Tags : nature | protein | human

Nature
Sat Jun 27 20:41:00 EDT 2009
Home: http://www.nature.com/nature/current_issue/
Feed: http://www.nature.com/nature/current_issue/rss/index.html

Making the paper: Dewashish Upadhyay - Ancient rocks bear traces of Earth's tumultuous early years.

Abstractions - Last authorPeople with Down's syndrome, a disorder caused by having an extra copy of all or part of chromosome 21, tend to have lower-than-average cognitive ability and several characteristic physical features, as well as a shorter lifespan. But, much to the puzzlement of scientists,

From the blogosphere - Academic reports may sound alarm bells, but do not necessarily spur governments into action. In a post on Indigenus, Nature India editor Subhra Priyadarshini highlights two recent publications on the effects of climate change on vulnerable human populations (http://tinyurl.com/nqvq3t).A report produced

Cheerleader or watchdog? - Science journalism is under threat. What can scientists do to help?

Raising the standards - A fledgling effort in China will show people what is happening on the environmental front.

Orphan giant - Strong advocacy is needed if progress is to be made against tuberculosis.

Animal biology: Birds of a feather - PLoS Biol.7, e1000132 (2009) 10.1371/journal.pbio.1000132The size of flighted birds is limited by the demands of feather maintenance.Sievert Rohwer at the University of Washington in Seattle and his colleagues studied 43 species of bird, assessing size, the length of

Astronomy: Honing the Hubble constant - Astrophys. J.699, 539–563 (2009) 10.1088/0004-637X/699/1/539Astronomers have measured the Universe's current rate of expansion to within 5% — twice as a precisely as before. Adam Riess of the Space Telescope Science Institute in Baltimore, Maryland, and his team

Neurobiology: Sweet memories - BMC Biol.7, 30 (2009) 10.1186/1741-7007-7-30Honeybees have helped scientists to sniff out a trigger of long-term memory formation. Calcium has been linked to this type of memory for more than a decade, but only recently have researchers directly manipulated it

Chemistry: The tiniest acid drop - Science324, 1545–1548 (2009) 10.1126/science.1171753The smallest drop of acid it is possible to make has been spotted within superfluid helium nanodrops cooled to below 1 kelvin.Martina Havenith of Ruhr University Bochum in Germany and her colleagues observed

Nanotechnology: Mass spec goes mechanical -

Atmospheric science: Rain on physics -

Biology: A light touch - Science324, 1580–1582 (2009) 10.1126/science.1172890Merkel cells were discovered in the late nineteenth century and have long been suspected of playing a part in sensing light touch. However, this has never been entirely settled experimentally.Ellen Lumpkin and Huda

Organic chemistry: Give and take -

Genetics: Depression link revoked - J. Am. Med. Assoc.301, 2462–2471 (2009)An analysis of the literature affirms doubts about a much-hailed gene–environment link for depression.In 2003, researchers found that individuals with specific versions of the serotonin receptor gene 5-HTTLPR are more susceptible to depression when challenged

Cognitive science: The tool becomes him -

Journal club - A physicist peels back the layers of excitement about graphene.Graphene is an atom-thick sheet of carbon in which electrons behave as if they have no mass. Atomic carbon layers have been grown epitaxially — that is, perfectly aligned with atoms in an underlying crystal

Interrogation: hard for psychologists to act as whistleblowers - SirI was disappointed in your Editorial 'Responsible interrogation' (

Interrogation: our professional body forbids involvement - SirYour Editorial 'Responsible interrogation' (

Free will: it's a normal biological property, not a gift or a mystery - SirIn his Essay 'Is free will an illusion?' (Nature459, 164–165; 2009), Martin Heisenberg argues that humans must have free will because freedom of action has been demonstrated in other animals — including those as small as fruitflies

Free will: emotions and consciousness could contribute - SirIn his Essay 'Is free will an illusion?' (Nature459, 164–165; 2009), Martin Heisenberg suggests that belief in free will is supported by quantum events. However, the concept of free will may become confused if it is linked

How air capture could help to promote a Copenhagen solution - SirYour News Feature 'Sucking it up' (Nature458, 1094–1097; 2009) reports on the issue of the capture of carbon dioxide from air. This is timely, as in February this year, President Obama and the Canadian Prime Minister, Stephen Harper, agreed to

Planck's power lies in its unique instrument combination - SirYour News Feature 'The test of inflation' (Nature458, 820–824; 2009) highlights some of the exciting scientific data to be collected by the European Space Agency's Planck spacecraft, and the theoretical issues underlying its objectives to study the moments after the

Science journalism: Toppling the priesthood - In the first of three essays, Toby Murcott argues that the process of science needs to be opened up if journalists are to provide proper critique.

