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Preview: Proceedings of the National Academy of Sciences current issue

Proceedings of the National Academy of Sciences current issue



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In This Issue [This Week in PNAS]

2017-12-12T11:51:45-08:00

Crocodile bites, ancient butchery, and human evolution Linear marks and pits on a 2.5-million-year-old ungulate leg bone from Bouri, Ethiopia. Traces and pits found on the surfaces of fossilized bones have been used to infer the use of stone tools by hominids for butchering carcasses. But whether the marks represent...



Models with unequal transition rates favor marine origins of Cyanobacteria and photosynthetic eukaryotes [Biological Sciences]

2017-12-12T11:51:45-08:00

Using a broadly sampled, time-calibrated phylogeny of Cyanobacteria and photosynthetic eukaryotes, Sánchez-Baracaldo et al. (1) report that the most-recent common ancestor (MRCA) of Archaeplastida likely inhabited a low-salinity (freshwater) habitat, providing an advance on a longstanding debate about the ecological context for the origin of plastids (2). The freshwater ancestry...



Reply to Nakov et al.: Model choice requires biological insight when studying the ancestral habitat of photosynthetic eukaryotes [Biological Sciences]

2017-12-12T11:51:45-08:00

After reanalyzing the dataset presented by Sánchez-Baracaldo et al. (1), and contrary to their findings, Nakov et al. (2) conclude that the most-recent common ancestor of the Archaeplastida inhabited marine habitats. Nakov et al. (2) implemented additional parameters for independent transition rates among character states (i.e., freshwater, marine, brackish), claiming...



Traditional fisheries management is the best way to manage weak stocks [Biological Sciences]

2017-12-12T11:51:45-08:00

Hastings et al. (1) model a fishery with a weak and a strong stock. Using several examples from the US West Coast they conclude that marine protected areas (MPAs) are an effective way to allow harvest of strong stock while allowing for persistence of weak stocks and that MPAs have...



Reply to Hilborn: Role of marine reserves depends on assumptions [Biological Sciences]

2017-12-12T11:51:45-08:00

We appreciate the points made by Hilborn (1) that changing the assumptions we made could lead to different conclusions. In fact, our overall goal in developing the model in ref. 2 was similar to the goal in developing the model in ref. 3 to indicate how a model with clear...



Albatrosses hooked in the wind of change [Sustainability Science]

2017-12-12T11:51:45-08:00

Marine megafauna, a key component of ocean condition and functioning (1), is increasingly threatened by direct exploitation, incidental capture of nontarget species or bycatch, competition for forage fish by fisheries, pollution, and rapid ongoing climate change (2, 3). Seabirds are particularly at risk and their conservation status has deteriorated faster...



Revised taphonomic perspective on African Plio-Pleistocene fauna [Anthropology]

2017-12-12T11:51:45-08:00

A recent article in PNAS by Sahle et al. (1) entitled “Hominid butchers and biting crocodiles in the African Plio–Pleistocene” is an important contribution to our theoretical and methodological approaches to human origins research. It emphasizes the problem of equifinality in prehistoric studies (different agencies producing the same or similar...



Vertebrate body size jumps the Wright way [Evolution]

2017-12-12T11:51:45-08:00

Fossil data provide copious evidence that anatomical (morphological) change within individual lineages is not constant: short bursts of great change commonly separate long durations of little change (1, 2). Despite this, most models of morphological change assume that probabilities of morphological character change are the same from one generation to...



Patterns of coevolving amino acids unveil structural and dynamical domains [Biophysics and Computational Biology]

2017-12-12T11:51:45-08:00

Patterns of interacting amino acids are so preserved within protein families that the sole analysis of evolutionary comutations can identify pairs of contacting residues. It is also known that evolution conserves functional dynamics, i.e., the concerted motion or displacement of large protein regions or domains. Is it, therefore, possible to...



Direct measurements of meltwater runoff on the Greenland ice sheet surface [Earth, Atmospheric, and Planetary Sciences]

2017-12-12T11:51:45-08:00

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and...



Coupled European and Greenland last glacial dust activity driven by North Atlantic climate [Earth, Atmospheric, and Planetary Sciences]

2017-12-12T11:51:46-08:00

Centennial-scale mineral dust peaks in last glacial Greenland ice cores match the timing of lowest Greenland temperatures, yet little is known of equivalent changes in dust-emitting regions, limiting our understanding of dust−climate interaction. Here, we present the most detailed and precise age model for European loess dust deposits to date,...



