Editors' Choice

Science  14 Aug 2015:
Vol. 349, Issue 6249, pp. 702
  1. Heart Development

    The way to a broken heart

    1. Stella M. Hurtley

    One cell division too many can compromise heart function

    ILLUSTRATION: SCIENCE PICTURE CO/SCIENCE SOURCE

    Mice lacking cardiac myosin binding protein C (MYBC) develop defective hearts that are twice the normal size. MYBC is a component of contractile thick filaments in the cardiac muscle. Jiang et al. found that the heart cells in mice lacking MYBC divided one extra time shortly after birth—when normal mouse heart cells would have stopped dividing. This caused the mice to have more myocytes with single nuclei—which compromise heart function. This unanticipated role of a structural protein in regulating how muscle cells divide may be important in different types of cardiomyopathy in human patients.

    Proc. Natl. Acad. Sci. U.S.A. 112, 9046 (2015).

  2. Neuroscience

    Out-of-register axons control output

    1. Lisa D. Chong

    A neuron integrates synaptic inputs and fires action potentials from its axon initial segment (AIS), a specialized membrane region on neuronal axons that also forms synapses with other axons. Stimulating neurons chronically can cause the AIS to move distally along the axon, but do its associated synapses move with it? To find out, Wefelmeyer et al. used optogenetics and imaging to show that in the rat hippocampus, synapses of chandelier interneurons on pyramidal neurons do not move with the AIS. Nor is there a change in the number of synapses or their architecture. Computational modeling revealed that neurons with distal AIS and proximal synapses have weaker and delayed action potentials. Such AIS plasticity may be a homeostatic mechanism for neurons to avoid becoming overexcited.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1502902112 (2015).

  3. Neuroscience

    Connecting β-amyloid, memory, and sleep

    1. Laura Schuhmacher

    One of the risk factors for developing Alzheimer's disease is poor sleep quality. People consolidate memories while they sleep, suggesting how disrupted sleep could contribute to the cognitive decline seen in individuals with Alzheimer's disease. Mander et al. scanned the brains of healthy older adults for the presence of β-amyloid (Aβ), which is elevated in Alzheimer's disease, and found that it correlated with poor non–rapid eye movement slow-wave sleep quality. They then performed memory retention tests before and after sleep and found that subjects consolidated memories more poorly after a bad night of sleep. A computational model based on these findings suggests that Aβ disrupts people's ability to form memories through its detrimental effects on sleep.

    Nat. Neurosci. 7, 1051 (2015).

  4. Physics

    A qubit keeping cool in a hot environment

    1. Jelena Stajic

    Interactions with a hot environment can cause a qubit—the building block of a quantum computer—to lose the information it is encoding. Now, Bahri et al. show theoretically that adding disorder and topology to the mix can save the day. The authors studied a chain of disordered, interacting spins with topologically protected edge states. The disorder in the chain caused the bulk to become localized. As a consequence, the two edge spins—which acted like qubits—effectively decoupled from the hot bulk. The calculations predicted that such a qubit would retain its information content over a period that grows with the system size.

    Nat. Commun. 10.1038/ncomms8341 (2015).

  5. Extreme Weather

    After pollution, the deluge

    1. H. Jesse Smith
    PHOTO: © DAVID NOTON PHOTOGRAPHY/ALAMY

    Air pollution is mostly thought of as a health hazard but it also can have a major influence on weather. Fan et al. describe a case in the mountainous area northwest of the Sichuan Basin, China, in which heavy air pollution trapped in the basin amplified the rainfall intensity during a storm in the summer of 2013. The authors conclude that aerosols suppressed atmospheric convection by absorbing solar energy and increasing atmospheric stability during daytime, thus allowing increasing humidity in the air, which then was transported to the mountainous areas and orographically lifted, resulting in extremely heavy precipitation at night.

    Geophys. Res. Lett. 10.1002/2015GL064479 (2015).

  6. Plant Science

    Unlocking artemisinin's biosynthetic secrets

    1. Pamela J. Hines

    The malaria drug artemisinin is isolated from Artemisia annua plants

    PHOTO: © MANFRED RUCKSZIO/ALAMY

    The emergence of drug-resistant parasites presents a major barrier to controlling human malaria. Artemisinin is the recommended first-line treatment for uncomplicated mal aria, but demand outstrips drugmakers' ability to cultivate the source, the Chinese herb Artemisia annua. A better understanding of the biosynthetic pathway could enhance scientists' ability to produce artemisinin from yeast, increasing the drug's availability. Bryant et al. explored the proteome of artemisinin-producing hairs stripped off the plant, cross-matching with genomic information to identify proteins. Key to the final steps of artemisinin biosynthesis may be enzymes like cyclophilins and peroxidases, hinting that steps that can proceed nonenzymatically may nonetheless get an enzymatic turbo-boost.

    BMC Plant Biol. 15, 175 (2015).

  7. Electron Transfer

    How to keep proteins protected from holes

    1. Jake Yeston

    Many enzymes are a little like circus performers juggling torches: They make highly reactive fragments that they then steer toward the intended targets, without getting burned themselves along the way. Gray and Winkler now present a hypothesis to account for some measure of enzymes' capacity for self-preservation from oxidative damage. They systematically surveyed structures in the Protein Data Bank to search for chains of three or more tyrosine and tryptophan residues in contexts where oxidation chemistry might be at play. The prevalence of these motifs suggests that the aromatic amino acids might shuttle positive holes (ensuing from oxidative electron transfer) from a fragile region of the protein to a safer site.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1512704112 (2015).

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