Articles

MicroRNAs bind to the 3′-untranslated region of genes to regulate expression. In this study, an RNA-binding protein, RMB38, is shown to selectively regulate the access of some microRNAs to their targets, and control the expression of some p53 target genes.

Intercalating alkali metals into picene—a hydrocarbon with five linearly fused benzene rings—results in superconducting materials. Now, alkali-metal-doped phenanthrene, which consists of three fused benzene rings, is also found to be superconducting, opening up a broader class of organic superconductors.

Biological digital sensors require the fabrication of modular genetic logic gates. Using thePseudomonas syringae hrpsystem, Wang and colleagues generate AND, NOT and NAND gates, demonstrating the ability to engineer a modular system from biological elements.

In the theory of general relativity time flows at different rates depending on the space–time geometry. Here, a drop in the visibility of a quantum 'clock' interference in a gravitational potential is predicted, which cannot be explained without the general relativistic notion of time.

During cell division, a cytoplasmic bridge—the midbody—forms between the nascent daughter cells, but it has been unclear under which conditions this is retained by a daughter cell or released. Now, Ettinger and colleagues show that midbody-release occurs more frequently in stem cells compared with cancer cells.

Memory retrieval followed by extinction training has been shown to erase fear memories. Flavellet al. show that this approach also erases appetitive memories in rats and results from a modification of memory reconsolidation, which could be useful for the treatment of drug addiction.

Nanofluidic diodes are utilized for the rectification of ionic transport, but their rectifying properties cannot be altered after the devices are made. Here, a field-effect reconfigurable nanofluidic diode is reported in which the forward direction and the degree of rectification can be modulated by a gate voltage.

The interfaces between complex oxides can play host to a range of interesting electronic phenomena. Xieet al. demonstrate that the electronic properties at the LaAlO₃/SrTiO₃interface can be tuned upon application of common polar solvents such as acetone, ethanol and water.

Hoop-shaped aromatic hydrocarbons can be considered as finite models of single-wall carbon nanotubes. Hitosugiet al. describe the bottom-up synthesis of a macrocyclic tetramer of chrysene, and show that its persistent rotational isomers are finite models of chiral nanotubes.

The Early Palaeoproterozoic saw glaciations and a rise in atmospheric oxygen, but the link between these two changes is poorly understood. Here, osmium isotope records from sedimentary rocks indicate synchronicity between an episode of increasing oxygen and a glacial transition.

Molecular probes that can detect aqueous sulphides could help to elucidate their roles in biological signalling. Qianet al. develop two sulphide-selective fluorescent probes and demonstrate their ability to image free sulphide in living cells.

In non-NMDA glutamate receptors, intersubunit contacts within agonist binding domains affect functional desensitization. Now, NMDA receptor activation, but not desensitization, is shown to involve rearrangements at the heterodimer interface, suggesting that the intersubunit contacts of NMDA and non-NMDA receptors may have distinct functional roles.

The Golgi membrane is fragmented during mitosis and is subsequently fused following cell division and this process is known to be controlled by ubiquitination. In this study, the ubiquitin ligase HACE1 is shown to be targeted to the Golgi membrane and is required for fusion after the completion of mitosis.

Radiomitigating compounds could be used to protect against ionizing radiation. In this study, mitochondria-targeted oleic and stearic acid derivatives are shown to inhibit pro-apoptotic oxidative events, prevent cell death, and protect mice against lethal doses of radiation.

Ampullary organs are involved in electroreception, but whether these are derived from placodes, thickened ectoderm, is unclear. In this study, the ampullary organs of the primitive ray-finned fish,Polyodon spathula, are shown to develop from lateral line placodes, suggesting that this is the ancestral state in bony fishes.

The folding of multidomain proteins can involve metastable intermediate states. Here, a single-molecule FRET based method is developed and used to identify six metastable states in the folding landscape of the three-domain protein adenylate kinase.

During development, waves of gene expression are required for segmentation of the body axis. In this study, repeated splitting of a wave of hedgehog gene expression is shown during segmentation of the spiderAchaearanea tepidariorum.

The fusion of satellite cells to muscle fibres during adult life is required for both muscle growth and regeneration but it is unknown whether non-muscle cells contribute to this process. Now, Dellavalle and colleagues show that pericytes, cells associated with the vasculature can contribute to both growth and regeneration of muscle fibres.

Modelling of chaos and oscillations is usually done indirectly and quantitatively by fitting models to a finite number of data-points. Here, a qualitative framework is developed where the characteristics of the underlying dynamical system are directly specified, revealing new properties of such systems.

The generation of human cell lines using somatic cell nuclear transfer has been difficult to achieve. In this study, Egliet al. show that while mouse eggs reprogram somatic cells within hours, human eggs arrest after nuclear transfer which may be due to a lack of genome transcription.