Some--birds called wire-tailed manakins, residents of tropical forests in the Americas--are cooperators as well as competitors. They cooperate, forming alliances for a common cause.

The post Manakins, birds of tropical forests, form alliances for common good appeared first on Smithsonian Insider.

Smithsonian scientists and collaborators have determined the evolutionary family tree for one of the most strikingly diverse and endangered bird families in the world, the Hawaiian honeycreepers.

The post Complete evolutionary tree of the Hawaiian honeycreepers traced by Smithsonian scientists, collaborators appeared first on Smithsonian Insider.

For the first time, astronomers have detected around a burgeoning solar system a sprawling cloud of water vapor that’s cold enough to form comets, which could eventually deliver oceans to dry planets.

The post Frigid water cloud may be source of water delivered to dry planets by comets appeared first on Smithsonian Insider.

To celebrate the 10th anniversary of researchers producing the first complete human genome sequence — the genetic blueprint of the human body — the Smithsonian’s National Museum of Natural History, will open a new high-tech, high-intensity exhibition in 2013.

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Their research revealed that the types of waterbirds that inhabit urban estuaries are influenced not only by urban development, but also by a far more natural process―rain.

The post Scientists find that rain may not always be a welcome thing to waterbirds appeared first on Smithsonian Insider.

Scientists at the University of Arizona and in California have completed the most challenging large astronomical mirror ever made.

The post First of seven mirrors completed for Giant Magellan Telescope appeared first on Smithsonian Insider.

Tiny as a mouse with a ‘prout brown’ body and three black stripes on its back Monodelphis gardneri from Peru bears little resemblance to its much larger cousin the North American opossum.

The post Tiny new Peruvian opossum comes from a great big family appeared first on Smithsonian Insider.

Using echolocation alone the bats found, identified and captured insects perched motionless and silent on the leaves of plants.

The post Common tropical bat uses echolocation with precision previously considered impossible, new experiments reveal appeared first on Smithsonian Insider.

Even dying stars could host planets with life – and if such life exists, we might be able to detect it within the next decade. […]

The post New evidence of extraterrestrial life may come from dying stars appeared first on Smithsonian Insider.

Spiral galaxies are some of the most beautiful and photogenic residents of the universe. Our own Milky Way is a spiral. Our solar system and […]

The post Powerful computer simulations show how spiral galaxies get their arms appeared first on Smithsonian Insider.

Hopes are high for Comet ISON, which has the potential to become the most spectacular comet seen in years. ISON is speeding through the inner […]

The post Micro-Observatory catches comet ISON appeared first on Smithsonian Insider.

Parents normally feel the need to provide well for their kids. For humans, that number of offspring is usually in the single digits, but a […]

The post The secret formula to feeding 900 babies: Scientists uncover milk composition of naked mole-rat queens appeared first on Smithsonian Insider.

On April 15 the National Museum of Natural History took delivery of a nearly complete Tyrannosaurus rex skeleton. Called the Nation’s T. rex, it will be the centerpiece of […]

The post Smithsonian Welcomes “Nation’s T. rex” to Washington, D.C. appeared first on Smithsonian Insider.

The Republic of Panama’s proposal to implement four Traffic Separation Schemes for commercial vessels entering and exiting the Panama Canal and ports was approved unanimously […]

The post Commercial shipping lanes changed in Panama to save humpback whales appeared first on Smithsonian Insider.

Tasty and easy to find, the heath hen was a favorite dish of America’s colonial settlers. This beautiful little bird, however, was no match for […]

The post Urban landscapes becoming increasingly bird-unfriendly appeared first on Smithsonian Insider.

A few images of comet 67P/Churyumov-Gerasimenko just sent back by the European spaceship Rosetta appear to be a snowboarder’s dream: pristine slopes covered in powder. […]

The post Comet probe set to answer ancient question of life on earth appeared first on Smithsonian Insider.

The challenges of conceiving only get greater as we get older. But if you have some of the most prized genes within your entire species, […]

The post High hopes for 60 year-old crocodile to become mother again appeared first on Smithsonian Insider.

Yabbies, mudbugs, crayfish, crawdads, call them what you will, but one-third of the world’s crayfish species are facing extinction according to a recent report by […]

The post Coming soon: Vacancy at the crawdad hole? appeared first on Smithsonian Insider.

For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disk surrounding a young […]

The post Complex Organic Molecules Discovered in Infant Star System appeared first on Smithsonian Insider.

The Smithsonian’s National Air and Space Museum has acquired a large collection from the Sir Arthur C. Clarke Trust. The collection consists of 87 cubic […]

The post Arthur C. Clarke papers come to Air and Space Museum Archives appeared first on Smithsonian Insider.