Science journalism: Too close for comfort - In the second of three essays, Boyce Rensberger tracks the progression of scientific correspondents from cheerleaders to watchdogs.

Science journalism: The Arab boom - As research increases in Arab countries, the media is stepping up to report on it. In the third of three essays, Nadia El-Awady says the local journalism has much room for improvement.

From rubber ducks to ocean gyres - The tale of Curtis Ebbesmeyer's use of beachcombing to reveal patterns of ocean circulation conveys the romance of early marine science, but his lessons for today are serious, finds Simon Boxall.

Cooking debate goes off the boil - Richard Wrangham's new book is an expansion of a provocative hypothesis about human history that he and his colleagues first published in 1999. Cleverly evoking anthropologist Claude Lévi-Strauss's work The Raw and the Cooked, the article was entitled 'The Raw and the Stolen: Cooking

Our changing body image - A gleaming transparent head, studded with stainless-steel screws and embedded with microchips, sits immovable on its plinth. Unnervingly, its left eye looks real: lidless, it flickers in mute appeal as if someone were trapped inside. The Head of the Blue Chip II by Dianne

Science journalism: From the newsroom - The Washington Post's national environmental reporter Juliet Eilperin and its executive editor Marcus Brauchli discuss the future of science coverage in their newspaper.

Structural biology: Protein dynamics from disorder - The functions of proteins are often crucially dependent on how they move, but measuring the absolute magnitudes of protein motions hasn't been possible. A spectroscopic method looks set to change all that.

Granular media: Structures in sand streams - An ingenious experiment that involves dropping a costly, high-speed video camera from a height of several metres reveals how free-falling streams of granular matter, such as sand, break up into grain clusters.

Cell biology: A score for membrane fusion - Intracellular membrane fusion has been mimicked in vitro using a mix of 17 purified proteins and lipid bilayers. This technical tour de force allows the study of how cells orchestrate and perform such fusion events.

50 & 100 years ago - 50 Years agoIn 1956, as an experiment, an agency was started in the London area to put women graduates in touch with any suitable part-time work ... Many potential employers are prejudiced against part-time workers; it was felt that they might have more confidence

Planetary science: Enceladus with a grain of salt - The observation that water plumes erupt from cracks on Saturn's moon Enceladus has fired speculation about a possible subsurface ocean. The latest searches for sodium salts point to the existence of such an ocean.

Stem cells: The stress of forming blood cells - The first heartbeat is an important moment in an embryo's life. The biomechanical forces created by pulsatile flow promote the formation of haematopoietic stem cells that equip the body with its mature blood cells.

Nuclear physics: Unexpected doubly magic nucleus - Nuclei with a 'magic' number of both protons and neutrons, dubbed doubly magic, are particularly stable. The oxygen isotope 24O has been found to be one such nucleus — yet it lies just at the limit of stability.

Recent advances and emerging trends in plant hormone signalling - Plant growth and development is regulated by a structurally unrelated collection of small molecules called plant hormones. During the last 15 years the number of known plant hormones has grown from five to at least ten. Furthermore, many of the proteins involved in plant hormone signalling pathways have been identified, including receptors for many of the major hormones. Strikingly, the ubiquitin–proteasome pathway plays a central part in most hormone-signalling pathways. In addition, recent studies confirm that hormone signalling is integrated at several levels during plant growth and development.

A soma-to-germline transformation in long-lived Caenorhabditis elegans mutants - Unlike the soma, which ages during the lifespan of multicellular organisms, the germ line traces an essentially immortal lineage. Genomic instability in somatic cells increases with age, and this decline in somatic maintenance might be regulated to facilitate resource reallocation towards reproduction at the expense

GOLPH3 modulates mTOR signalling and rapamycin sensitivity in cancer - Genome-wide copy number analyses of human cancers identified a frequent 5p13 amplification in several solid tumour types, including lung (56%), ovarian (38%), breast (32%), prostate (37%) and melanoma (32%). Here, using integrative analysis of a genomic profile of the region, we identify a Golgi protein,

