There’s something exciting and strange about having an idea. It can come suddenly. Unexpectedly. Randomly. Intensely. Ideas can uninvitingly appear full-forced and bright—like the cliché […]

The post Making the Smithsonian’s New “Sidedoor” podcast series a reality appeared first on Smithsonian Insider.

Living in deep reefs in the Atlantic Ocean, the banded basslet, a small and colorful species with a wide range of distribution, has long been […]

The post Fishy Caribbean ‘juveniles’ recognized as new species appeared first on Smithsonian Insider.

A one-cubic-foot approach to studying biodiversity as showcased in the new Biocube exhibit at the Smithsonian’s National Museum of Natural History has led to the […]

The post New parasitic crab species discovered during Smithsonian Biocube work in Solomon Islands appeared first on Smithsonian Insider.

The 11 farthest known stars in our galaxy are located about 300,000 light-years from Earth, well outside the Milky Way’s spiral disk. New research by […]

The post Farthest Milky Way stars might be ripped from another galaxy appeared first on Smithsonian Insider.

Recent underwater photographs and video from the National Marine Park of the southern Caribbean island of Bonaire has led to the discovery of a new species […]

The post Meet the candy striped hermit crab, a new Caribbean species appeared first on Smithsonian Insider.

Washington, D.C. is a city of symbols. The rites, rituals, and places that define Washington capture the aspirations of our nation and its citizens. Just […]

The post Trusted Sources: Why Museums and Libraries Are More Relevant Than Ever appeared first on Smithsonian Insider.

“Think of a lion shrunk to the size of a mouse that needs to eat every 20 minutes or so.” That is a shrew, says […]

The post New Costa Rican shrew species named from a single specimen found 44 years ago appeared first on Smithsonian Insider.

New species don’t just spring out of thin air. Speciation, the evolutionary process by which new and distinct species arise, usually takes millions of years. […]

The post Simultaneous hermaphrodites: Understanding Speciation in fish called “hamlets” appeared first on Smithsonian Insider.

A bizarre change occurs in the mouth of a humpback whale during its development in the womb. Several dozen tooth buds sprout in a row […]

The post Paleo-detectives energize great whale mystery: how & when baleen evolved appeared first on Smithsonian Insider.

Four years after conservationists relocated 570 desert tortoises (Gopherus agassizii) in California from a threatened habitat to a new nearby location, the tortoises outwardly appeared […]

The post Smithsonian Study shows relocated desert tortoises reproduce at lower rate appeared first on Smithsonian Insider.

Finding clean ways to store water is a challenge that humans have faced for millennia. In a new paper in Environmental Health, anthropologist Sabrina Sholts […]

The post Study shows ancient California Indians risked toxins from bitumen-coated bottles appeared first on Smithsonian Insider.

For more than 60 years, researchers have tried to successfully cryopreserve (or freeze) the embryo of zebrafish, a species that is an important medical model […]

The post Gold nanotechnology and lasers used to successfully freeze fish embryos appeared first on Smithsonian Insider.

In a new study in which one of humankind’s most high-tech tools was used to analyze one of its most primitive, scientists have uncovered evidence […]

The post Laser beams unveil secrets locked inside primitive stone spear points appeared first on Smithsonian Insider.

The next time you swat a fly ponder this: inside its belly is the DNA of whatever it ate before landing on your picnic dinner—roadkill, […]

The post Innovation: Belly gunk from flies used to survey forest animals appeared first on Smithsonian Insider.

In conflicts between predators and prey, speed is a decided advantage, and evolution has given the trap-jaw ant a distinct advantage with spring-loaded jaws that […]

The post Locked and loaded: unique trigger design fires this ant’s snapping jaws appeared first on Smithsonian Insider.

Hundreds of experiments have shown biodiversity fosters healthier, more productive ecosystems. But many experts doubted whether these experiments would hold up in the real world. […]

The post In the wild, biodiversity’s power surpasses what experiments predict appeared first on Smithsonian Insider.

Cats are notoriously fickle—purring in your lap one second, then swiping you with an indignant claw the next. One thing is certain however when it […]

The post Eons before viral kitten videos, ancient Egyptians adored cats appeared first on Smithsonian Insider.

Three former scientists from the Smithsonian’s National Zoological Park–Ellen Lamirande, Don Nichols, and Allan Pessier–were honored at the sixth annual Golden Goose Award ceremony at […]

The post Zoo scientists honored at Golden Goose appeared first on Smithsonian Insider.