Storm, rogue wave, or tsunami origin for megaclast deposits in western Ireland and North Island, New Zealand? [Earth, Atmospheric, and Planetary Sciences]

2017-12-12T11:51:46-08:00

The origins of boulderite deposits are investigated with reference to the present-day foreshore of Annagh Head, NW Ireland, and the Lower Miocene Matheson Formation, New Zealand, to resolve disputes on their origin and to contrast and compare the deposits of tsunamis and storms. Field data indicate that the Matheson Formation,...



Ideals, practices, and future prospects of stakeholder involvement in sustainability science [Sustainability Science]

2017-12-12T11:51:46-08:00

This paper evaluates current stakeholder involvement (SI) practices in science through a web-based survey among scholars and researchers engaged in sustainability or transition research. It substantiates previous conceptual work with evidence from practice by building on four ideal types of SI in science. The results give an interesting overview of...



Prenatal stress accelerates offspring growth to compensate for reduced maternal investment across mammals [Anthropology]

2017-12-12T11:51:46-08:00

Across mammals, prenatal maternal stress (PREMS) affects many aspects of offspring development, including offspring growth. However, how PREMS translates to offspring growth is inconsistent, even within species. To explain the full range of reported effects of prenatal adversity on offspring growth, we propose an integrative hypothesis: developmental constraints and a...



Phosphorylation of CENP-C by Aurora B facilitates kinetochore attachment error correction in mitosis [Biochemistry]

2017-12-12T11:51:46-08:00

Kinetochores are superprotein complexes that orchestrate chromosome segregation via a dynamic interaction with spindle microtubules. A physical connection between CENP-C and the Mis12–Ndc80–Knl1 (KMN) protein network is an important pathway that is used to assemble kinetochores on CENP-A nucleosomes. Multiple outer kinetochore components are phosphorylated by Aurora B kinase to...



Interaction of intramembrane metalloprotease SpoIVFB with substrate Pro-{sigma}K [Biochemistry]

2017-12-12T11:51:46-08:00

Intramembrane proteases (IPs) cleave membrane-associated substrates in nearly all organisms and regulate diverse processes. A better understanding of how these enzymes interact with their substrates is necessary for rational design of IP modulators. We show that interaction of Bacillus subtilis IP SpoIVFB with its substrate Pro-σK depends on particular residues...



EB1-binding-myomegalin protein complex promotes centrosomal microtubules functions [Cell Biology]

2017-12-12T11:51:46-08:00

Control of microtubule dynamics underlies several fundamental processes such as cell polarity, cell division, and cell motility. To gain insights into the mechanisms that control microtubule dynamics during cell motility, we investigated the interactome of the microtubule plus-end–binding protein end-binding 1 (EB1). Via molecular mapping and cross-linking mass spectrometry we...



AP-4 mediates export of ATG9A from the trans-Golgi network to promote autophagosome formation [Cell Biology]

2017-12-12T11:51:46-08:00

AP-4 is a member of the heterotetrameric adaptor protein (AP) complex family involved in protein sorting in the endomembrane system of eukaryotic cells. Interest in AP-4 has recently risen with the discovery that mutations in any of its four subunits cause a form of hereditary spastic paraplegia (HSP) with intellectual...



Bicaudal D2 facilitates the cytoplasmic trafficking and nuclear import of HIV-1 genomes during infection [Cell Biology]

2017-12-12T11:51:46-08:00

Numerous viruses, including HIV-1, exploit the microtubule network to traffic toward the nucleus during infection. Although numerous studies have observed a role for the minus-end microtubule motor dynein in HIV-1 infection, the mechanism by which the viral core containing the viral genome associates with dynein and induces its perinuclear trafficking...



Smek1/2 is a nuclear chaperone and cofactor for cleaved Wnt receptor Ryk, regulating cortical neurogenesis [Developmental Biology]

2017-12-12T11:51:46-08:00

The receptor-like tyrosine kinase (Ryk), a Wnt receptor, is important for cell fate determination during corticogenesis. During neuronal differentiation, the Ryk intracellular domain (ICD) is cleaved. Cleavage of Ryk and nuclear translocation of Ryk-ICD are required for neuronal differentiation. However, the mechanism of translocation and how it regulates neuronal differentiation...