Reconstitution of Rab- and SNARE-dependent membrane fusion by synthetic endosomes - Rab GTPases and SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) are evolutionarily conserved essential components of the eukaryotic intracellular transport system. Although pairing of cognate SNAREs is sufficient to fuse membranes in vitro, a complete reconstitution of the Rab–SNARE machinery has never been

Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus - Saturn's moon Enceladus emits plumes of water vapour and ice particles from fractures near its south pole, suggesting the possibility of a subsurface ocean. These plume particles are the dominant source of Saturn’s E ring. A previous in situ analysis of these particles concluded that the minor organic or siliceous components, identified in many ice grains, could be evidence for interaction between Enceladus’ rocky core and liquid water. It was not clear, however, whether the liquid is still present today or whether it has frozen. Here we report the identification of a population of E-ring grains that are rich in sodium salts (∼0.5–2% by mass), which can arise only if the plumes originate from liquid water. The abundance of various salt components in these particles, as well as the inferred basic pH, exhibit a compelling similarity to the predicted composition of a subsurface Enceladus ocean in contact with its rock core. The plume vapour is expected to be free of atomic sodium. Thus, the absence of sodium from optical spectra is in good agreement with our results. In the E ring the upper limit for spectroscopy is insufficiently sensitive to detect the concentrations we found.

No sodium in the vapour plumes of Enceladus - The discovery of water vapour and ice particles erupting from Saturn’s moon Enceladus fuelled speculation that an internal ocean was the source. Alternatively, the source might be ice warmed, melted or crushed by tectonic motions. Sodium chloride (that is, salt) is expected to be present in a long-lived ocean in contact with a rocky core. Here we report a ground-based spectroscopic search for atomic sodium near Enceladus that places an upper limit on the mixing ratio in the vapour plumes orders of magnitude below the expected ocean salinity. The low sodium content of escaping vapour, together with the small fraction of salt-bearing particles, argues against a situation in which a near-surface geyser is fuelled by a salty ocean through cracks in the crust. The lack of observable sodium in the vapour is consistent with a wide variety of alternative eruption sources, including a deep ocean, a freshwater reservoir, or ice. The existing data may be insufficient to distinguish between these hypotheses.

Optically controlled locking of the nuclear field via coherent dark-state spectroscopy - A single electron or hole spin trapped inside a semiconductor quantum dot forms the foundation for many proposed quantum logic devices. In group III–V materials, the resonance and coherence between two ground states of the single spin are inevitably affected by the lattice nuclear spins through the hyperfine interaction, while the dynamics of the single spin also influence the nuclear environment. Recent efforts have been made to protect the coherence of spins in quantum dots by suppressing the nuclear spin fluctuations. However, coherent control of a single spin in a single dot with simultaneous suppression of the nuclear fluctuations has yet to be achieved. Here we report the suppression of nuclear field fluctuations in a singly charged quantum dot to well below the thermal value, as shown by an enhancement of the single electron spin dephasing time T2*, which we measure using coherent dark-state spectroscopy. The suppression of nuclear fluctuations is found to result from a hole-spin assisted dynamic nuclear spin polarization feedback process, where the stable value of the nuclear field is determined only by the laser frequencies at fixed laser powers. This nuclear field locking is further demonstrated in a three-laser measurement, indicating a possible enhancement of the electron spin T2* by a factor of several hundred. This is a simple and powerful method of enhancing the electron spin coherence time without use of ‘spin echo’-type techniques. We expect that our results will enable the reproducible preparation of the nuclear spin environment for repetitive control and measurement of a single spin with minimal statistical broadening.

High-speed tracking of rupture and clustering in freely falling granular streams - Thin streams of liquid commonly break up into characteristic droplet patterns owing to the surface-tension-driven Plateau–Rayleigh instability. Very similar patterns are observed when initially uniform streams of dry granular material break up into clusters of grains, even though flows of macroscopic particles are considered to lack surface tension. Recent studies on freely falling granular streams tracked fluctuations in the stream profile, but the clustering mechanism remained unresolved because the full evolution of the instability could not be observed. Here we demonstrate that the cluster formation is driven by minute, nanoNewton cohesive forces that arise from a combination of van der Waals interactions and capillary bridges between nanometre-scale surface asperities. Our experiments involve high-speed video imaging of the granular stream in the co-moving frame, control over the properties of the grain surfaces and the use of atomic force microscopy to measure grain–grain interactions. The cohesive forces that we measure correspond to an equivalent surface tension five orders of magnitude below that of ordinary liquids. We find that the shapes of these weakly cohesive, non-thermal clusters of macroscopic particles closely resemble droplets resulting from thermally induced rupture of liquid nanojets.

