DNA bending facilitates the error-free DNA damage tolerance pathway and upholds genome integrity

Abstract DNA replication is sensitive to damage in the template. To bypass lesions and complete replication, cells activate recombination-mediated (error-free) and translesion synthesis-mediated (error-prone) DNA damage tolerance pathways. Crucial for error-free DNA damage tolerance is template switching, which depends on the formation and resolution of damage-bypass intermediates consisting of sister chromatid junctions. Here we show that a chromatin architectural pathway involving the high mobility group box protein Hmo1 channels replication-associated lesions into the error-free DNA damage tolerance pathway mediated by Rad5 and PCNA polyubiquitylation, while preventing mutagenic bypass and toxic recombination. In the process of template switching, Hmo1 also promotes sister chromatid junction formation predominantly during replication. Its C-terminal tail, implicated in chromatin bending, facilitates the formation of catenations/hemicatenations and mediates the roles of Hmo1 in DNA damage tolerance pathway choice and sister chromatid junction formation. Together, the results suggest that replication-associated topological changes involving the molecular DNA bender, Hmo1, set the stage for dedicated repair reactions that limit errors during replication and impact on genome stability

A novel proviral clone of HIV-2: Biological and phylogenetic relationship to other primate immunodeficiency viruses.

Infectious molecular clones of the human immunodeficiency virus type 2 (HIV-2) will be valuable tools for the study of regulatory gene functions and the development of an animal model for the human acquired immunodeficiency syndrome (AIDS). To this end, we have cloned and sequenced a novel HIV-2 isolate, HIV-2BEN. One clone, designated MK6, is infectious for various human T-cell lines and for human and macaque peripheral blood lymphocytes (PBL), allowing molecular studies of HIV-2 infection and replication. Since MK6 is highly cytopathic in MT-2 and Molt-4 clone 8 cells, antiviral agents and neutralizing sera may be tested. Cluster analysis of HIV-1, HIV-2, and simian immunodeficiency virus (SIV) env and gag genes revealed that HIV-2BEN yielded the earliest node of phylogenetic divergence for all reported HIV-2 sequences. Noise analysis showed that, with the current data, no specification of any branching order can be made among the four groups of primate lentiviruses, HIV-1, HIV-2/SIVSMM/MAC, SIVAGM, and SIVMND

Effects of asenapine, olanzapine, and risperidone on psychotomimetic-induced reversal-learning deficits in the rat

YesBackground: Asenapine is a new pharmacological agent for the acute treatment of schizophrenia and bipolar disorder. It has relatively higher affinity for serotonergic and α2-adrenergic than dopaminergic D2 receptors. We evaluated the effects of asenapine, risperidone, and olanzapine on acute and subchronic psychotomimetic-induced disruption of cued reversal learning in rats. Methods: After operant training, rats were treated acutely with D-amphetamine (0.75 mg/kg intraperitoneally [i.p.]) or phencyclidine (PCP; 1.5 mg/kg i.p.) or sub-chronically with PCP (2 mg/kg i.p. for 7 days). We assessed the effects of acute coadministration of asenapine, risperidone, or olanzapine on acute D-amphetamine– and PCP-induced deficits and the effects of long-term coadministration of these agents (for 28 additional days) on the deficits induced by subchronic PCP. Results: Deficits in reversal learning induced by acute D-amphetamine were attenuated by risperidone (0.2 mg/kg i.p.). Acute PCP-induced impairment of reversal learning was attenuated by acute asenapine (0.025 mg/kg subcutaneously [s.c.]), risperidone (0.2 mg/kg i.p.), and olanzapine (1.0 mg/kg i.p.). Subchronic PCP administration induced an enduring deficit that was attenuated by acute asenapine (0.075 mg/kg s.c.) and by olanzapine (1.5 mg/kg i.p.). Asenapine (0.075 mg/kg s.c.), risperidone (0.2 mg/kg i.p.), and olanzapine (1.0 mg/kg i.p.) all showed sustained efficacy with chronic (29 d) treatment to improve subchronic PCP-induced impairments. Conclusion: These data suggest that asenapine may have beneficial effects in the treatment of cognitive symptoms in schizophrenia. However, this remains to be validated by further clinical evaluation.This research was supported by Schering-Plough Corporation, now Merck & Co., Inc. and Pfizer Inc

