| | Cell biology: Death drags down the neighbourhood
An analysis of dying cells reveals that they play an active part in modifying tissue shape by pulling on neighbouring cells. This induces neighbouring cells to contract at their apices, which results in tissue folding.
| Biochemistry: Breaking methane
The most powerful oxidant found in nature is compound Q, an enzymatic intermediate that oxidizes methane. New spectroscopic data have resolved the long-running controversy about Q's chemical structure.
| Biocontainment of genetically modified organisms by synthetic protein design
Essential enzymes in genetically modified organisms are computationally redesigned to functionally depend on non-standard amino acids, thereby achieving biocontainment with unprecedented resistance to escape by evolution or by supplementation with environmental metabolites.
| The paraventricular thalamus controls a central amygdala fear circuit
Inhibiting projections from the paraventricular nucleus of the thalamus to a specific division of the amygdala prevents fear conditioning in mice, indicating an important role for the thalamus–amygdala circuit in establishing and maintaining fear responses.
| Growth and host interaction of mouse segmented filamentous bacteria in vitro
Development of a segmented filamentous bacteria and host cell co-culturing system that supports filamentation, segmentation, and differentiation to release viable infectious intracellular offspring.
| A temporal shift in the circuits mediating retrieval of fear memory
Dissociating early from late fear memory retrieval in rats reveals that while the projection from the prelimbic prefrontal cortex to the amygdala is critical for fear memory retrieval at early time points, a separate circuit involving the paraventricular region of the dorsal midline thalamus is critical for fear memory retrieval at late time points, establishing the paraventricular region as a critical maintenance/retrieval node during the transition from short- to long-term fear memory.
| G-protein-independent coupling of MC4R to Kir7.1 in hypothalamic neurons
α-MSH and AgRP, two hypothalamus-derived peptides with opposing actions on the melanocortin-4 receptor (MC4R), modulate neurons driving feeding behaviour; although previous downstream mechanisms of cellular modulation by these peptides have been determined, here α-MSH and AgRP are shown to regulate neural activity by coupling MC4R to Kir7.1 potassium channels and closing or opening them, respectively.
| Distinct relationships of parietal and prefrontal cortices to evidence accumulation
A method to measure the precise relationship between neuronal firing rates and the representation of accumulated evidence is described; results in the parietal and prefrontal cortex of rats, together with transient optogenetic inactivation of the prefrontal cortex, challenge the prevailing view that the prefrontal cortex is part of the neural circuit for accumulating evidence, and suggest that neurons in parietal and prefrontal areas have distinct relationships to evidence accumulation in decision-making.
| Recoded organisms engineered to depend on synthetic amino acids
Construction of a series of genomically recoded organisms whose growth is restricted by the expression of essential genes dependent on exogenously supplied synthetic amino acids introduces novel orthogonal barriers between these engineered organisms and the environment, thereby creating safer genetically modified organisms.
| Common genetic variants influence human subcortical brain structures
Genome-wide association studies are used to identify common genetic variants that affect the structure of selected subcortical regions of the human brain; their identification provides insight into the causes of variability in brain development and may help to determine mechanisms of neuropsychiatric dysfunction.
| Emotional learning selectively and retroactively strengthens memories for related events
Initially weak episodic memories in humans can be selectively enhanced and consolidated following later emotional learning involving conceptually related information, suggesting a mechanism for how we can remember initially inconsequential information after a relevant later experience.
| Recharge of a subglacial lake by surface meltwater in northeast Greenland
Observations of rapid, persistent elevation gains that occur on the ice surface above a subglacial lake as the lake is refilled with surface meltwater during the summer melt period in Greenland show that surface meltwater may be trapped and stored at the bed of an ice sheet, affecting ice dynamics downstream.