Enhanced carbon pump inferred from relaxation of nutrient limitation in the glacial ocean - The modern Eastern Equatorial Pacific (EEP) Ocean is a large oceanic source of carbon to the atmosphere. Primary productivity over large areas of the EEP is limited by silicic acid and iron availability, and because of this constraint the organic carbon export to the deep ocean is unable to compensate for the outgassing of carbon dioxide that occurs through upwelling of deep waters. It has been suggested that the delivery of dust-borne iron to the glacial ocean could have increased primary productivity and enhanced deep-sea carbon export in this region, lowering atmospheric carbon dioxide concentrations during glacial periods. Such a role for the EEP is supported by higher organic carbon burial rates documented in underlying glacial sediments, but lower opal accumulation rates cast doubts on the importance of the EEP as an oceanic region for significant glacial carbon dioxide drawdown. Here we present a new silicon isotope record that suggests the paradoxical decline in opal accumulation rate in the glacial EEP results from a decrease in the silicon to carbon uptake ratio of diatoms under conditions of increased iron availability from enhanced dust input. Consequently, our study supports the idea of an invigorated biological pump in this region during the last glacial period that could have contributed to glacial carbon dioxide drawdown. Additionally, using evidence from silicon and nitrogen isotope changes, we infer that, in contrast to the modern situation, the biological productivity in this region is not constrained by the availability of iron, silicon and nitrogen during the glacial period. We hypothesize that an invigorated biological carbon dioxide pump constrained perhaps only by phosphorus limitation was a more common occurrence in low-latitude areas of the glacial ocean.

142Nd evidence for an enriched Hadean reservoir in cratonic roots - The isotope 146Sm undergoes α-decay to 142Nd, with a half-life of 103 million years. Measurable variations in the 142Nd/144Nd values of rocks resulting from Sm–Nd fractionation could therefore only have been produced within about 400 million years of the Solar System’s formation (that is, when 146Sm was extant). The 142Nd/144Nd compositions of terrestrial rocks are accordingly a sensitive monitor of the main silicate differentiation events that took place in the early Earth. High 142Nd/144Nd values measured in some Archaean rocks from Greenland hint at the existence of an early incompatible-element-depleted mantle. Here we present measurements of low 142Nd/144Nd values in 1.48-gigayear-(Gyr)-old lithospheric mantle-derived alkaline rocks from the Khariar nepheline syenite complex in southeastern India. These data suggest that a reservoir that was relatively enriched in incompatible elements formed at least 4.2 Gyr ago and traces of its isotopic signature persisted within the lithospheric root of the Bastar craton until at least 1.48 Gyr ago. These low 142Nd/144Nd compositions may represent a diluted signature of a Hadean (4 to 4.57 Gyr ago) enriched reservoir that is characterized by even lower values. That no evidence of the early depleted mantle has been observed in rocks younger than 3.6 Gyr (refs 3, 4, 7) implies that such domains had effectively mixed back into the convecting mantle by then. In contrast, some early enriched components apparently escaped this fate. Thus, the mantle sampled by magmatism since 3.6 Gyr ago may be biased towards a depleted composition that would be balanced by relatively more enriched reservoirs that are ‘hidden’ in Hadean crust, the D′′ layer of the lowermost mantle or, as we propose here, also within the roots of old cratons.

Origins and evolutionary genomics of the 2009 swine-origin H1N1 influenza A epidemic - In March and early April 2009, a new swine-origin influenza A (H1N1) virus (S-OIV) emerged in Mexico and the United States. During the first few weeks of surveillance, the virus spread worldwide to 30 countries (as of May 11) by human-to-human transmission, causing the World Health Organization to raise its pandemic alert to level 5 of 6. This virus has the potential to develop into the first influenza pandemic of the twenty-first century. Here we use evolutionary analysis to estimate the timescale of the origins and the early development of the S-OIV epidemic. We show that it was derived from several viruses circulating in swine, and that the initial transmission to humans occurred several months before recognition of the outbreak. A phylogenetic estimate of the gaps in genetic surveillance indicates a long period of unsampled ancestry before the S-OIV outbreak, suggesting that the reassortment of swine lineages may have occurred years before emergence in humans, and that the multiple genetic ancestry of S-OIV is not indicative of an artificial origin. Furthermore, the unsampled history of the epidemic means that the nature and location of the genetically closest swine viruses reveal little about the immediate origin of the epidemic, despite the fact that we included a panel of closely related and previously unpublished swine influenza isolates. Our results highlight the need for systematic surveillance of influenza in swine, and provide evidence that the mixing of new genetic elements in swine can result in the emergence of viruses with pandemic potential in humans.

