Research articles

Tissue regeneration is of great interest; however the number of times a given tissue can regenerate is unknown. Now, Eguchiet al. demonstrate that the lens of the Japanese newt—Cynops pyrrhogaster—can regenerate 18 times over a 16-year period, and that the new lenses are similar to those of control adult animals.

Thioredoxin reductase 1 is a flavoprotein that is involved in the regulation of redox homeostasis. Fritz-Wolfet al. report the first crystal structures of thioredoxin reductase 1 in complex with its substrate, thioredoxin, and confirm that the enzyme uses a flexible carboxy-terminal arm for electron transport to its substrates.

Group-1 influenza A neuramidase proteins have a 150-cavity that can be targeted by drugs, but the 2009 H1N1 virus neuramidase is not thought to have a 150-cavity. Here, biophysical simulations show that the 2009 H1N1 neuramidase exists in solution with an open 150-cavity, which is stabilized by a salt bridge.

During development, Wnt-mediated Notch signalling controls the generation of somites from the presomitic mesoderm, but the precise signalling mechanism is unknown. Here, the transcription factor Mesogenin 1 is shown to be a direct target of Wnt3a and regulates the transcription of a Notch signalling program.

The torsinA protein localizes to the endoplasmic reticulum and, when mutated, causes early onset torsion dystonia. The authors reveal a new role for torsinA in proteosome-mediated degradation of misfolded proteins, and relate this to endoplasmic reticulum stress, in aCaenorhabditis elegansmodel and patient fibroblasts.

von Willebrand factor (VWF) multimers mediate primary adhesion and aggregation of platelets. Jakobiet al. reveal a calcium-binding site in the VWF-A2 domain, and show that calcium binding encourages folding of the protein and has a role in mechanosensing.

Studying how pathogens enter polarized epithelial cells is important for understanding infection. Here, activation of chemokine receptors on the apical membrane of epithelial cells, is shown to engage Src family tyrosine signalling, resulting in relocation of the viral co-receptor αvβ3 to the apical membrane and adenovirus entry.

Soluble cytosolic proteins can be degraded in lysosomes by chaperone-mediated autophagy, however, the current method to measure this process requires isolation of lysosomes. Now, a fluorescent reporter is described that can measure this type of autophagy in intact cells.

A quantum simulator can follow the evolution of a prescribed model, whose behaviour may be difficult to determine. Here, the emergence of magnetism is simulated by implementing a quantum Ising model, providing a benchmark for simulations in larger systems.

Two-qubit operation is an essential part of quantum computation, but implementation has been difficult. Gotoet al.introduce optically controllable internuclear coupling in semiconductors providing a simple way of switching inter-qubit couplings in semiconductor-based quantum computers.

Interactions between charge, orbital and lattice degrees of freedom in correlated electron systems have resulted in predictions of new electronic phases of matter. Carlson and Dahmen propose two protocols for detecting disordered electron nematics in condensed matter systems using non-equilibrium methods.

Studies of male genitalia show patterns of divergent evolution, whereas females have been less well studied. Using experimental evolution and quantitative genetic analysis, Simmons and Garcia-Gonzalez show that sexual selection drives the coevolution of female and male genital morphology in the dung beetleOnthophagus taurus.

The construction of three-dimensional hierarchical heterostructures can lead to improved electrochemical properties. Maiet al. synthesize a three-dimensional multicomponent oxide, MnMoO₄/CoMoO₄, which is used to produce a supercapacitor with enhanced performance.

The sigma-2 receptor is used as a biomarker for tumour cell proliferation but its identity is unknown. Using a novel radiolabelled probe, the authors identify progesterone receptor membrane component 1, which is overexpressed in several tumour types, as the putative sigma-2 receptor.

Archaea are microorganisms that use a wide range of carbon and energy sources. Grahamet al. describe an archaeal consortium that can grow at temperatures above 90 °C using crystalline cellulose as a carbon source, with potential applications in enzymatic degradation under extreme conditions.

Ambient levels of the neurotransmitter GABA tonically activate GABA_A. Song et al.show that GABA can have both excitatory and inhibitory effects on hippocampal interneurons and find that low levels of GABA-mediated conductance are excitatory, whereas higher levels result in shunting inhibition.

Hagfish, a group of extant jawless fish, lack true vertebrae, but it is not clear if hagfish lack all vertebrata-like structures. Here the authors report the presence of vertebra-like cartilages in the in-shore hagfish, suggesting that the hagfish underwent secondary reduction of vertebra.

Glucose biofuel cells can be used to produce clean energy from renewable sources, but their use is limited by poor stability and low power output. In this study, bioelectrodes are fabricated using carbon nanotubes and the resulting biofuel cells have improved stability and power.

The unoccupied electronic levels of graphene are modified by corrugation, doping and presence of impurities. Here, the authors map discrete electronic domains within a single graphene sheet using scanning transmission X-ray microscopy and provide insight into the modification of unoccupied levels.

Mutations in the DNA helicaseBLM cause Bloom syndrome, which is characterized by slow replication fork progression and genetic instability. Here, cells lacking BLMare shown to have a defect in cytidine deaminase, which alters the pyrimidine pool and results in replication fork progression with altered velocity.