Editors' Choice

Science  09 Oct 2015:
Vol. 350, Issue 6257, pp. 174
  1. Drug Discovery

    A natural product map

    1. Valda Vinson

    Active compounds in marine sediment bacteria revealed through rapid screen

    PHOTO: ©LOGAN MOCK-BUNTING/CORBIS

    Natural products are a rich source for drug development, but the complexity of extracts from natural products makes it difficult to identify specific biologically active components. Kurita et al. describe a platform that predicts the identities and biological activities of compounds in a natural marine sediment extract. Methods exist to characterize the activities of extracts by profiling their effects in cell-based assays, and mass spectroscopy approaches can complex extracts and distinguish significant components from noise. Kurita et al. combine these methods in a platform termed Compound Activity Mapping in which they interrogate a library of 234 extracts and identify 11 known compound families and four new compounds that cause endoplasmic reticulum stress.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1507743112 (2015).

  2. Neuroscience

    Processing smells to elicit emotions

    1. Peter Stern

    The amygdala is a brain region that plays an important role in emotions. Emotional processes in rodents depend heavily on olfaction. Mice transmit olfactory cues through two separate pathways, the main and the accessory olfactory systems. These pathways detect odors and nonvolatile chemosignals, respectively. Keshavarzi et al. studied the responses of principal neurons in the medial amygdala. These neurons received convergent inputs from both olfactory pathways. However, their synapses were located on different parts of the dendritic tree. Compared to main olfactory system inputs, accessory olfactory inputs projected more onto the distal dendritic arbor and showed a broader summation and a higher output gain. Neurons in the medial amygdala thus process main and accessory olfactory information differently.

    J. Neurosci. 35, 13020 (2015).

  3. Human Genetics

    Crowding is bad for your health

    1. Laura M. Zahn

    Pathological protein aggregates are known to be associated with many human neurodegenerative diseases, such as Alzheimer's. The tendency to form aggregates can come from mutations that cause either a gain or loss of function in a protein. However, the number of proteins that contribute to disease-associated aggregates has not been explored. De Baets et al. computationally explored databases of human genetic variation, including those from cancer studies, to determine the likelihood of protein aggregations. They found that disease-associated genes showed a higher number of mutations predicted to increase the likelihood of aggregation. These findings indicate that aggregation may more commonly contribute to disease than previously thought.

    PLOS Comput. Biol. 10.1371/journal.pcbi.1004374 (2015).

  4. Inorganic Chemistry

    A magnesium catalyst to form B-N bonds

    1. Jake Yeston

    Boron and nitrogen pair up often in chemistry. Notable examples of that pairing include the classic ammonia borane adduct H3N-BH3; the hexagonal borazine, with alternating BH and NH groups; and the simple boron nitride BN, rivalling graphene in its exotic emerging two-dimensional properties. It may come as a surprise that not all B-N bonds are straightforward to make. Liptrot et al. report a magnesium catalyst that forms an underrepresented class of compounds linking amines to boron centers bearing two carbon or two oxygen bonds (R2N-BR'2) via release of H2. Specifically, the reaction is demonstrated for pinacolborane and 9-borabicyclononane with a variety of primary and secondary amines. Kinetics studies reveal intriguingly distinct mechanisms for each boron substrate.

    Angew. Chem. Int. Ed. 10.1002/anie.201505949 (2015).

  5. Education

    First-hand accounts of diversity

    1. Melissa McCartney

    Despite efforts to increase the number of minorities in science, underrepresentation persists. To investigate why, Gibau documented the experiences of minority graduate students participating in intervention programs. Data collected during individual interviews were analyzed to assess program effectiveness. These data exposed several challenges experienced by students, including withstanding the transition from historically black colleges and universities to predominantly white institutions, and the desire for authentic role models. Successes also were uncovered, specifically regarding the peer interaction associated with some programs. Although these data are not generalizable, it is necessary to have a student evaluation of programs designed to benefit them. With further collection of similar data, program administrators can begin to measure progress toward increasing diversity in science.

    CBE Life Sci. Edu. 10.1187/cbe.14-06-0103 (2015).

  6. Aging

    Aging gracefully, one organ at a time

    1. Stella M. Hurtley

    Protein abundance and cellular location change as rats age

    PHOTO: ALAN & SANDY CAREY/SCIENCE SOURCE

    You're as old as you feel, goes the old adage, but what is aging at the cellular level? On et al. performed a proteomic and transcriptomic analysis of the brains and livers of 6-month-old young rats and 2-year-old rats. More than 400 proteins changed in abundance between young and old animals, and more than 100 other proteins changed their cellular location, phosphorylation state, or splice form. Although some proteins and protein complexes were altered with age at similar rates, most changes were specific to one organ. These differences could be because of the very different life histories and functions of the two organs: Liver cells continually turn over and regenerate, whereas the brain mostly contains terminally differentiated postmitotic cells.

    Cell Syst. 10.1016/j.cels.2015.08.012 (2015).

  7. Applied Physics

    A not-so-rigid way to get past the jam

    1. Marc S. Lavine

    When highly concentrated particles become jammed, motion only happens in groups or through a cascading process. This rigidity transition, which for hard particles is accompanied by a transition to a solid-like state, is controlled by packing density. In some biological tissues, the packing fraction is almost always close to unity, but these materials still show glassy dynamics characteristic of the jammed state. Using the vertex model, Bi et al. show that the shape of the cell and the cell-to-cell adhesion correlate with whether the system is in a fluid or glassy state. They also identify a universal perimeter-to-area ratio where the jamming transition occurs.

    Nat. Phys. 10.1038/nphys3471 (2015).

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