Down's syndrome suppression of tumour growth and the role of the calcineurin inhibitor DSCR1 - The incidence of many cancer types is significantly reduced in individuals with Down’s syndrome, and it is thought that this broad cancer protection is conferred by the increased expression of one or more of the 231 supernumerary genes on the extra copy of chromosome 21. One such gene is Down’s syndrome candidate region-1 (DSCR1, also known as RCAN1), which encodes a protein that suppresses vascular endothelial growth factor (VEGF)-mediated angiogenic signalling by the calcineurin pathway. Here we show that DSCR1 is increased in Down’s syndrome tissues and in a mouse model of Down’s syndrome. Furthermore, we show that the modest increase in expression afforded by a single extra transgenic copy of Dscr1 is sufficient to confer significant suppression of tumour growth in mice, and that such resistance is a consequence of a deficit in tumour angiogenesis arising from suppression of the calcineurin pathway. We also provide evidence that attenuation of calcineurin activity by DSCR1, together with another chromosome 21 gene Dyrk1a, may be sufficient to markedly diminish angiogenesis. These data provide a mechanism for the reduced cancer incidence in Down’s syndrome and identify the calcineurin signalling pathway, and its regulators DSCR1 and DYRK1A, as potential therapeutic targets in cancers arising in all individuals.

Biomechanical forces promote embryonic haematopoiesis - Biomechanical forces are emerging as critical regulators of embryogenesis, particularly in the developing cardiovascular system. After initiation of the heartbeat in vertebrates, cells lining the ventral aspect of the dorsal aorta, the placental vessels, and the umbilical and vitelline arteries initiate expression of the transcription factor Runx1 (refs 3–5), a master regulator of haematopoiesis, and give rise to haematopoietic cells. It remains unknown whether the biomechanical forces imposed on the vascular wall at this developmental stage act as a determinant of haematopoietic potential. Here, using mouse embryonic stem cells differentiated in vitro, we show that fluid shear stress increases the expression of Runx1 in CD41+c-Kit+ haematopoietic progenitor cells, concomitantly augmenting their haematopoietic colony-forming potential. Moreover, we find that shear stress increases haematopoietic colony-forming potential and expression of haematopoietic markers in the para-aortic splanchnopleura/aorta–gonads–mesonephros of mouse embryos and that abrogation of nitric oxide, a mediator of shear-stress-induced signalling, compromises haematopoietic potential in vitro and in vivo. Collectively, these data reveal a critical role for biomechanical forces in haematopoietic development.

Subcellular homeostasis of phytohormone auxin is mediated by the ER-localized PIN5 transporter - The plant signalling molecule auxin provides positional information in a variety of developmental processes by means of its differential distribution (gradients) within plant tissues. Thus, cellular auxin levels often determine the developmental output of auxin signalling. Conceptually, transmembrane transport and metabolic processes regulate the steady-state levels of auxin in any given cell. In particular, PIN auxin-efflux-carrier-mediated, directional transport between cells is crucial for generating auxin gradients. Here we show that Arabidopsis thaliana PIN5, an atypical member of the PIN gene family, encodes a functional auxin transporter that is required for auxin-mediated development. PIN5 does not have a direct role in cell-to-cell transport but regulates intracellular auxin homeostasis and metabolism. PIN5 localizes, unlike other characterized plasma membrane PIN proteins, to endoplasmic reticulum (ER), presumably mediating auxin flow from the cytosol to the lumen of the ER. The ER localization of other PIN5-like transporters (including the moss PIN) indicates that the diversification of PIN protein functions in mediating auxin homeostasis at the ER, and cell-to-cell auxin transport at the plasma membrane, represent an ancient event during the evolution of land plants.

