Proceedings of the Natural Academy of Sciences

Proceedings of the National Academy of Sciences RSS feed -- current issue
  • Winner-take-all phase of synaptic tagging [Neuroscience]
    [Aug 2014]

    Canonical models suggest that mechanisms of long-term memory consist of a synapse-specific, protein synthesis-independent induction phase (changes in synaptic weights/temporary tagging of such synapses) and, within adjacent dendritic compartments, a protein synthesis-dependent distribution phase that may accompany or immediately precede induction and whose protein products enable consolidation through synaptic capture....
    Categories: Journal Articles
  • Mother-to-infant transmission of a specific fear [Neuroscience]
    [Aug 2014]

    Emotional trauma is transmitted across generations. For example, children witnessing their parent expressing fear to specific sounds or images begin to express fear to those cues. Within normal range, this is adaptive, although pathological fear, such as occurs in posttraumatic stress disorder or specific phobias, is also socially transmitted to...
    Categories: Journal Articles
  • Lactate stimulates plasticity gene expression [Neuroscience]
    [Aug 2014]

    l-lactate is a product of aerobic glycolysis that can be used by neurons as an energy substrate. Here we report that in neurons l-lactate stimulates the expression of synaptic plasticity-related genes such as Arc, c-Fos, and Zif268 through a mechanism involving NMDA receptor activity and its downstream signaling cascade Erk1/2....
    Categories: Journal Articles
  • HIV protease dimerization occurs through two steps [Pharmacology]
    [Aug 2014]

    Dimerization of HIV-1 protease (PR) subunits is an essential process for PR’s acquisition of proteolytic activity, which plays a critical role in the maturation of HIV-1. Recombinant wild-type PR (PRWT) proved to dimerize, as examined with electrospray ionization mass spectrometry; however, two active site interface PR mutants (PRT26A and PRR87K)...
    Categories: Journal Articles
  • JP2 overexpression protects against heart failure [Physiology]
    [Aug 2014]

    Heart failure is accompanied by a loss of the orderly disposition of transverse (T)-tubules and a decrease of their associations with the junctional sarcoplasmic reticulum (jSR). Junctophilin-2 (JP2) is a structural protein responsible for jSR/T-tubule docking. Animal models of cardiac stresses demonstrate that down-regulation of JP2 contributes to T-tubule disorganization,...
    Categories: Journal Articles
  • CCD2 starts the saffron crocin biosynthesis [Plant Biology]
    [Aug 2014]

    Crocus sativus stigmas are the source of the saffron spice and accumulate the apocarotenoids crocetin, crocins, picrocrocin, and safranal, responsible for its color, taste, and aroma. Through deep transcriptome sequencing, we identified a novel dioxygenase, carotenoid cleavage dioxygenase 2 (CCD2), expressed early during stigma development and closely related to, but...
    Categories: Journal Articles
  • Oxytocin biology, social functioning, and autism [Psychological and Cognitive Sciences]
    [Aug 2014]

    The neuropeptide oxytocin (OXT) and its receptor (OXTR) regulate social functioning in animals and humans. Initial clinical research suggests that dysregulated plasma OXT concentrations and/or OXTR SNPs may be biomarkers of social impairments in autism spectrum disorder (ASD). We do not know, however, whether OXT dysregulation is unique to ASD...
    Categories: Journal Articles
  • A computational and neural model of happiness [Psychological and Cognitive Sciences]
    [Aug 2014]

    The subjective well-being or happiness of individuals is an important metric for societies. Although happiness is influenced by life circumstances and population demographics such as wealth, we know little about how the cumulative influence of daily life events are aggregated into subjective feelings. Using computational modeling, we show that emotional...
    Categories: Journal Articles
  • lncRNAs in the mouse heart [Systems Biology]
    [Aug 2014]

    The vast majority of mammalian DNA does not encode for proteins but instead is transcribed into noncoding (nc)RNAs having diverse regulatory functions. The poorly characterized subclass of long ncRNAs (lncRNAs) can epigenetically regulate protein-coding genes by interacting locally in cis or distally in trans. A few reports have implicated specific...
    Categories: Journal Articles
  • Retraction for Schlaberg et al., XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors [Retractions]
    [Aug 2014]

    MEDICAL SCIENCES Retraction for “XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors,” by Robert Schlaberg, Daniel J. Choe, Kristy R. Brown, Harshwardhan M. Thaker, and Ila R. Singh, which appeared in issue 38, September 22, 2009, of Proc Natl Acad Sci USA...
    Categories: Journal Articles
  • Targeted delivery of IL4 cures mice with arthritis [Applied Biological Sciences]
    [Aug 2014]

