Kinetics and subcellular distribution of S35-taurine uptake in rat cerebral cortex slices

Zusammenfassung Die Kinetik der Aufnahme von S³⁵-Taurin in Rattencortex-Schnittchen wird im Konzentrationsbereich von 9×10^–8 M bis 5×10^–3 M untersucht. Nach Abzug des Transportes durch Diffusion (K _D ×S) findet man einen Mechanismus, der Michaelis-Menten Kinetik folgt (v _sat ), mitK _m =1,73×10^–4 M. Ein solcher Transport liegt nicht im Bereich des spezifischen «uptake» der Neurotransmitter. Auch die sehr niedrige Aufnahme-Rate und die subzelluläre Verteilung nach «uptake» sprechen gegen eine Neurotransmitter-Funktion von Taurin.     

Die Konstitution des Phthalylharnstoffs

Summary On the basis of experimental evidence, it is proved that phthalyl urea has the structure II, and not structure I, proposed byPiutti and generally accepted by other investigators.     

Phytochrome signalling is mediated through nucleoside diphosphate kinase 2.

Because plants are sessile, they have developed intricate strategies to adapt to changing environmental variables, including light. Their growth and development, from germination to flowering, is critically influenced by light, particularly at red (660 nm) and far-red (730 nm) wavelengths. Higher plants perceive red and far-red light by means of specific light sensors called phytochromes(A-E). However, very little is known about how light signals are transduced to elicit responses in plants. Here we report that nucleoside diphosphate kinase 2 (NDPK2) is an upstream component in the phytochrome signalling pathway in the plant Arabidopsis thaliana. In animal and human cells, NDPK acts as a tumour suppressor. We show that recombinant NDPK2 in Arabidopsis preferentially binds to the red-light-activated form of phytochrome in vitro and that this interaction increases the activity of recombinant NDPK2. Furthermore, a mutant lacking NDPK2 showed a partial defect in responses to both red and farred light, including cotyledon opening and greening. These results indicate that NDPK2 is a positive signalling component of the phytochrome-mediated light-signal-transduction pathway in Arabidopsis.     

Introducing the Euro Area‐wide Leading Indicator (ALI): Real‐Time Signals of Turning Points in the Growth Cycle from 2007 to 2011

This paper introduces a new monthly euro Area‐wide Leading Indicator (ALI) for the euro area growth cycle which is composed of nine leading series and derived from a one‐sided bandpass filter. The main findings are that (i) the GDP growth cycle in the euro area can be well tracked, in a timely manner and at monthly frequency, by a reference growth cycle indicator (GCI) derived from industrial production excluding construction, (ii) the ALI reliably leads turning points in the GCI by 5 months and (iii) longer leading components of the ALI are good predictors of the GCI up to 9 months ahead. A real‐time case study on the ALI's capabilities for signalling turning points in the euro area growth cycle from 2007 to 2011 confirms these findings. Copyright © 2013 John Wiley & Sons, Ltd.     

Preparing the lethal hit: interplay between exo- and endocytic pathways in cytotoxic T lymphocytes

Cytotoxic T lymphocytes patrol our body in search for infected cells which they kill through the release of cytotoxic substances contained in cytotoxic granules. The fusion of cytotoxic granules occurs at a specially formed contact site, the immunological synapse, and is tightly controlled to ensure specificity. In this review, we discuss the contribution of two intracellular compartments, endosomes and cytotoxic granules, to the formation, function and disassembly of the immunological synapse. We highlight a recently proposed sequential process of fusion events at the IS upon target cell recognition. First, recycling endosomes fuse with the plasma membrane to deliver cargo required for the docking of cytotoxic granules. Second, cytotoxic granules arrive and fuse upon docking in a SNARE-dependent manner. Following fusion, membrane components of the cytotoxic granule are retrieved through endocytosis to ensure the fast, efficient serial killing of target cells that is characteristic of cytotoxic T lymphocytes.     

A survey of human leukaemias for sequences of a human retrovirus

Human T-cell leukaemia-lymphoma virus (HTLV) is an exogenous human retrovirus distinct from all known animal retroviruses. HTLV is closely linked to a subtype of adult T-cell malignancies and except for isolated cases, has not been found associated with any other form of leukaemia, lymphoma or other cancers (see refs 1, 2 for review). HTLV can be transmitted to cord blood T lymphocytes in vitro and the infected cells exhibit characteristics of transformed neoplastic T cells. We have recently cloned DNA sequences derived from approximately 1 kilobase (kb) of the 5' and 3' termini of the HTLV genome, as well as a 4-5-kb defective HTLV provirus flanked by cellular sequences. The availability of these probes has enabled us to carry out a limited survey of different fresh or cultured cells from patients of different lymphoid and myeloid malignancies for HTLV-related DNA sequences. The results presented here show that cells from all Japanese patients with adult T-cell leukaemia and several patients with various mature T-cell malignancies from elsewhere contained one or more copies of a highly conserved HTLV genome. The infected cells are of clonal origin. Fresh cells from 1 of the 10 myeloid leukaemic patients contained exogenous DNA sequences distantly related to HTLV.     

A cytosolic catalase is needed to extend adult lifespan in C. elegans daf-C and clk-1 mutants.

The dauer larva is an alternative larval stage in Caenorhabditis elegans which allows animals to survive through periods of low food availability. Well-fed worms live for about three weeks, but dauer larvae can live for at least two months without affecting post-dauer lifespan. Mutations in daf-2 and age-1, which produce a dauer constitutive (Daf-C) phenotype, and in clk-1, which are believed to slow metabolism, markedly increase adult lifespan. Here we show that a ctl-1 mutation reduces adult lifespan in otherwise wild-type animals and eliminates the daf-c and clk-1-mediated extension of adult lifespan. ctl-1 encodes an unusual cytosolic catalase; a second gene, ctl-2, encodes a peroxisomal catalase. ctl-1 messenger RNA is increased in dauer larvae and adults with the daf-c mutations. We suggest that the ctl-1 catalase is needed during periods of starvation, as in the dauer larva, and that its misexpression in daf-c and clk-1 adults extends lifespan. Cytosolic catalase may have evolved to protect nematodes from oxidative damage produced during prolonged dormancy before reproductive maturity, or it may represent a general mechanism for permitting organisms to cope with the metabolic changes that accompany starvation.