| Apico-basal forces exerted by apoptotic cells drive epithelium folding
Apoptotic cell death is required for morphogenesis of the developing leg joint of fruitflies; using this model system, the authors show here that within apoptotic cells a transient pulling force exerted through a highly dynamic apico-basal myosin II cable-like structure acts as a mechanical signal to increase tissue tension and modify tissue shape.
| Structure of the key species in the enzymatic oxidation of methane to methanol
Time-resolved resonance Raman vibrational spectroscopy was used to study the mechanism of soluble methane monooxygenase and obtain structural information on the key reaction cycle intermediate, compound Q, which contains a unique dinuclear FeIV cluster that breaks the strong C-H bond of methane and inserts an oxygen atom (from O2) to form methanol.
| Genomic profiling of DNA methyltransferases reveals a role for DNMT3B in genic methylation
Genome-wide localization and activity analysis of the de novo DNA methyltransferases DNMT3A and DNMT3B in mouse embryonic stem cells identifies overlapping and individual targeting preferences to the genome, including a role for DNMT3B in gene body methylation.
| | Erratum: Deconstructing transcriptional heterogeneity in pluripotent stem cells | | Corrigendum: Mutant IDH inhibits HNF-4α to block hepatocyte differentiation and promote biliary cancer | | Corrigendum: Ultraviolet radiation accelerates BRAF-driven melanomagenesis by targeting TP53 | | | | | | FOCUS on: Immunology of the lung A series of Reviews and an animation specially commissioned by Nature Immunology explore the immunology of the lungs. Access is available free online for six months. | | | | | | | | | | | | | A new antibiotic kills pathogens without detectable resistance
From a new species of β-proteobacteria, an antibiotic called teixobactin that does not generate resistance has been characterized; the antibiotic has two different lipid targets in different bacterial cell wall synthesis components, which may explain why resistance was not observed.
Losee L. Ling, Tanja Schneider, Aaron J. Peoples et al. | Stable gold(III) catalysts by oxidative addition of a carbon–carbon bond
The facile synthesis of a stable Au(III) cationic complex is described; this gold catalyst exhibits hard, oxophilic Lewis acidity, enabling selective conjugate additions and a [2 + 2] cycloaddition reaction.
Chung-Yeh Wu, Takahiro Horibe, Christian Borch Jacobsen et al. | Endophilin marks and controls a clathrin-independent endocytic pathway
This study describes a fast, clathrin-independent endocytic pathway mediated by endophilin, dynamin and actin; the pathway is activated by ligand binding to a variety of cargo receptors, and endophilin-mediated endocytosis occurs primarily at the leading edges of cells where lamellipodin and the lipid PtdIns(3,4)P2 ensure endophilin targeting.
Emmanuel Boucrot, Antonio P. A. Ferreira, Leonardo Almeida-Souza et al. | Meikin is a conserved regulator of meiosis-I-specific kinetochore function
The long elusive mammalian meiosis-specific kinetochore factor has been identified in mice; MEIKIN—which plays an equivalent role to the yeast proteins Spo13 and Moa1—ensures mono-orientation, protects sister chromatid cohesion and recruits the kinase PLK1 to the kinetochores.
Jihye Kim, Kei-ichiro Ishiguro, Aya Nambu et al. | | Probabilistic reanalysis of twentieth-century sea-level rise
A statistical reassessment of the tide gauge record concludes that sea level rose at a rate of about 1.2 millimetres per year from 1901 to 1990, slightly lower than prior estimates and now consistent with estimates based on individual contributions to sea-level change; the estimates reported here from 1990 onwards are consistent with other work, suggesting that the recent acceleration in sea-level rise is greater than previously thought.
Carling C. Hay, Eric Morrow, Robert E. Kopp et al. | The mutational landscapes of genetic and chemical models of Kras-driven lung cancer
Whole-exome sequencing is used to compare the mutational landscape of adenomas from three mouse models of non-small-cell lung cancer, induced either by exposure to carcinogens or by genetic mutation of Kras; the results reveal that the two types of tumour have different mutational profiles and adopt different routes to tumour development.
