebrates with open circulatory system establish low and constant oxygen partial pressure (Po2) around their tissues. We hypothesized that as a first step towards maintenance of low haemolymph and tissue oxygenation, the Po2 in molluscan mantle cavity water should be lowered against normoxic (21 kPa) seawater Po2, but balanced high enough to meet the energetic requirements in a given species. We recorded Po2 in mantle cavity water of five molluscan species with different lifestyles, two pectinids (Aequipecten opercularis, Pecten maximus), two mud clams (Arctica islandica, Mya arenaria), and a limpet (Patella vulgata). All species maintain mantle cavity water oxygenation below normoxic Po2. Average mantle cavity water Po2 correlates positively with standard metabolic rate (SMR): highest in scallops and lowest in mud clams. Scallops show typical Po2 frequency distribution, with peaks between 3 and 10 kPa, whereas mud clams and limpets maintain mantle water Po2 mostly <5 kPa. Only A. islandica and P. vulgata display distinguishable temporal patterns in Po2 time series. Adjustment of mantle cavity Po2 to lower than ambient levels through controlled pumping prevents high oxygen gradients between bivalve tissues and surrounding fluid, limiting oxygen flux across the body surface. The patterns of Po2 in mantle cavity water correspond to molluscan ecotypes

Javanese Cultural Words in Local Newspapers in Central Java as a Language Maintenance Model

Javanese cultural words are the linguistic units which are very specific to Javanese culture and society. This article aims at describing what Javanese cultural words that are found in the local newspapers, what they represent, and why they are used in the local newspapers in Central Java. Non-participant observation is used to present the data for analysis, continued with page-filing and note-taking techniques. Referential, reflective-introspective, and abductive inferential methods are used to analyze the data. The result indicates that the Javanese cultural words found in the local newspapers represent festivals, rituals, Javanese ways of life, social activities, actions, feelings, thoughts, behavior, and experiences. The words become the indicators that the journalists of the local newspapers in Cental Java have positive attitudes toward Javanese words. This becomes a model for language maintenance of Javanese. This implies that the words are stored in the long-term memory, that become mental image, which are used when needed by the user for communication. The existence of the concepts residing in the mind will make the Javanese language maintenance possible, which is supported by the attitudes of the Javanese

Selektivität und direkte Wirkungen von Vermittlungsgutscheinen: Empirische Befunde aus der Einführungsphase

In April 2002 German government introduced job placement vouchers as a new instrument of active labour market policy to foster the transition of unemployed to jobs. This paper investigates the demand, the treatment effect of the treated and the economic efficiency of job placement vouchers issued from May 2003 to June 2004. The analysis employs a large sample of unemployed individuals from administrative data collected by the German Federal Employment Agency. 20 percent of the West German and 37 percent of the East German unemployed demanded a voucher. According to the microeconometric results the treatment impact of the treated is positive. 5 out of 100 voucher recipients found a job as a result of the instrument. An additional analysis of the cost and returns of the voucher scheme reveals that the return remains positive if no more than 70 per cent of the direct effects are compensated by indirect (substitution) effects. Copyright Verein für Socialpolitik und Blackwell Publishing Ltd. 2006