Articles in 2007

A new computational approach that can be used to refine the three dimensional structural models of proteins is described. When used to refine models generated from nuclear magnetic resonance data, the method can improve the accuracy of the structures in terms of the backbone conformations and the placement of core side chains. In addition, the approach can be used to generate significantly better solutions to the X-ray crystallographic phase problem in molecular replacement trials.

The Lgr5 (also known as Gpr49) gene is identified as a unique, single marker gene for adult stem cells and provides the first lineage tracing data for long-lived pluripotent stem cells in the small intestine and colon. These findings will have great impact on stem cell and cancer research.

With the increasing availability of genomic sequences, it is possible to ask questions about evolution by examining closely related species and genes. This paper shows that the well-studied GAL3 and GAL1 genes in yeast evolved from one ancestral gene, via movement of transcriptional regulatory sites after a gene duplication event.

When John Maddox took over the reins of Nature's editorship in 1966, the journal was in urgent need of reform. Walter Gratzer reflects on how Maddox and his successor (and predecessor) David Davies steered the magazine into its modern format.

During the editorship of Philip Campbell (1995 onwards), the single author has all but disappeared. As the average number of contributors to individual papers continues to rise, Mott Greene investigates whether the present system is likely to last.

The co-editorship of A. J. V. Gale and L. J. F. Brimble (1938–61) oversaw milestone publications on human origins. Bill Bynum unearths a treasure trove of palaeoanthropology in post-war Nature.

Nature under the editorship of Sir Richard Gregory (1919–39) was banned in Nazi Germany. Uwe Hossfeld and Lennart Olsson explore the clash between science and national socialism.

The editorship of David Davies (1973–1980) saw global nuclear arsenals grow and India join the nuclear club. Frank Barnaby examines how Davies addressed the cold war arms race in Nature.

Publisher Alexander Macmillan chose Norman Lockyer as Nature's founding Editor in 1869. It was an inspired choice, but Lockyer's powerful personality courted controversy in the fledgling magazine. Ruth Barton investigates.

Engrafted mesenchymal stem cells (MSCs) promote breast cancer metastasis formation. Breast cancer cells induce MSCs to produce the cytokine CCL5, which then acts on breast tumour cells, enhancing their ability to migrate and extravasate blood vessel at the site of future metastases.

A test-bed system for examining how development guides evolutionary change is the arrangement of molars in mice. The first molar is larger than the one behind, which is in turn larger than the third, hindmost molar. Experimental investigations have shown that molar development follows an inhibitory cascade model, and the results are used to show how this simple model governs the variation in molar size and number in rodent evolution.

miR-10b is highly expressed in aggressive human breast cancers and mediates breast cancer cell migration, invasion and metastasis. miR-10b is transcriptionally activated by Twist and exerts its effects by regulating the target genes HOXD10 and RHOC.

Some proteins are degraded by a process called the N-end rule, in which a non-templated amino acid is added to the amino terminus as a marker for degradation. A set of crystal structures of the enzyme that promotes transfer of the amino acid along with the charged donor tRNA is solved in the presence or absence of target peptide. The results reveal that peptide bond formation occurs differently than on the ribosome.

The primitive hominins from Dmanisi in the Republic of Georgia are often thought to be akin to Homo erectus and are arguably the earliest known members of the human family outside Africa. This conclusion has come, so far, from the presentation of postcranial material: now a partial skeleton of an adolescent individual associated with a skull, and remains from three adult individuals, suggest that the Dmanisi hominids are even more primitive than that, akin to Homo habilis.

It is thought that the abundance of ⁴⁰Ar in the atmosphere represents the time-integrated loss of gases from the interior through partial melting in the mantle followed by melt ascent to the surface and gas exsolution. But data now presented reveal two major difficulties with this simple magmatic degassing scenario: that argon is compatible in the major phases of the terrestrial planets and that argon diffusion in these phases is slow at upper-mantle conditions.

Acid-sensing ion channels belong to a large family of ion channels, the diverse functions of which range from sodium absorption to mechanosensitivity; however, the structure of this class of proteins is unknown. Here, the high-resolution crystal structure of chicken ASIC1 in the closed state is reported, and of note is the trimeric architecture and the appealing mechanism of proton-gating proposed.

A lasing effect with a single artificial atom (a Josephson-junction charge qubit) that is embedded in a superconducting resonator is demonstrated, making use of the property that such artificial atoms are strongly and controllably coupled to resonator modes. The device is essentially different from existing lasers and masers; one and the same artificial atom excited by current injection produces many photons.

Plasmacytoid dendritic cells (pDCs) produce type 1 interferon in response to viral infection and activation of endosomal Toll-like receptors. This paper shows that in psoriatic skin pDC TLR-9 is activated by an antimicrobial peptide in complex with endogenous human DNA that is released from dying cells.

Two JmjC-domain-contain ing enzymes are shown to catalyse demethylation of histone H3K27me3, a histone modification mediated by polycomb proteins and associated with stem cell maintenance and differentiation.

The impact flux from kilometre-sized bodies has increased by at least a factor of two over the long-term average during the last ∼100 Myr. This surge probably was triggered by the catastrophic disruption of the parent body of the asteroid Baptistina, which broke up in the inner main asteroid belt. Fragments evolved to orbits where they could strike the terrestrial planets.