Peter M. K. Westcott, Kyle D. Halliwill, Minh D. To et al. | Reductive dehalogenase structure suggests a mechanism for B12-dependent dehalogenation
X-ray crystallography and EPR spectroscopy are used to characterize a soluble, oxygen-tolerant reductive dehalogenase from Nitratireductor pacificus pht-3B; the data suggest that the cobalt in the cobalamin cofactor ligates the halogen atom of the substrate, directly abstracting the halogen atom via an oxidative addition.
Karl A. P. Payne, Carolina P. Quezada, Karl Fisher et al. | Structure and mechanism of the tRNA-dependent lantibiotic dehydratase NisB
Structural and biochemical studies show that the biosynthesis of the food preservative nisin involves the tRNA-dependent glutamylation of serine and threonine.
Manuel A. Ortega, Yue Hao, Qi Zhang et al. | Long-lived magnetism from solidification-driven convection on the pallasite parent body
Nanomagnetic imaging has been used to obtain a palaeomagnetic time series of two pallasite meteorites, revealing that their convection was driven by core solidification, which would have caused long-lived magnetic fields in the cores of early Solar System planetary bodies.
James F. J. Bryson, Claire I. O. Nichols, Julia Herrero-Albillos et al. | A basal ichthyosauriform with a short snout from the Lower Triassic of China
The Ichthyopterygia appeared in the fossil record as fully evolved, aquatic creatures, with nothing known about their transition from land to water, but now some light is shed on this transition by a fossil from the Lower Triassic of southern China of a small, primitive and possibly amphibious ichthyosaur-like creature, close to the common ancestry of ichthyosaurs and the obscure Hupehsuchia, a group of extinct aquatic reptiles known only from southern China.
Ryosuke Motani, Da-Yong Jiang, Guan-Bao Chen et al. | Endophilin-A2 functions in membrane scission in clathrin-independent endocytosis
Endophilin-A2 (endoA2) is shown to mediate clathrin-independent endocytosis of Shiga and cholera toxins, and to function in parallel with dynamin and actin in the pulling-force-driven scission of Shiga-toxin-induced tubular structures.
Henri-François Renard, Mijo Simunovic, Joël Lemière et al. | mTORC1-mediated translational elongation limits intestinal tumour initiation and growth
The mTORC1 complex has been implicated in tumorigenesis owing partially to its ability to increase protein translation; now, mTORC1 activity in the mouse intestine is shown not to be required for normal homeostasis but to be necessary for the triggering of tumorigenesis by APC mutations, suggesting that it could be a good target for the prevention of colorectal cancer in high-risk patients.
William J. Faller, Thomas J. Jackson, John R. P. Knight et al. | Compositional engineering of perovskite materials for high-performance solar cells
Inorganic–organic lead halide perovskite could be efficient when used as the light-harvesting component of solar cells; here incorporation of methylammonium lead bromide into formamidinium lead iodide stabilizes the perovskite and improves the power conversion efficiency of the solar cell up to 17.9 per cent.
Nam Joong Jeon, Jun Hong Noh, Woon Seok Yang et al. | IgG1 protects against renal disease in a mouse model of cryoglobulinaemia
Here, the predominant murine immunoglobulin G subclass, IgG1, which is a poor activator of effector mechanisms, is shown to have a regulatory function, protecting against the development of IgG3 immune-complex-driven renal disease by competing with IgG3 for antigen and increasing immune complex solubility.
Richard T. Strait, Monica T. Posgai, Ashley Mahler et al. | Structure of the immature HIV-1 capsid in intact virus particles at 8.8 Å resolution
Cryo-electron tomography and subtomogram averaging methods reveal the structure of the capsid lattice within intact heterogeneous immature HIV-1 particles.
Florian K. M. Schur, Wim J. H. Hagen, Michaela Rumlová et al. | | | | |
No comments:
Post a Comment