Tiny Anolis lizards preserved since the Miocene in amber are giving scientists a true appreciation of the meaning of community stability. Dating back some 15 […]

The post Trapped in Amber: Ancient fossils reveal remarkable stability of Caribbean lizard communities appeared first on Smithsonian Insider.

If you were dumped into the middle of a desert, your first instinct would be to look for water—it is, after all, the stuff of […]

The post In Western China’s deserts an ancient competition for water resumes appeared first on Smithsonian Insider.

Einstein’s general theory of relativity predicts the emission of gravitational waves by massive celestial bodies moving though space-time. For the past century gravitational waves have […]

The post Astronomers complete First Search for Visible Light Associated with Gravitational Waves appeared first on Smithsonian Insider.

Higher acidity in coastal waters can make fish more sensitive to low oxygen, causing them to become debilitated and suffocate in water with oxygen levels […]

The post Acidification, Low Oxygen Can be Deadly Combination for Fish appeared first on Smithsonian Insider.

The National Zoo’s red panda habitat on Asia Trail reopened to the public Tuesday, May 10. Tusa and Asa explored their new home which has […]

The post Red pandas come back to Zoo appeared first on Smithsonian Insider.

One of the primary features that distinguish hominids such as chimpanzees, gorillas and humans from the rest of the animal kingdom are uniquely dexterous hands. […]

The post Did ripening fruit help hominids develop complex hands? appeared first on Smithsonian Insider.

In a recently completed survey of more than 3,000 fish species in 44 countries around the world marine biologists have discovered that communities with a […]

The post Discovery: Biodiversity shields fish communities from warming appeared first on Smithsonian Insider.

Astronomers announced today that they have found the organic molecule methyl alcohol, or methanol, in the TW Hydrae protoplanetary disk. This is the first such […]

The post Methanol reveals comets forming in distant solar system appeared first on Smithsonian Insider.

In 2012, under a scientist’s watchful eye, a comb jelly ate some fish, digested it, and excreted the waste out its back end. In doing […]

The post By simply pooping, comb jellies expel long-held scientific misconception appeared first on Smithsonian Insider.

The blue whale, which uses baleen to filter its prey from ocean water and can reach lengths of over 100 feet, is the largest vertebrate […]

The post Only recently did whales become giant appeared first on Smithsonian Insider.

Chances are, if you’ve been stung by a jellyfish along the Chesapeake Bay it was by a sea nettle jellyfish–one of the most common and […]

The post Scientists discover common sea nettle jellyfish is actually two distinct species appeared first on Smithsonian Insider.

There are currently more than 3,500 confirmed known exoplanets thanks to the remarkable sensitivity of the Kepler spacecraft and to technological advances in space and […]

The post Astronomers detect comets transiting distant stars appeared first on Smithsonian Insider.

Every day, astronomers at the Harvard-Smithsonian Center for Astrophysics depend on computers to help them solve the mysteries of the universe, just as they did […]

The post Underpaid women “computers” mapped the universe in the 19th century appeared first on Smithsonian Insider.

Animal species can become endangered, but what about languages? Around 80 percent of the world’s population speaks just 20 percent of its 7,000 languages. That […]

The post Why languages become endangered, and how we can keep them alive appeared first on Smithsonian Insider.

When many people think of the Chesapeake Bay, one of the first creatures that comes to mind is the iconic blue crab. But parts of […]

The post Smithsonian scientists become shark detectives to track species in the Chesapeake Bay appeared first on Smithsonian Insider.

l-Hydroxyproline (l-Hyp) is a nonstandard amino acid that is present in certain proteins, in some antibiotics and in the cell-wall components of plants. l-Hyp is the product of the post-translational modification of protein prolines by prolyl hydroxylase enzymes, and the isomers trans-3-hydroxy-l-proline (T3LHyp) and trans-4-hydroxy-l-proline (T4LHyp) are major components of mammalian collagen. T4LHyp follows two distinct degradation pathways in bacteria and mammals, while T3LHyp is metabolized by a two-step metabolic pathway that is conserved in bacteria and mammals, which involves a T3LHyp dehydratase and a Δ1-pyrroline-2-carboxylate (Pyr2C) reductase. In order to shed light on the structure and catalysis of the enzyme involved in the second step of the T3LHyp degradation pathway, the crystal structure of Pyr2C reductase from the archaeon Thermococcus litoralis DSM 5473 complexed with NADH and l-proline is presented. The model allows the mapping of the residues involved in cofactor and product binding and represents a valid model for rationalizing the catalysis of Pyr2C reductases.