FMRFamide-like peptides expand the behavioral repertoire of a densely connected nervous system [Developmental Biology]

2017-12-12T11:51:46-08:00

Animals, including humans, can adapt to environmental stress through phenotypic plasticity. The free-living nematode Caenorhabditis elegans can adapt to harsh environments by undergoing a whole-animal change, involving exiting reproductive development and entering the stress-resistant dauer larval stage. The dauer is a dispersal stage with dauer-specific behaviors for finding and stowing...



High-resolution mapping of cis-regulatory variation in budding yeast [Genetics]

2017-12-12T11:51:46-08:00

Genetic variants affecting gene-expression levels are a major source of phenotypic variation. The approximate locations of these variants can be mapped as expression quantitative trait loci (eQTLs); however, a major limitation of eQTLs is their low resolution, which precludes investigation of the causal variants and their molecular mechanisms. Here we...



Precision genome editing using synthesis-dependent repair of Cas9-induced DNA breaks [Genetics]

2017-12-12T11:51:46-08:00

The RNA-guided DNA endonuclease Cas9 has emerged as a powerful tool for genome engineering. Cas9 creates targeted double-stranded breaks (DSBs) in the genome. Knockin of specific mutations (precision genome editing) requires homology-directed repair (HDR) of the DSB by synthetic donor DNAs containing the desired edits, but HDR has been reported...



Improved detection of synthetic lethal interactions in Drosophila cells using variable dose analysis (VDA) [Genetics]

2017-12-12T11:51:46-08:00

Synthetic sick or synthetic lethal (SS/L) screens are a powerful way to identify candidate drug targets to specifically kill tumor cells, but this approach generally suffers from low consistency between screens. We found that many SS/L interactions involve essential genes and are therefore detectable within a limited range of knockdown...



Transient receptor potential channel 6 regulates abnormal cardiac S-nitrosylation in Duchenne muscular dystrophy [Medical Sciences]

2017-12-12T11:51:46-08:00

Duchenne muscular dystrophy (DMD) is an X-linked disorder with dystrophin loss that results in skeletal and cardiac muscle weakening and early death. Loss of the dystrophin–sarcoglycan complex delocalizes nitric oxide synthase (NOS) to alter its signaling, and augments mechanosensitive intracellular Ca2+ influx. The latter has been coupled to hyperactivation of...



WhiB6 regulation of ESX-1 gene expression is controlled by a negative feedback loop in Mycobacterium marinum [Microbiology]

2017-12-12T11:51:46-08:00

ESX (ESAT-6 system) export systems play diverse roles across mycobacterial species. Interestingly, genetic disruption of ESX systems in different species does not result in an accumulation of protein substrates in the mycobacterial cell. However, the mechanisms underlying this observation are elusive. We hypothesized that the levels of ESX substrates were...



Characterization of SPP inhibitors suppressing propagation of HCV and protozoa [Microbiology]

2017-12-12T11:51:46-08:00

Signal peptide peptidase (SPP) is an intramembrane aspartic protease involved in the maturation of the core protein of hepatitis C virus (HCV). The processing of HCV core protein by SPP has been reported to be critical for the propagation and pathogenesis of HCV. Here we examined the inhibitory activity of...



Osmosensing by the bacterial PhoQ/PhoP two-component system [Microbiology]

2017-12-12T11:51:46-08:00

The PhoQ/PhoP two-component system plays an essential role in the response of enterobacteria to the environment of their mammalian hosts. It is known to sense several stimuli that are potentially associated with the host, including extracellular magnesium limitation, low pH, and the presence of cationic antimicrobial peptides. Here, we show...



Expansion microscopy of zebrafish for neuroscience and developmental biology studies [Neuroscience]

2017-12-12T11:51:46-08:00

Expansion microscopy (ExM) allows scalable imaging of preserved 3D biological specimens with nanoscale resolution on fast diffraction-limited microscopes. Here, we explore the utility of ExM in the larval and embryonic zebrafish, an important model organism for the study of neuroscience and development. Regarding neuroscience, we found that ExM enabled the...



