A vital dependence on genetically modified organisms on an artificial nutrient could be a means of preventing their escape into the environment.
A concerted focus on soils will benefit society in untold ways and should be embraced.
The discovery of Beagle 2 on Mars should spur the search for other items lost to science.
Erratic human behaviour and incomplete information plague efforts to model risk.
Studies raise prospect of intervention in the radicalization process.
Thought to make up the Universe’s missing matter, WIMPs are running out of places to hide.
Engineered bacteria kept in check with a designer diet.
Meteorologists investigate airborne jets that bring both floods and drought relief.
By splicing animals together, scientists have shown that young blood rejuvenates old tissues. Now, they are testing whether it works for humans.
By firing lasers into the sky, Claire Max has transformed the capabilities of current — and future — telescopes.
News & Views
Gold in the +3 oxidation state is scarcely used in catalysis, because the oxidants employed to generate it can damage reactants. An oxidant-free route to gold(III) catalysts reveals their potential. See Article p.449
The discovery and functional analysis of the protein MEIKIN in mice leads to an evolutionarily conserved model of how chromosome segregation is regulated during a specialized type of cell division called meiosis I. See Article p.466
A screen of 10,000 bacterial strains, cultured in their normal soil, has uncovered an antibiotic with broad and potent activity. And because the compound targets lipid molecules, developing resistance is probably difficult. See Article p.455
It emerges that most of the elements heavier than helium are not found in galaxies, where they can be mixed into future stars and planets. Instead, these elements largely reside far from galaxies in ionized gas and dust particles.
A simplified global climate model that keeps track of water as it moves through Earth's water cycle throws fresh light on how the Asian summer monsoon has varied during the past 150,000 years.
Endocytosis is a process by which molecules gain access to a cell. An unusual mode of endocytosis has now been shown to regulate cell signalling, and to be highjacked by bacterial toxins. See Article p.460 & Letter p.493
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Human immunodeficiency virus type 1 (HIV-1) assembly proceeds in two stages. First, the 55 kilodalton viral Gag polyprotein assembles into a hexameric protein lattice at the plasma membrane of the infected cell, inducing budding and release of an immature particle. Second, Gag is cleaved by the viral protease, leading to internal rearrangement of the virus into the mature, infectious form. Immature and mature HIV-1 particles are heterogeneous in size and morphology, preventing high-resolution analysis of their protein arrangement in situ by conventional structural biology methods. Here we apply cryo-electron tomography and sub-tomogram averaging methods to resolve the structure of the capsid lattice within intact immature HIV-1 particles at subnanometre resolution, allowing unambiguous positioning of all α-helices. The resulting model reveals tertiary and quaternary structural interactions that mediate HIV-1 assembly. Strikingly, these interactions differ from those predicted by the current model based on in vitro-assembled arrays of Gag-derived proteins from Mason–Pfizer monkey virus. To validate this difference, we solve the structure of the capsid lattice within intact immature Mason–Pfizer monkey virus particles. Comparison with the immature HIV-1 structure reveals that retroviral capsid proteins, while having conserved tertiary structures, adopt different quaternary arrangements during virus assembly. The approach demonstrated here should be applicable to determine structures of other proteins at subnanometre resolution within heterogeneous environments.
Structural and biochemical studies show that the biosynthesis of the food preservative nisin involves the tRNA-dependent glutamylation of serine and threonine.
X-ray crystallography and EPR spectroscopy are used to characterize a soluble, oxygen-tolerant reductive dehalogenase from Nitratireductor pacific us 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.