The biological processes related to protein homeostasis in Mycobacterium tuberculosis, the etiologic agent of tuberculosis, have recently been established as critical pathways for therapeutic intervention. Proteins of particular interest are ClpC1 and the ClpC1–ClpP1–ClpP2 proteasome complex. The structure of the potent antituberculosis macrocyclic depsipeptide ecumicin complexed with the N-terminal domain of ClpC1 (ClpC1-NTD) is presented here. Crystals of the ClpC1-NTD–ecumicin complex were monoclinic (unit-cell parameters a = 80.0, b = 130.0, c = 112.0 Å, β = 90.07°; space group P21; 12 complexes per asymmetric unit) and diffracted to 2.5 Å resolution. The structure was solved by molecular replacement using the self-rotation function to resolve space-group ambiguities. The new structure of the ecumicin complex showed a unique 1:2 (target:ligand) stoichiometry exploiting the intramolecular dyad in the α-helical fold of the target N-terminal domain. The structure of the ecumicin complex unveiled extensive interactions in the uniquely extended N-terminus, a critical binding site for the known cyclopeptide complexes. This structure, in comparison with the previously reported rufomycin I complex, revealed unique features that could be relevant for understanding the mechanism of action of these potential antituberculosis drug leads. Comparison of the ecumicin complex and the ClpC1-NTD-L92S/L96P double-mutant structure with the available structures of rufomycin I and cyclomarin A complexes revealed a range of conformational changes available to this small N-terminal helical domain and the minor helical alterations involved in the antibiotic-resistance mechanism. The different modes of binding and structural alterations could be related to distinct modes of action.

Leucocyte common antigen-related protein (LAR) is a post-synaptic type I transmembrane receptor protein that is important for neuronal functionality and is genetically coupled to neuronal disorders such as attention deficit hyperactivity disorder (ADHD). To understand the molecular function of LAR, structural and biochemical studies of protein fragments derived from the ectodomain of human LAR have been performed. The crystal structure of a fragment encompassing the first four FNIII domains (LARFN1–4) showed a characteristic L shape. SAXS data suggested limited flexibility within LARFN1–4, while rigid-body refinement of the SAXS data using the X-ray-derived atomic model showed a smaller angle between the domains defining the L shape compared with the crystal structure. The capabilities of the individual LAR fragments to interact with heparin was examined using microscale thermophoresis and heparin-affinity chromatography. The results showed that the three N-terminal immunoglobulin domains (LARIg1–3) and the four C-terminal FNIII domains (LARFN5–8) both bound heparin, while LARFN1–4 did not. The low-molecular-weight heparin drug Innohep induced a shift in hydrodynamic volume as assessed by size-exclusion chromatography of LARIg1–3 and LARFN5–8, while the chemically defined pentameric heparin drug Arixtra did not. Together, the presented results suggest the presence of an additional heparin-binding site in human LAR.

Hem Sapkota, Jonathan D. Wren, and Gary J. Gorbsky

Centrosomes focus microtubules to promote mitotic spindle bipolarity, a critical requirement for balanced chromosome segregation. Comprehensive understanding of centrosome function and regulation requires a complete inventory of components. While many centrosome components have been identified, others may yet remain undiscovered. We have used a bioinformatics approach, based on "guilt by association" expression to identify novel mitotic components among the large group of predicted human proteins that have yet to be functionally characterized. Here we identify Chondrosarcoma-Associated Gene 1 (CSAG1) in maintaining centrosome integrity during mitosis. Depletion of CSAG1 disrupts centrosomes and leads to multipolar spindles more effectively in cells with compromised p53 function. Thus, CSAG1 may reflect a class of "mitotic addiction" genes whose expression is more essential in transformed cells.

Karolina Losenkova, Mariachiara Zuccarini, Marika Karikoski, Juha Laurila, Detlev Boison, Sirpa Jalkanen, and Gennady G. Yegutkin

Extracellular adenosine mediates diverse anti-inflammatory, angiogenic and vasoactive effects and becomes an important therapeutic target for cancer, which has been translated into clinical trials. This study was designed to comprehensively assess adenosine metabolism in prostate and breast cancer cells. We identified cellular adenosine turnover as a complex cascade, comprised of (a) the ectoenzymatic breakdown of ATP via sequential nucleotide pyrophosphatase/phosphodiesterase-1, ecto-5’-nucleotidase/CD73 and adenosine deaminase reactions, and ATP re-synthesis through counteracting adenylate kinase and nucleoside diphosphokinase; (b) the uptake of nucleotide-derived adenosine via equilibrative nucleoside transporters; and (c) the intracellular adenosine phosphorylation into ATP by adenosine kinase and other nucleotide kinases. The exposure of cancer cells to 1% O₂ for 24 hours triggered ~2-fold up-regulation of CD73, without affecting nucleoside transporters, adenosine kinase activity and cellular ATP content. The ability of adenosine to inhibit the tumor-initiating potential of breast cancer cells via receptor-independent mechanism was confirmed in vivo using a xenograft mouse model. The existence of redundant pathways controlling extracellular and intracellular adenosine provides a sufficient justification for reexamination of the current concepts of cellular purine homeostasis and signaling in cancer.