    Antibody–cytokine fusion proteins (immunocytokines) are innovative biopharmaceutical agents, which are being considered for the therapy of cancer and chronic inflammatory conditions. Immunomodulatory fusion proteins capable of selective localization at the sites of rheumatoid arthritis (RA) are of particular interest, as they may increase the therapeutic index of the cytokine payload....
    Categories: Journal Articles
  • Biological lignin funneling [Applied Biological Sciences]
    [Aug 2014]

    Lignin is an energy-dense, heterogeneous polymer comprised of phenylpropanoid monomers used by plants for structure, water transport, and defense, and it is the second most abundant biopolymer on Earth after cellulose. In production of fuels and chemicals from biomass, lignin is typically underused as a feedstock and burned for process...
    Categories: Journal Articles
  • Disassembly of mitotic checkpoint complexes [Biochemistry]
    [Aug 2014]

    The mitotic (or spindle assembly) checkpoint system delays anaphase until all chromosomes are correctly attached to the mitotic spindle. When the checkpoint is active, a Mitotic Checkpoint Complex (MCC) assembles and inhibits the ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C). MCC is composed of the checkpoint proteins Mad2, BubR1, and Bub3 associated...
    Categories: Journal Articles
  • RNA structure recognition by IFIT5 [Biochemistry]
    [Aug 2014]

    Interferon (IFN) responses play key roles in cellular defense against pathogens. Highly expressed IFN-induced proteins with tetratricopeptide repeats (IFITs) are proposed to function as RNA binding proteins, but the RNA binding and discrimination specificities of IFIT proteins remain unclear. Here we show that human IFIT5 has comparable affinity for RNAs...
    Categories: Journal Articles
  • Automated structure determination of RiPPs [Biochemistry]
    [Aug 2014]

    Ribosomally synthesized and posttranslationally modified peptides (RiPPs) are a growing class of natural products that are found in all domains of life. These compounds possess vast structural diversity and have a wide range of biological activities, promising a fertile ground for exploring novel natural products. One challenging aspect of RiPP...
    Categories: Journal Articles
  • Cooperativity in SNARE-mediated membrane fusion [Biochemistry]
    [Aug 2014]

    The soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complex drives the majority of intracellular and exocytic membrane fusion events. Whether and how SNAREs cooperate to mediate fusion has been a subject of intense study, with estimates ranging from a single SNARE complex to 15. Here we show that there is...
    Categories: Journal Articles
  • Circadian rhythm of Prx hyperoxidation in RBCs [Biochemistry]
    [Aug 2014]

    The catalytic cysteine of the typical 2-Cys Prx subfamily of peroxiredoxins is occasionally hyperoxidized to cysteine sulfinic acid during the peroxidase catalytic cycle. Sulfinic Prx (Prx–SO2H) is reduced back to the active form of the enzyme by sulfiredoxin. The abundance of Prx–SO2H was recently shown to oscillate with a period...
    Categories: Journal Articles
  • Order-disorder in hemagglutinin rearrangement [Biophysics and Computational Biology]
    [Aug 2014]

    Influenza hemagglutinin (HA), a homotrimeric glycoprotein crucial for membrane fusion, undergoes a large-scale structural rearrangement during viral invasion. X-ray crystallography has shown that the pre- and postfusion configurations of HA2, the membrane-fusion subunit of HA, have disparate secondary, tertiary, and quaternary structures, where some regions are displaced by more than...
    Categories: Journal Articles
  • Ligand binding and allostery in the KIX system [Biophysics and Computational Biology]
    [Aug 2014]

    The kinase-inducible domain interacting (KIX) domain of CREB binding protein binds to multiple intrinsically disordered transcription factors in vivo at two distinct sites on its surface. Several reports have been made of allosteric communication between these two sites in this well-characterized model system. In this work, we have performed fluorescence...
    Categories: Journal Articles
  • Defining allosteric effects in KIX complexes [Biophysics and Computational Biology]
    [Aug 2014]

    Allosteric binding events play a critical role in the formation and stability of transcriptional activator–coactivator complexes, perhaps in part due to the often intrinsically disordered nature of one or more of the constituent partners. The kinase-inducible domain interacting (KIX) domain of the master coactivator CREB binding protein/p300 is a conformationally...
    Categories: Journal Articles