Research articles

A study of endocytosis of Shigella toxin shows that it enters cells via narrow tubular membrane invaginations, with similar properties on cell and model membranes. The toxin induces membrane reorganisation before the formation of tubular invaginations.

It is shown for the first time that a vertebrate-specific member of the TATA-box-binding protein (TBP) family, called TRF3, controls haematopoiesis in zebrafish embryogenesis.

The ciliate Oxytricha trifallax cuts up and removes most of its nuclear DNA during one developmental stage, stitching 5% of its chromosomes back together at specific points. This paper demonstrates that maternal RNA remaining in the new cell could serve as a template for the chromosomal rearrangements, as shown by the disruption of proper assembly when several RNAs are removed from the cell.

This study presents the first large scale transcriptional analysis of malaria parasites isolated from human patients, and defines three distinct transcriptional patterns that can be described as active growth, response to starvation and environmental stress response.

A relatively new imaging technique is used to reveal that some Cretaceous gymnosperm seeds have evolutionary links with Gnetales (an evolutionarily hard-to-place gymnosperm group with three living genera) and the Bennetitales (an extinct group of cycad-like plants). The link between Gnetales and Bennetitales may have important consequences for our understanding of the evolution of seed plants, including flowering plants.

The use of time series data from 522 remote lakes and streams in North America and northern Europe and a simple model shows that dissolved organic carbon concentrations between 1990– 2004 have increased in proportion to the rates at which atmospherically deposited anthropogenic sulphur and sea salt have declined. It is suggested that acid deposition to these ecosystems has been partially buffered by changes in organic acidity and that the rise in dissolved organic carbon is integral to recovery from acidification.

The discovery of several white dwarfs with atmospheres primarily composed of carbon, with little or no trace of hydrogen or helium is reported. These stars do not fit satisfactorily in any of the currently known theories of post-asymptotic giant branch evolution.

The key to successful social interactions is the ability to accurately assess others' intentions, be they friend or foe. In humans, this ability is present very early on in life, as is shown here when preverbal infants evaluate individuals based on their actions towards others, preferring helpers to neutral or hindering individuals.

The observation of a negative Hall resistance in the magnetic-field-induced normal state of underdoped 'YBCO'materials, which reveals that these pockets are electron-like rather than hole-like. It is proposed that these electron pockets most probably arise from a reconstruction of the Fermi surface caused by the onset of a density-wave phase, as is thought to occur in the electron-doped copper oxides near the onset of antiferromagnetic order.

A microcavity structure to which a periodic potential is applied has been designed, which effectively creates an array of weakly-coupled condensates. This allows the observation of fundamental dynamic behaviour, namely the build-up of certain superfluid-like states, which has been predicted for arrays of atomic Bose–Einstein condensates, but not yet observed.

A drug used as an antidepressant in humans increases Caenorhabditis elegans lifespan. In humans, this drug blocks neural signalling by the neurotransmitter serotonin. In C. elegans, it seems to act as an antagonist for the serotonin receptor and for the receptor of the neurotransmitter octopamine. The drug's effect on lifespan seems to involve mechanisms similar to those that underlie lifespan extension by dietary restriction.

LHCII, the main light-harvesting complex in photosynthesis, has an inbuilt capability to undergo transformation into a dissipative state by conformational change, but it was not known if such events occur in vivo or how energy is dissipated in this state. The transition into the dissipative state is associated with a twist in the configuration of the LHCII-bound carotenoid neoxanthin identified using resonance Raman spectroscopy. Applying this technique to study isolated chloroplasts and whole leaves, this paper shows that the same change in neoxanthin configuration occurs in vivo, to an extent consistent with the magnitude of energy dissipation.

The crystal structure of the maltose transporter, in complex with its periplasmic maltose-binding protein, at 2.8 Å resolution is presented. Because both ATP and maltose are bound and a mutation that prevents ATP hydrolysis has been introduced, the complex has been captured in an intermediate state and a mechanism for maltose transport proposed.

Regulatory T cells suppress immune function by direct cell to cell contact and secretion of the cytokines IL-10 and TGF-β. In this paper, a novel member of the IL-12 cytokine family that contributes to Treg function is identified.

The crystal structure of a SNARE protein bound to a clathrin adaptor is reported, which reveals that there is highly specific interactions between two folded domains as opposed to the linear peptide motif or folded domains that have been described for other families of cargo proteins. This is the first example of a SNARE association with a clathrin adaptor and describes a novel mechanism by which cargo can be recruited into clathrin coated vesicles.