Proceedings of the Natural Academy of Sciences

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  • ERAP1 allotype pairs distinguish AS individuals [Immunology and Inflammation]
    [Dec 2014]

    For more than 40 y, expression of HLA-B27 has been strongly associated with the chronic inflammatory disease Ankylosing Spondylitis (AS); however, the mechanisms underlying this association are still unknown. Single nucleotide polymorphisms within the aminopeptidase endoplasmic reticulum aminopeptidase 1 (ERAP1), which is essential for trimming peptides before they are presented...
    Categories: Journal Articles
  • MACROD2 and tamoxifen resistance [Medical Sciences]
    [Dec 2014]

    Tamoxifen is effective for treating estrogen receptor-alpha (ER) positive breast cancers. However, few molecular mediators of tamoxifen resistance have been elucidated. Here we describe a previously unidentified gene, MACROD2 that confers tamoxifen resistance and estrogen independent growth. We found MACROD2 is amplified and overexpressed in metastatic tamoxifen-resistant tumors. Transgene overexpression...
    Categories: Journal Articles
  • Young capillary vessels rejuvenate aged islets [Medical Sciences]
    [Dec 2014]

    Pancreatic islets secrete hormones that play a key role in regulating blood glucose levels (glycemia). Age-dependent impairment of islet function and concomitant dysregulation of glycemia are major health threats in aged populations. However, the major causes of the age-dependent decline of islet function are still disputed. Here we demonstrate that...
    Categories: Journal Articles
  • Synthetic bioalcohol pathway in a thermophile [Microbiology]
    [Dec 2014]

    Bioethanol production is achieved by only two metabolic pathways and only at moderate temperatures. Herein a fundamentally different synthetic pathway for bioalcohol production at 70 °C was constructed by insertion of the gene for bacterial alcohol dehydrogenase (AdhA) into the archaeon Pyrococcus furiosus. The engineered strain converted glucose to ethanol...
    Categories: Journal Articles
  • BG505 SOSIP selects HIV neutralizing antibodies [Microbiology]
    [Dec 2014]

    Broadly neutralizing antibodies (bnAbs) targeting the trimer apex of HIV envelope are favored candidates for vaccine design and immunotherapy because of their great neutralization breadth and potency. However, methods of isolating bnAbs against this site have been limited by the quaternary nature of the epitope region. Here we report the...
    Categories: Journal Articles
  • Brain-machine interface for eye movements [Neuroscience]
    [Dec 2014]

    A number of studies in tetraplegic humans and healthy nonhuman primates (NHPs) have shown that neuronal activity from reach-related cortical areas can be used to predict reach intentions using brain–machine interfaces (BMIs) and therefore assist tetraplegic patients by controlling external devices (e.g., robotic limbs and computer cursors). However, to our...
    Categories: Journal Articles
  • Nitric oxide mediates GABA transmission [Neuroscience]
    [Dec 2014]

    Recurrent axon collaterals are a major means of communication between spiny projection neurons (SPNs) in the striatum and profoundly affect the function of the basal ganglia. However, little is known about the molecular and cellular mechanisms that underlie this communication. We show that intrastriatal nitric oxide (NO) signaling elevates the...
    Categories: Journal Articles
  • Neuron number variations in the cerebral cortex [Neuroscience]
    [Dec 2014]

    A massive increase in the number of neurons in the cerebral cortex, driving its size to increase by five orders of magnitude, is a key feature of mammalian evolution. Not only are there systematic variations in cerebral cortical architecture across species, but also across spatial axes within a given cortex....
    Categories: Journal Articles
  • Linking brain development, aging, and disease [Neuroscience]
    [Dec 2014]

    Several theories link processes of development and aging in humans. In neuroscience, one model posits for instance that healthy age-related brain degeneration mirrors development, with the areas of the brain thought to develop later also degenerating earlier. However, intrinsic evidence for such a link between healthy aging and development in...
    Categories: Journal Articles
  • Elevated hippocampal resting-state connectivity [Neuroscience]
    [Dec 2014]

    The brain is not idle during rest. Functional MRI (fMRI) studies have identified several resting-state networks, including the default mode network (DMN), which contains a set of cortical regions that interact with a hippocampus (HC) subsystem. Age-related alterations in the functional architecture of the DMN and HC may influence memory...
    Categories: Journal Articles
  • Optimal resource allocation in cellular sensing [Physics]
    [Dec 2014]