Phosphorylation of huntingtin at residue T3 is decreased in Huntington’s disease and modulates mutant huntingtin protein conformation [Neuroscience]

2017-12-12T11:51:46-08:00

Posttranslational modifications can have profound effects on the biological and biophysical properties of proteins associated with misfolding and aggregation. However, their detection and quantification in clinical samples and an understanding of the mechanisms underlying the pathological properties of misfolding- and aggregation-prone proteins remain a challenge for diagnostics and therapeutics development....



Vasopressin excites interneurons to suppress hippocampal network activity across a broad span of brain maturity at birth [Neuroscience]

2017-12-12T11:51:46-08:00

During birth in mammals, a pronounced surge of fetal peripheral stress hormones takes place to promote survival in the transition to the extrauterine environment. However, it is not known whether the hormonal signaling involves central pathways with direct protective effects on the perinatal brain. Here, we show that arginine vasopressin...



Additive effects of climate and fisheries drive ongoing declines in multiple albatross species [Sustainability Science]

2017-12-12T11:51:46-08:00

Environmental and anthropogenic factors often drive population declines in top predators, but how their influences may combine remains unclear. Albatrosses are particularly threatened. They breed in fast-changing environments, and their extensive foraging ranges expose them to incidental mortality (bycatch) in multiple fisheries. The albatross community at South Georgia includes globally...



Proteomics of phosphorylation and protein dynamics during fertilization and meiotic exit in the Xenopus egg [Systems Biology]

2017-12-12T11:51:46-08:00

Fertilization releases the meiotic arrest and initiates the events that prepare the egg for the ensuing developmental program. Protein degradation and phosphorylation are known to regulate protein activity during this process. However, the full extent of protein loss and phosphoregulation is still unknown. We examined absolute protein and phosphosite dynamics...



Hominid butchers and biting crocodiles in the African Plio-Pleistocene [Anthropology]

2017-12-12T11:51:45-08:00

Zooarchaeologists have long relied on linear traces and pits found on the surfaces of ancient bones to infer ancient hominid behaviors such as slicing, chopping, and percussive actions during butchery of mammal carcasses. However, such claims about Plio–Pleistocene hominids rely mostly on very small assemblages of bony remains. Furthermore, recent...



Inner Workings: Spacecraft dare to fly close to the sun [Astronomy]

2017-12-12T11:51:45-08:00

A wide swath of North America was reminded during last summer’s eclipse that you can’t stare at the sun without protection. But to study the sun, space probes have to do much more than stare. They have to get extremely close to the sun’s unforgiving environs. Next year, two solar...



Structures and enzymatic mechanisms of phycobiliprotein lyases CpcE/F and PecE/F [Biochemistry]

2017-12-12T11:51:45-08:00

The light-harvesting phycobilisome in cyanobacteria and red algae requires the lyase-catalyzed chromophorylation of phycobiliproteins. There are three functionally distinct lyase families known. The heterodimeric E/F type is specific for attaching bilins covalently to α-subunits of phycocyanins and phycoerythrins. Unlike other lyases, the lyase also has chromophore-detaching activity. A subclass of...



SUMOylation and ubiquitination reciprocally regulate {alpha}-synuclein degradation and pathological aggregation [Biochemistry]

2017-12-12T11:51:45-08:00

α-Synuclein accumulation is a pathological hallmark of Parkinson’s disease (PD). Ubiquitinated α-synuclein is targeted to proteasomal or lysosomal degradation. Here, we identify SUMOylation as a major mechanism that counteracts ubiquitination by different E3 ubiquitin ligases and regulates α-synuclein degradation. We report that PIAS2 promotes SUMOylation of α-synuclein, leading to a...



Kinematics of flagellar swimming in Euglena gracilis: Helical trajectories and flagellar shapes [Biophysics and Computational Biology]

2017-12-12T11:51:45-08:00

The flagellar swimming of euglenids, which are propelled by a single anterior flagellum, is characterized by a generalized helical motion. The 3D nature of this swimming motion, which lacks some of the symmetries enjoyed by more common model systems, and the complex flagellar beating shapes that power it make its...



Proton movement and coupling in the POT family of peptide transporters [Biophysics and Computational Biology]

2017-12-12T11:51:45-08:00

POT transporters represent an evolutionarily well-conserved family of proton-coupled transport systems in biology. An unusual feature of the family is their ability to couple the transport of chemically diverse ligands to an inwardly directed proton electrochemical gradient. For example, in mammals, fungi, and bacteria they are predominantly peptide transporters, whereas...