Yurt, Coracle, Neurexin IV and the Na+,K+-ATPase form a novel group of epithelial polarity proteins - The integrity of polarized epithelia is critical for development and human health. Many questions remain concerning the full complement and the function of the proteins that regulate cell polarity. Here we report that the Drosophila FERM proteins Yurt (Yrt) and Coracle (Cora) and the membrane proteins Neurexin IV (Nrx-IV) and Na+,K+-ATPase are a new group of functionally cooperating epithelial polarity proteins. This ‘Yrt/Cora group’ promotes basolateral membrane stability and shows negative regulatory interactions with the apical determinant Crumbs (Crb). Genetic analyses indicate that Nrx-IV and Na+,K+-ATPase act together with Cora in one pathway, whereas Yrt acts in a second redundant pathway. Moreover, we show that the Yrt/Cora group is essential for epithelial polarity during organogenesis but not when epithelial polarity is first established or during terminal differentiation. This property of Yrt/Cora group proteins explains the recovery of polarity in embryos lacking the function of the Lethal giant larvae (Lgl) group of basolateral polarity proteins. We also find that the mammalian Yrt orthologue EPB41L5 (also known as YMO1 and Limulus) is required for lateral membrane formation, indicating a conserved function of Yrt proteins in epithelial polarity.

Structural insight into the autoinhibition mechanism of AMP-activated protein kinase - The AMP-activated protein kinase (AMPK) is characterized by its ability to bind to AMP, which enables it to adjust enzymatic activity by sensing the cellular energy status and maintain the balance between ATP production and consumption in eukaryotic cells. It also has important roles in the regulation of cell growth and proliferation, and in the establishment and maintenance of cell polarity. These important functions have rendered AMPK an important drug target for obesity, type 2 diabetes and cancer treatments. However, the regulatory mechanism of AMPK activity by AMP binding remains unsolved. Here we report the crystal structures of an unphosphorylated fragment of the AMPK α-subunit (KD-AID) from Schizosaccharomyces pombe that contains both the catalytic kinase domain and an autoinhibitory domain (AID), and of a phosphorylated kinase domain from Saccharomyces cerevisiae (Snf1-pKD). The AID binds, from the ‘backside’, to the hinge region of its kinase domain, forming contacts with both amino-terminal and carboxy-terminal lobes. Structural analyses indicate that AID binding might constrain the mobility of helix αC, hence resulting in an autoinhibited KD-AID with much lower kinase activity than that of the kinase domain alone. AMP activates AMPK both allosterically and by inhibiting dephosphorylation. Further in vitro kinetic studies demonstrate that disruption of the KD-AID interface reverses the autoinhibition and these AMPK heterotrimeric mutants no longer respond to the change in AMP concentration. The structural and biochemical data have shown the primary mechanism of AMPK autoinhibition and suggest a conformational switch model for AMPK activation by AMP.

dUTP incorporation into genomic DNA is linked to transcription in yeast - Highly activated transcription is associated with eukaryotic genome instability, resulting in increased rates of mitotic recombination and mutagenesis. The association between high transcription and genome stability is probably due to a variety of factors including an enhanced accumulation of DNA damage, transcription-associated supercoiling, collision between replication forks and the transcription machinery, and the persistence of RNA–DNA hybrids. In the case of transcription-associated mutagenesis, we previously showed that there is a direct proportionality between the level of transcription and the mutation rate in the yeast Saccharomyces cerevisiae, and that the molecular nature of the mutations is affected by highly activated transcription. Here we show that the accumulation of apurinic/apyrimidinic sites is greatly enhanced in highly transcribed yeast DNA. We further demonstrate that most apurinic/apyrimidinic sites in highly transcribed DNA are derived from the removal of uracil, the presence of which is linked to direct incorporation of dUTP in place of dTTP. These results show an unexpected relationship between transcription and the fidelity of DNA synthesis, and raise intriguing cell biological issues with regard to nucleotide pool compartmentalization.

Self-assembly of DNA into nanoscale three-dimensional shapes - Nature459, 414–418 (2009)In this Letter, Figure 3 was printed incorrectly. The corrected figure is presented below.

The missing memristor found - Nature453, 80–83 (2008)In Fig. 2a of this Letter, the resistance for the right-hand element of the bottom circuit should be ROFF(1 - w/D), instead of the shown value ROFFw/D

Codename: Phoenix - Here comes the rain.