Proceedings of the Natural Academy of Sciences

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  • Mapping only some languages [Physical Sciences]
    [Apr 2015]

    Ronen et al. (1) raise an intriguing question concerning how to define quantitatively “the global influence of languages.” Unfortunately, the limitations and flaws in their datasets raise questions concerning the validity of their maps of global language networks. UNESCO’s Index Translationum (2) project is a wonderful database source for Ronen...
    Categories: Journal Articles
  • When methods matter [Physical Sciences]
    [Apr 2015]

    We appreciate Biersteker’s comments (1) on our research (2). Moreover, we agree with many of her points so wholeheartedly that our paper addresses them in detail: We devote whole sections in the main text and supporting information to the incompleteness of the Index Translationum, the imperfect quality of the language...
    Categories: Journal Articles
  • ERAP1 biology in Ankylosing Spondylitis [Biological Sciences]
    [Apr 2015]

    We read with interest the work of Reeves et al. on endoplasmic reticulum aminopeptidase 1 (ERAP1) haplotypes found in Ankylosing Spondylitis (AS), and have several concerns about the study and its conclusions (1). Reeves et al. (1) claim, on the basis of sequence data from 19 cases and 17 controls,...
    Categories: Journal Articles
  • ERAP1 allotypes and AS [Biological Sciences]
    [Apr 2015]

    We would like to thank Robinson and Brown (1) for their interest in our work (2). In their comments, the authors suggest that the comparison of endoplasmic reticulum aminopeptidase 1 (ERAP1) allotypes in Ankylosing Spondylitis (AS) cases and controls are not statistically different, and therefore do not support the conclusions...
    Categories: Journal Articles
  • Continental crust beneath Iceland [Earth, Atmospheric, and Planetary Sciences]
    [Apr 2015]

    The magmatic activity (0–16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from...
    Categories: Journal Articles
  • Eluding catastrophic shifts [Physics]
    [Apr 2015]

    Transitions between regimes with radically different properties are ubiquitous in nature. Such transitions can occur either smoothly or in an abrupt and catastrophic fashion. Important examples of the latter can be found in ecology, climate sciences, and economics, to name a few, where regime shifts have catastrophic consequences that are...
    Categories: Journal Articles
  • Chiral structures from achiral liquid crystals [Physics]
    [Apr 2015]

    We study chiral symmetry-broken configurations of nematic liquid crystals (LCs) confined to cylindrical capillaries with homeotropic anchoring on the cylinder walls (i.e., perpendicular surface alignment). Interestingly, achiral nematic LCs with comparatively small twist elastic moduli relieve bend and splay deformations by introducing twist deformations. In the resulting twisted and escaped...
    Categories: Journal Articles
  • Prokaryotic minus end-tracking system [Biochemistry]
    [Apr 2015]

    Segregation of DNA is a fundamental process during cell division. The mechanism of prokaryotic DNA segregation is largely unknown, but several low-copy-number plasmids encode cytomotive filament systems of the actin type and tubulin type important for plasmid inheritance. Of these cytomotive filaments, only actin-like systems are mechanistically well characterized. In...
    Categories: Journal Articles
  • Mechanism of atlastin function [Cell Biology]
    [Apr 2015]

    Atlastin (ATL), a membrane-anchored GTPase that mediates homotypic fusion of endoplasmic reticulum (ER) membranes, is required for formation of the tubular network of the peripheral ER. How exactly ATL mediates membrane fusion is only poorly understood. Here we show that fusion is preceded by the transient tethering of ATL-containing vesicles...
    Categories: Journal Articles
  • ISL1 specifies the identity of POMC neurons [Developmental Biology]
    [Apr 2015]

    Food intake and body weight regulation depend on proper expression of the proopiomelanocortin gene (Pomc) in a group of neurons located in the mediobasal hypothalamus of all vertebrates. These neurons release POMC-encoded melanocortins, which are potent anorexigenic neuropeptides, and their absence from mice or humans leads to hyperphagia and severe...
    Categories: Journal Articles
  • Phospholipase C and juvenile hormone signaling [Developmental Biology]
    [Apr 2015]