Optimal nutrient exchange and immune responses operate in partner specificity in the cnidarian-dinoflagellate symbiosis [Cell Biology]

2017-12-12T11:51:45-08:00

The relationship between corals and dinoflagellates of the genus Symbiodinium is fundamental to the functioning of coral ecosystems. It has been suggested that reef corals may adapt to climate change by changing their dominant symbiont type to a more thermally tolerant one, although the capacity for such a shift is...



Amorphous MoS3 as the sulfur-equivalent cathode material for room-temperature Li-S and Na-S batteries [Chemistry]

2017-12-12T11:51:45-08:00

Many problems associated with Li–S and Na–S batteries essentially root in the generation of their soluble polysulfide intermediates. While conventional wisdom mainly focuses on trapping polysulfides at the cathode using various functional materials, few strategies are available at present to fully resolve or circumvent this long-standing issue. In this study,...



Chiral intertwined spirals and magnetic transition dipole moments dictated by cylinder helicity [Chemistry]

2017-12-12T11:51:45-08:00

The presence of anomalous chirality in a roll of graphitic carbon sheets has been recognized since the discovery of carbon nanotubes, which are becoming available in higher quantities through the isolation of chiral single-wall congeners with high purity. Exploration of the properties arising from cylinder chirality is expected to expand...



Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds [Chemistry]

2017-12-12T11:51:45-08:00

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more...



Eph-ephrin signaling modulated by polymerization and condensation of receptors [Chemistry]

2017-12-12T11:51:45-08:00

Eph receptor signaling plays key roles in vertebrate tissue boundary formation, axonal pathfinding, and stem cell regeneration by steering cells to positions defined by its ligand ephrin. Some of the key events in Eph-ephrin signaling are understood: ephrin binding triggers the clustering of the Eph receptor, fostering transphosphorylation and signal...



Using deep learning and Google Street View to estimate the demographic makeup of neighborhoods across the United States [Computer Sciences]

2017-12-12T11:51:45-08:00

The United States spends more than $250 million each year on the American Community Survey (ACS), a labor-intensive door-to-door study that measures statistics relating to race, gender, education, occupation, unemployment, and other demographic factors. Although a comprehensive source of data, the lag between demographic changes and their appearance in the...



Trunk neural crest origin of dermal denticles in a cartilaginous fish [Developmental Biology]

2017-12-12T11:51:45-08:00

Cartilaginous fishes (e.g., sharks and skates) possess a postcranial dermal skeleton consisting of tooth-like “denticles” embedded within their skin. As with teeth, the principal skeletal tissue of dermal denticles is dentine. In the head, cranial neural crest cells give rise to the dentine-producing cells (odontoblasts) of teeth. However, trunk neural...



Membrane targeting of inhibitory Smads through palmitoylation controls TGF-{beta}/BMP signaling [Developmental Biology]

2017-12-12T11:51:45-08:00

TGF-β/BMP (bone morphogenetic protein) signaling pathways play conserved roles in controlling embryonic development, tissue homeostasis, and stem cell regulation. Inhibitory Smads (I-Smads) have been shown to negatively regulate TGF-β/BMP signaling by primarily targeting the type I receptors for ubiquitination and turnover. However, little is known about how I-Smads access the...



Causes of ice age intensification across the Mid-Pleistocene Transition [Earth, Atmospheric, and Planetary Sciences]

2017-12-12T11:51:45-08:00

During the Mid-Pleistocene Transition (MPT; 1,200–800 kya), Earth’s orbitally paced ice age cycles intensified, lengthened from ∼40,000 (∼40 ky) to ∼100 ky, and became distinctly asymmetrical. Testing hypotheses that implicate changing atmospheric CO2 levels as a driver of the MPT has proven difficult with available observations. Here, we use orbitally...



Bulk magnetic domain stability controls paleointensity fidelity [Earth, Atmospheric, and Planetary Sciences]

2017-12-12T11:51:45-08:00

Nonideal, nonsingle-domain magnetic grains are ubiquitous in rocks; however, they can have a detrimental impact on the fidelity of paleomagnetic records—in particular the determination of ancient magnetic field strength (paleointensity), a key means of understanding the evolution of the earliest geodynamo and the formation of the solar system. As a...