Laurence Haren, Dorian Farache, Laurent Emorine, and Andreas Merdes

-tubulin is a major protein involved in the nucleation of microtubules in all eukaryotes. It forms two different complexes with proteins of the GCP family (gamma-tubulin complex proteins): -tubulin small complexes (TuSCs), containing -tubulin and GCPs 2 and 3, and -tubulin ring complexes (TuRCs), containing multiple TuSCs, in addition to GCPs 4, 5, and 6. Whereas the structure and assembly properties of TuSCs have been intensively studied, little is known about the assembly of TuRCs, and about the specific roles of GCPs 4, 5, and 6. Here, we demonstrate that two copies of GCP4 and one copy each of GCP5 and GCP6 form a salt-resistant sub-complex within the TuRC that assembles independently of the presence of TuSCs. Incubation of this sub-complex with cytoplasmic extracts containing TuSCs leads to the reconstitution of TuRCs that are competent to nucleate microtubules. In addition, we investigate sequence extensions and insertions that are specifically found at the amino-terminus of GCP6, and between the GCP6 grip1 and grip2 motifs, and we demonstrate that these are involved in the assembly or stabilization of the TuRC.

Westley Heydeck, Brian A. Bayless, Alexander J. Stemm-Wolf, Eileen T. O'Toole, Amy S. Fabritius, Courtney Ozzello, Marina Nguyen, and Mark Winey

Basal bodies (BBs) are microtubule-based organelles that template and stabilize cilia at the cell surface. Centrins ubiquitously associate with BBs and function in BB assembly, maturation, and stability. Human POC5 (hPOC5) is a highly conserved centrin-binding protein that binds centrins through Sfi1p-like repeats and is required for building full-length, mature centrioles. Here, we use the BB-rich cytoskeleton of Tetrahymena thermophila to characterize Poc5 BB functions. Tetrahymena Poc5 (TtPoc5) uniquely incorporates into assembling BBs and is then removed from mature BBs prior to ciliogenesis. Complete genomic knockout of TtPOC5 leads to a significantly increased production of BBs yet a markedly reduced ciliary density, both of which are rescued by reintroduction of TtPoc5. A second Tetrahymena POC5-like gene, SFR1, is similarly implicated in modulating BB production. When TtPOC5 and SFR1 are co-deleted, cell viability is compromised, and levels of BB overproduction are exacerbated. Overproduced BBs display defective transition zone formation and a diminished capacity for ciliogenesis. This study uncovers a requirement for Poc5 in building mature BBs, providing a possible functional link between hPOC5 mutations and impaired cilia.

Thomas O'Loughlin, Antonina J. Kruppa, Andre L. R. Ribeiro, James R. Edgar, Abdulaziz Ghannam, Andrew M. Smith, and Folma Buss

Optineurin (OPTN) is a multifunctional protein involved in autophagy, secretion as well as NF-B and IRF3 signalling and OPTN mutations are associated with several human diseases. Here we show that, in response to viral RNA, OPTN translocates to foci in the perinuclear region, where it negatively regulates NF-B and IRF3 signalling pathways and downstream pro-inflammatory cytokine secretion. These OPTN foci consist of a tight cluster of small membrane vesicles, which are positive for ATG9A. Disease mutations linked to POAG cause aberrant foci formation in the absence of stimuli, which correlates with the ability of OPTN to inhibit signalling. Using proximity labelling proteomics, we identify the LUBAC complex, CYLD and TBK1 as part of the OPTN interactome and show that these proteins are recruited to this OPTN-positive perinuclear compartment. Our work uncovers a crucial role for OPTN in dampening NF-B and IRF3 signalling through the sequestration of LUBAC and other positive regulators in this viral RNA-induced compartment leading to altered pro-inflammatory cytokine secretion.

Smithsonian Institution Libraries has recently acquired a rare first edition of Darwin's Geological Observations on the Volcanic Islands, Visited During the Voyage of the H.M.S. Beagle.

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A 3-D rendering of the Apollo 11 Command Module with a view inside the hatch. The seats inside are where astronauts Neil Armstrong, Buzz Aldrin […]

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In the battle against invasive species, giant commercial ships are on the front lines. But even when they follow the rules, one of their best […]

The post Battle against invasive marine species comes up short as global shipping surges appeared first on Smithsonian Insider.

When Smithsonian Conservation Biology Institute conservation biologist Jessica Deichmann joined a project to determine how the construction of a road in Gabon’s Moukalaba-Doudou National Park […]

The post DNA untangles Gabon’s complex web of frog species appeared first on Smithsonian Insider.