    Living cells deploy many resources to sense their environments, including receptors, downstream signaling molecules, time, and fuel. However, it is not known which resources fundamentally limit the precision of sensing, like weak links in a chain, and which can compensate each other, leading to trade-offs between them. We present a...
    Categories: Journal Articles
  • Agonist binding sites of muscle AChR [Physiology]
    [Dec 2014]

    A muscle acetylcholine receptor (AChR) has two neurotransmitter binding sites located in the extracellular domain, at αδ and either αε (adult) or αγ (fetal) subunit interfaces. We used single-channel electrophysiology to measure the effects of mutations of five conserved aromatic residues at each site with regard to their contribution to...
    Categories: Journal Articles
  • RdDM involves SNF2-RING proteins FRG1 and -2 [Plant Biology]
    [Dec 2014]

    DNA methylation in Arabidopsis thaliana is maintained by at least four different enzymes: DNA METHYLTRANSFERASE1 (MET1), CHROMOMETHYLASE3 (CMT3), DOMAINS REARRANGED METHYLTRANSFERASE2 (DRM2), and CHROMOMETHYLASE2 (CMT2). However, DNA methylation is established exclusively by the enzyme DRM2, which acts in the RNA-directed DNA methylation (RdDM) pathway. Some RdDM components belong to gene...
    Categories: Journal Articles
  • GI and ZTL regulate CO stability for flowering [Plant Biology]
    [Dec 2014]

    Many plants measure changes in day length to synchronize their flowering time with appropriate seasons for maximum reproductive success. In Arabidopsis, the day-length–dependent regulation of CONSTANS (CO) protein stability is crucial to induce FLOWERING LOCUS T (FT) expression for flowering in long days. The FLAVIN-BINDING, KELCH REPEAT, F-BOX1 (FKF1) protein...
    Categories: Journal Articles
  • Collapse of cooperation in evolving games [Social Sciences]
    [Dec 2014]

    Game theory provides a quantitative framework for analyzing the behavior of rational agents. The Iterated Prisoner’s Dilemma in particular has become a standard model for studying cooperation and cheating, with cooperation often emerging as a robust outcome in evolving populations. Here we extend evolutionary game theory by allowing players’ payoffs...
    Categories: Journal Articles
  • Correction for Reich et al., Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections [Correction]
    [Dec 2014]

    ECOLOGY Correction for “Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections,” by Peter B. Reich, Roy L. Rich, Ying-Ping Wang, and Jacek Oleksyn, which appeared in issue 38, September 23, 2014, of Proc Natl Acad Sci USA (111:13703–13708; first published September 15, 2014;...
    Categories: Journal Articles
  • Correction for Gao et al., Evidence for multiple roles for grainyheadlike 2 in the establishment and maintenance of human mucociliary airway epithelium [Correction]
    [Dec 2014]

    CELL BIOLOGY Correction for “Evidence for multiple roles for grainyheadlike 2 in the establishment and maintenance of human mucociliary airway epithelium,” by Xia Gao, Christopher M. Vockley, Florencia Pauli, Kimberly M. Newberry, Yan Xue, Scott H. Randell, Timothy E. Reddy, and Brigid L. M. Hogan, which appeared in issue 23,...
    Categories: Journal Articles
  • Correction for Abedini et al., Cell fate regulation by gelsolin in human gynecologic cancers [Correction]
    [Dec 2014]

    CELL BIOLOGY Correction for “Cell fate regulation by gelsolin in human gynecologic cancers,” by Mohammad R. Abedini, Pei-Wen Wang, Yu-Fang Huang, Mingju Cao, Cheng-Yang Chou, Dar-Bin Shieh, and Benjamin K. Tsang, which appeared in issue 40, October 7, 2014, of Proc Natl Acad Sci USA (111:14442–14447; first published September 22,...
    Categories: Journal Articles
  • In This Issue [This Week in PNAS]
    [Dec 2014]

    Chemical gardens in quasi-2D Chemical gardens in confined geometry. When clumps of some solid metal salts are dropped into an anionic solution such as water glass, the salts tend to precipitate into a dazzling array of crystals with tendrils and offshoots that resemble a lush garden. Chemical gardens have long...
    Categories: Journal Articles
  • Gerry Neugebauer: Pioneer of infrared astronomy [Retrospectives]
    [Dec 2014]

    Sometime near the end of 2018, National Aeronautics and Space Administration (NASA) will launch the James Webb Space Telescope (JWST). This “mega” space infrared observatory builds on decades of extremely successful space infrared astronomy missions and infrared instruments for ground-based telescopes that have provided new insights into an otherwise hidden...
    Categories: Journal Articles