Relationship of tropospheric stability to climate sensitivity and Earth’s observed radiation budget [Earth, Atmospheric, and Planetary Sciences]

2017-12-12T11:51:45-08:00

Climate feedbacks generally become smaller in magnitude over time under CO2 forcing in coupled climate models, leading to an increase in the effective climate sensitivity, the estimated global-mean surface warming in steady state for doubled CO2. Here, we show that the evolution of climate feedbacks in models is consistent with...



Inequality in nature and society [Ecology]

2017-12-12T11:51:45-08:00

Most societies are economically dominated by a small elite, and similarly, natural communities are typically dominated by a small fraction of the species. Here we reveal a strong similarity between patterns of inequality in nature and society, hinting at fundamental unifying mechanisms. We show that chance alone will drive 1%...



Predicting phenological shifts in a changing climate [Ecology]

2017-12-12T11:51:45-08:00

Phenological shifts constitute one of the clearest manifestations of climate warming. Advanced emergence is widely reported in high-latitude ectotherms, but a significant number of species exhibit delayed, or no change in, emergence. Here we present a mechanistic theoretical framework that reconciles these disparate observations and predicts population-level phenological patterns based...



In situ modeling of multimodal floral cues attracting wild pollinators across environments [Ecology]

2017-12-12T11:51:45-08:00

With more than 80% of flowering plant species specialized for animal pollination, understanding how wild pollinators utilize resources across environments can encourage efficient planting and maintenance strategies to maximize pollination and establish resilience in the face of environmental change. A fundamental question is how generalist pollinators recognize “flower objects” in...



Fluid-driven origami-inspired artificial muscles [Engineering]

2017-12-12T11:51:45-08:00

Artificial muscles hold promise for safe and powerful actuation for myriad common machines and robots. However, the design, fabrication, and implementation of artificial muscles are often limited by their material costs, operating principle, scalability, and single-degree-of-freedom contractile actuation motions. Here we propose an architecture for fluid-driven origami-inspired artificial muscles. This...



Long-term dopamine neurochemical monitoring in primates [Engineering]

2017-12-12T11:51:45-08:00

Many debilitating neuropsychiatric and neurodegenerative disorders are characterized by dopamine neurotransmitter dysregulation. Monitoring subsecond dopamine release accurately and for extended, clinically relevant timescales is a critical unmet need. Especially valuable has been the development of electrochemical fast-scan cyclic voltammetry implementing microsized carbon fiber probe implants to record fast millisecond changes...



Pulsed evolution shaped modern vertebrate body sizes [Evolution]

2017-12-12T11:51:45-08:00

The relative importance of different modes of evolution in shaping phenotypic diversity remains a hotly debated question. Fossil data suggest that stasis may be a common mode of evolution, while modern data suggest some lineages experience very fast rates of evolution. One way to reconcile these observations is to imagine...



Def1 interacts with TFIIH and modulates RNA polymerase II transcription [Genetics]

2017-12-12T11:51:45-08:00

The DNA damage response is an essential process for the survival of living cells. In a subset of stress-responsive genes in humans, Elongin controls transcription in response to multiple stimuli, such as DNA damage, oxidative stress, and heat shock. Yeast Elongin (Ela1-Elc1), along with Def1, is known to facilitate ubiquitylation...



A STAT3-dependent transcriptional circuitry inhibits cytotoxic gene expression in T cells [Immunology and Inflammation]

2017-12-12T11:51:45-08:00

CD8+ T cells are preprogrammed for cytotoxic differentiation in the thymus as they acquire expression of the transcription factor Runx3. However, a subset of effector CD8+ T cells (Tc17) produce IL-17 and fail to express cytotoxic genes. Here, we show that the transcription factors directing IL-17 production, STAT3 and RORγt,...



Broad detection of bacterial type III secretion system and flagellin proteins by the human NAIP/NLRC4 inflammasome [Immunology and Inflammation]

2017-12-12T11:51:45-08:00

Inflammasomes are cytosolic multiprotein complexes that initiate host defense against bacterial pathogens by activating caspase-1–dependent cytokine secretion and cell death. In mice, specific nucleotide-binding domain, leucine-rich repeat-containing family, apoptosis inhibitory proteins (NAIPs) activate the nucleotide-binding domain, leucine-rich repeat-containing family, CARD domain-containing protein 4 (NLRC4) inflammasome upon sensing components of the...