The selectivity, voltage-dependence and acid sensitivity of the tandem pore potassium channel TASK-1 : contributions of the pore domains

We have investigated the contribution to ionic selectivity of residues in the selectivity filter and pore helices of the P1 and P2 domains in the acid sensitive potassium channel TASK-1. We used site directed mutagenesis and electrophysiological studies, assisted by structural models built through computational methods. We have measured selectivity in channels expressed in Xenopus oocytes, using voltage clamp to measure shifts in reversal potential and current amplitudes when Rb+ or Na+ replaced extracellular K+. Both P1 and P2 contribute to selectivity, and most mutations, including mutation of residues in the triplets GYG and GFG in P1 and P2, made channels nonselective. We interpret the effects of these—and of other mutations—in terms of the way the pore is likely to be stabilised structurally. We show also that residues in the outer pore mouth contribute to selectivity in TASK-1. Mutations resulting in loss of selectivity (e.g. I94S, G95A) were associated with slowing of the response of channels to depolarisation. More important physiologically, pH sensitivity is also lost or altered by such mutations. Mutations that retained selectivity (e.g. I94L, I94V) also retained their response to acidification. It is likely that responses both to voltage and pH changes involve gating at the selectivity filter

Slx8 removes Pli1-dependent protein-SUMO conjugates including SUMOylated Topoisomerase I to promote genome stability

Peer reviewedPublisher PD

Sensitivity to differences in the motor origin of drawings:from human to robot

This study explores the idea that an observer is sensitive to differences in the static traces of drawings that are due to differences in motor origin. In particular, our aim was to test if an observer is able to discriminate between drawings made by a robot and by a human in the case where the drawings contain salient kinematic cues for discrimination and in the case where the drawings only contain more subtle kinematic cues. We hypothesized that participants would be able to correctly attribute the drawing to a human or a robot origin when salient kinematic cues are present. In addition, our study shows that observers are also able to detect the producer behind the drawings in the absence of these salient kinematic cues. The design was such that in the absence of salient kinematic cues, the drawings are visually very similar, i.e. only differing in subtle kinematic differences. Observers thus had to rely on these subtle kinematic differences in the line trajectories between drawings. However, not only motor origin (human versus robot) but also motor style (natural versus mechanic) plays a role in attributing a drawing to the correct producer, because participants scored less high when the human hand draws in a relatively mechanical way. Overall, this study suggests that observers are sensitive to subtle kinematic differences between visually similar marks in drawings that have a different motor origin. We offer some possible interpretations inspired by the idea of "motor resonance''

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Attraction of the Invasive Halyomorpha halys (Hemiptera: Pentatomidae) to Traps Baited with Semiochemical Stimuli Across the United States

A recent identification of the two-component aggregation pheromone of the invasive stink bug species, Halyomorpha halys (Stål), in association with a synergist, has greatly improved the ability to accurately monitor the seasonal abundance and distribution of this destructive pest. We evaluated the attraction of H. halys to black pyramid traps baited with lures containing the pheromone alone, the synergist methyl (2E,4E,6Z)-decatrienoate (MDT) alone, and the two lures in combination. Traps were deployed around areas of agricultural production including fruit orchards, vegetables, ornamentals, or row crops in Delaware, Maryland, North Carolina, New Jersey, New York, Ohio, Oregon, Pennsylvania, Virginia, and West Virginia from mid-April to mid-October, 2012 and 2013. We confirmed that H. halys adults and nymphs are attracted to the aggregation pheromone season long, but that attraction is significantly increased with the addition of the synergist MDT. H. halys adults were detected in April with peak captures of overwintering adults in mid- to late May. The largest adult captures were late in the summer, typically in early September. Nymphal captures began in late May and continued season long. Total captures declined rapidly in autumn and ceased by mid-October. Captures were greatest at locations in the Eastern Inland region, followed by those in the Eastern Coastal Plain and Pacific Northwest. Importantly, regardless of location in the United States, all mobile life stages of H. halys consistently responded to the combination of H. halys aggregation pheromone and the synergist throughout the entire season, suggesting that these stimuli will be useful tools to monitor for H. halys in managed system