    Juvenile hormone (JH) is a key regulator of a wide diversity of developmental and physiological events in insects. Although the intracellular JH receptor methoprene-tolerant protein (MET) functions in the nucleus as a transcriptional activator for specific JH-regulated genes, some JH responses are mediated by signaling pathways that are initiated by...
    Categories: Journal Articles
  • Mre11 toxicity in the absence of Sae2 [Genetics]
    [Apr 2015]

    The Mre11–Rad50–Xrs2/NBS1 (MRX/N) nuclease/ATPase complex plays structural and catalytic roles in the repair of DNA double-strand breaks (DSBs) and is the DNA damage sensor for Tel1/ATM kinase activation. Saccharomyces cerevisiae Sae2 can function with MRX to initiate 5′-3′ end resection and also plays an important role in attenuation of DNA...
    Categories: Journal Articles
  • hnRNPLL rewires transcriptome of plasma cells [Immunology and Inflammation]
    [Apr 2015]

    Posttranscriptional regulation is a major mechanism to rewire transcriptomes during differentiation. Heterogeneous nuclear RNA-binding protein LL (hnRNPLL) is specifically induced in terminally differentiated lymphocytes, including effector T cells and plasma cells. To study the molecular functions of hnRNPLL at a genome-wide level, we identified hnRNPLL RNA targets and binding sites...
    Categories: Journal Articles
  • {alpha}IIb{beta}3 variants defined by NGS [Medical Sciences]
    [Apr 2015]

    Next-generation sequencing is transforming our understanding of human genetic variation but assessing the functional impact of novel variants presents challenges. We analyzed missense variants in the integrin αIIbβ3 receptor subunit genes ITGA2B and ITGB3 identified by whole-exome or -genome sequencing in the ThromboGenomics project, comprising ∼32,000 alleles from 16,108 individuals....
    Categories: Journal Articles
  • Membrane curvature-mediated localization of SpoVM [Microbiology]
    [Apr 2015]

    In bacteria, certain shape-sensing proteins localize to differently curved membranes. During sporulation in Bacillus subtilis, the only convex (positively curved) surface in the cell is the forespore, an approximately spherical internal organelle. Previously, we demonstrated that SpoVM localizes to the forespore by preferentially adsorbing onto slightly convex membranes. Here, we...
    Categories: Journal Articles
  • Circadian control of metabolism in S. elongatus [Microbiology]
    [Apr 2015]

    Synechococcus elongatus PCC 7942 is a genetically tractable model cyanobacterium that has been engineered to produce industrially relevant biomolecules and is the best-studied model for a prokaryotic circadian clock. However, the organism is commonly grown in continuous light in the laboratory, and data on metabolic processes under diurnal conditions are...
    Categories: Journal Articles
  • {alpha}-Synuclein directs microglial migration [Neuroscience]
    [Apr 2015]

    Malformed α-Synuclein (α-syn) aggregates in neurons are released into the extracellular space, activating microglia to induce chronic neuroinflammation that further enhances neuronal damage in α-synucleinopathies, such as Parkinson’s disease. The mechanisms by which α-syn aggregates activate and recruit microglia remain unclear, however. Here we show that α-syn aggregates act as...
    Categories: Journal Articles
  • SOX2 primes the epigenetic landscape in NPCs [Neuroscience]
    [Apr 2015]

    Newborn granule neurons generated from neural progenitor cells (NPCs) in the adult hippocampus play a key role in spatial learning and pattern separation. However, the molecular mechanisms that control activation of their neurogenic program remain poorly understood. Here, we report a novel function for the pluripotency factor sex-determining region Y...
    Categories: Journal Articles
  • Transmembrane targeting of dopamine progenitors [Neuroscience]
    [Apr 2015]

    An important challenge for the continued development of cell therapy for Parkinson’s disease (PD) is the establishment of procedures that better standardize cell preparations for use in transplantation. Although cell sorting has been an anticipated strategy, its application has been limited by lack of knowledge regarding transmembrane proteins that can...
    Categories: Journal Articles
  • Role of tectum in command of gaze selection [Neuroscience]
    [Apr 2015]

    The optic tectum (called superior colliculus in mammals) is critical for eye–head gaze shifts as we navigate in the terrain and need to adapt our movements to the visual scene. The neuronal mechanisms underlying the tectal contribution to stimulus selection and gaze reorientation remains, however, unclear at the microcircuit level....
    Categories: Journal Articles