Core Concept: Cryopreservation aims to engineer novel ways to freeze, store, and thaw organs [Medical Sciences]

2017-12-12T11:51:45-08:00

Five years ago, even top cryobiologists doubted that a human organ would ever be successfully frozen and thawed. It felt like “a long, long scientific step” from the freezing of cells or millimeter-thick tissues to the freezing of whole organs, says Janet Elliott, Canada Research Chair in Thermodynamics at the...



DNAJB1-PRKACA fusion kinase interacts with {beta}-catenin and the liver regenerative response to drive fibrolamellar hepatocellular carcinoma [Medical Sciences]

2017-12-12T11:51:45-08:00

A segmental deletion resulting in DNAJB1–PRKACA gene fusion is now recognized as the signature genetic event of fibrolamellar hepatocellular carcinoma (FL-HCC), a rare but lethal liver cancer that primarily affects adolescents and young adults. Here we implement CRISPR-Cas9 genome editing and transposon-mediated somatic gene transfer to demonstrate that expression of...



Protective effects of agonists of growth hormone-releasing hormone (GHRH) in early experimental diabetic retinopathy [Medical Sciences]

2017-12-12T11:51:45-08:00

The potential therapeutic effects of agonistic analogs of growth hormone-releasing hormone (GHRH) and their mechanism of action were investigated in diabetic retinopathy (DR). Streptozotocin-induced diabetic rats (STZ-rats) were treated with 15 μg/kg GHRH agonist, MR-409, or GHRH antagonist, MIA-602. At the end of treatment, morphological and biochemical analyses assessed the...



{Delta}Np63-mediated regulation of hyaluronic acid metabolism and signaling supports HNSCC tumorigenesis [Medical Sciences]

2017-12-12T11:51:45-08:00

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, and several molecular pathways that underlie the molecular tumorigenesis of HNSCC have been identified. Among them, amplification or overexpression of ΔNp63 isoforms is observed in the majority of HNSCCs. Here, we unveiled a ΔNp63-dependent transcriptional program...



Synaptic homeostasis requires the membrane-proximal carboxy tail of GluA2 [Neuroscience]

2017-12-12T11:51:45-08:00

Bidirectional scaling of synaptic transmission, expressed as a compensatory change in quantal size following chronic activity perturbation, is a critical effector mechanism underlying homeostatic plasticity in the brain. An emerging model posits that the GluA2 AMPA receptor (AMPAR) subunit may be important for the bidirectional scaling of excitatory transmission; however,...



Loss of APOBEC1 RNA-editing function in microglia exacerbates age-related CNS pathophysiology [Neuroscience]

2017-12-12T11:51:45-08:00

Microglia (MG), a heterogeneous population of phagocytic cells, play important roles in central nervous system (CNS) homeostasis and neural plasticity. Under steady-state conditions, MG maintain homeostasis by producing antiinflammatory cytokines and neurotrophic factors, support myelin production, and remove synapses and cellular debris, as well as participating in “cross-correction,” a process...



On the role of the corpus callosum in interhemispheric functional connectivity in humans [Neuroscience]

2017-12-12T11:51:45-08:00

Resting state functional connectivity is defined in terms of temporal correlations between physiologic signals, most commonly studied using functional magnetic resonance imaging. Major features of functional connectivity correspond to structural (axonal) connectivity. However, this relation is not one-to-one. Interhemispheric functional connectivity in relation to the corpus callosum presents a case...



Robust zero resistance in a superconducting high-entropy alloy at pressures up to 190 GPa [Physics]

2017-12-12T11:51:45-08:00

We report the observation of extraordinarily robust zero-resistance superconductivity in the pressurized (TaNb)0.67(HfZrTi)0.33 high-entropy alloy––a material with a body-centered-cubic crystal structure made from five randomly distributed transition-metal elements. The transition to superconductivity (TC) increases from an initial temperature of 7.7 K at ambient pressure to 10 K at ∼60 GPa,...



Spin susceptibility of charge-ordered YBa2Cu3Oy across the upper critical field [Physics]

2017-12-12T11:51:45-08:00

The value of the upper critical field Hc2, a fundamental characteristic of the superconducting state, has been subject to strong controversy in high-Tc copper oxides. Since the issue has been tackled almost exclusively by macroscopic techniques so far, there is a clear need for local-probe measurements. Here, we use 17O...



Glycosyltransferase MDR1 assembles a dividing ring for mitochondrial proliferation comprising polyglucan nanofilaments [Plant Biology]

2017-12-12T11:51:45-08:00

Mitochondria, which evolved from a free-living bacterial ancestor, contain their own genomes and genetic systems and are produced from preexisting mitochondria by binary division. The mitochondrion-dividing (MD) ring is the main skeletal structure of the mitochondrial division machinery. However, the assembly mechanism and molecular identity of the MD ring are...



Speaker gaze increases information coupling between infant and adult brains [Psychological and Cognitive Sciences]

2017-12-12T11:51:45-08:00

When infants and adults communicate, they exchange social signals of availability and communicative intention such as eye gaze. Previous research indicates that when communication is successful, close temporal dependencies arise between adult speakers’ and listeners’ neural activity. However, it is not known whether similar neural contingencies exist within adult–infant dyads....



Development of self-protective biases in response to social evaluative feedback [Psychological and Cognitive Sciences]

2017-12-12T11:51:45-08:00

Adolescence is a developmental period marked by heightened attunement to social evaluation. While adults have been shown to enact self-protective processes to buffer their self-views from evaluative threats like peer rejection, it is unclear whether adolescents avail themselves of the same defenses. The present study examines how social evaluation shapes...



Hydraulic fracturing near domestic groundwater wells [Sustainability Science]

2017-12-12T11:51:45-08:00

Hydraulic fracturing operations are generating considerable discussion about their potential to contaminate aquifers tapped by domestic groundwater wells. Groundwater wells located closer to hydraulically fractured wells are more likely to be exposed to contaminants derived from on-site spills and well-bore failures, should they occur. Nevertheless, the proximity of hydraulic fracturing...



Epitranscriptomic profiling across cell types reveals associations between APOBEC1-mediated RNA editing, gene expression outcomes, and cellular function [Systems Biology]

2017-12-12T11:51:45-08:00

Epitranscriptomics refers to posttranscriptional alterations on an mRNA sequence that are dynamic and reproducible, and affect gene expression in a similar way to epigenetic modifications. However, the functional relevance of those modifications for the transcript, the cell, and the organism remain poorly understood. Here, we focus on RNA editing and...



Correction for Schroeder et al., Mutagenic cost of ribonucleotides in bacterial DNA [Correction]

2017-12-12T11:51:46-08:00

GENETICS Correction for “Mutagenic cost of ribonucleotides in bacterial DNA,” by Jeremy W. Schroeder, Justin R. Randall, William G. Hirst, Michael E. O’Donnell, and Lyle A. Simmons, which was first published October 16, 2017; 10.1073/pnas.1710995114 (Proc Natl Acad Sci USA 114:11733–11738). The authors note that, due to a printer’s error,...



Correction for Alvarez et al., Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol [Correction]

2017-12-12T11:51:46-08:00

GENETICS Correction for “Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol,” by Monica I. Alvarez, Luke C. Glover, Peter Luo, Liuyang Wang, Elizabeth Theusch, Stefan H. Oehlers, Eric M. Walton, Trinh Thi Bich Tram, Yu-Lin Kuang, Jerome I. Rotter, Colleen M. McClean, Nguyen...



Correction for Schulte et al., Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn-soybean croplands [Correction]

2017-12-12T11:51:46-08:00

SUSTAINABILITY SCIENCE Correction for “Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn–soybean croplands,” by Lisa A. Schulte, Jarad Niemi, Matthew J. Helmers, Matt Liebman, J. Gordon Arbuckle, David E. James, Randall K. Kolka, Matthew E. O’Neal, Mark D. Tomer, John C. Tyndall, Heidi Asbjornsen, Pauline...



Correction to Supporting Information for Alvarez et al., Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol [SI Correction]

2017-12-12T11:51:46-08:00

GENETICS Correction to Supporting Information for “Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol,” by Monica I. Alvarez, Luke C. Glover, Peter Luo, Liuyang Wang, Elizabeth Theusch, Stefan H. Oehlers, Eric M. Walton, Trinh Thi Bich Tram, Yu-Lin Kuang, Jerome I. Rotter, Colleen...