This animation shows how binary neutron stars warp space-time to create gravitational waves, then collide and explode into a visible kilonova, which can be detected […]

The post Astronomers see light show associated with gravitational waves appeared first on Smithsonian Insider.

Today’s cutting-edge laboratories rely on ultra-cold refrigeration to keep delicate cells like sperm viable for use in the future. But a new technique using microwaves […]

The post What does candied, microwaved sperm have to do with saving endangered species? appeared first on Smithsonian Insider.

With a non-stop babble of hums, grunts and shrill squeals as they argue over fish and defend their territories, the Amazon’s giant otters are one […]

The post With voices joined in chorus, giant otter families create a distinct sound signature appeared first on Smithsonian Insider.

“Probably no genus of birds in the American avifauna has received the amount of attention that has been bestowed upon the turkeys…there has been no […]

The post Happy Thanksgiving! Here are 25 fun turkey-related objects in Smithsonian collections! appeared first on Smithsonian Insider.

A new study from the Smithsonian Conservation Biology Institute (SCBI) is helping make headway in an area of animal management that has historically proven challenging: […]

The post Early indicator of cheetah pregnancy identified appeared first on Smithsonian Insider.

One of Earth’s most evolutionarily unique species is also the world’s most trafficked mammal: pangolins, or “scaly anteaters.” A new study from the Smithsonian Conservation […]

The post Using genetics to help save world’s most trafficked mammal: the pangolin appeared first on Smithsonian Insider.

In 1854, a curious-looking spider was found preserved in 50 million-year-old amber. With an elongated neck-like structure and long mouthparts that protruded from the “head” […]

The post These newly discovered pelican spiders will make you want to visit Madagascar appeared first on Smithsonian Insider.

Flitting swiftly through the darkness above the tropical forest canopy in Central and South America, a group of cute little bats with dog-like faces have […]

The post More sky puppies! Scientists discover two new species of dog-faced bat appeared first on Smithsonian Insider.

Some of Hong Kong’s most disturbed and pristine marine environments were the recent focus of an intense 10-day MarineGEO survey of living organisms by a […]

The post MarineGEO survey conducted in Hong Kong appeared first on Smithsonian Insider.

Poaching wasn’t the largest conservation concern for Asian elephants, an endangered species, until satellite tracking stunned researchers. Scientists at the Smithsonian Conservation Biology Institute (SCBI) […]

The post Poachers are killing endangered Asian elephants for their skin and meat, not their tusks 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.

This winter has brought many intense and powerful storms, with cold fronts sweeping across much of the United States. On a much grander scale, astronomers […]

The post Scientists surprised by relentless cosmic cold front 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.

Very early on, cockroach moms found out maternal care gave their offspring a better chance at survival. The cockroach parenting method—which includes feeding, guarding and […]

The post Helicopter cockroach moms have protected their young for millions of years appeared first on Smithsonian Insider.

In the early 20th century, Canada geese were considered endangered in the U.S. So in the 1950s and 1960s, birds from the Midwest were released […]

The post Study of bacteria inside guts of wild Canada geese shows greater danger than earlier studies exposed appeared first on Smithsonian Insider.

Ninety Limosa harlequin frogs (Atelopus limosus) bred in human care are braving the elements of the wild after Smithsonian scientists sent them out into the […]

The post Panama: First release of endangered frogs appeared first on Smithsonian Insider.

Five new species of snail-eating snake, from a group of snakes affectionately known to scientists as “goo-eaters,” have been discovered by a team working in […]

The post Newly discovered snakes use curved teeth to pry snails from their shells appeared first on Smithsonian Insider.

Every queen deserves a castle, and the ruler of the Smithsonian’s National Zoo’s naked mole-rat colony is no different. After 27 years in a maze […]

The post Building a naked mole-rat dream home at the Smithsonian’s National Zoo 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 outer membrane of Gram-negative bacteria is highly impermeable to hydrophilic molecules of larger than 600 Da, protecting these bacteria from toxins present in the environment. In order to transport nutrients across this impermeable membrane, Gram-negative bacteria utilize a diverse family of outer-membrane proteins called TonB-dependent transporters. The majority of the members of this family transport iron-containing substrates. However, it is becoming increasingly clear that TonB-dependent transporters target chemically diverse substrates. In this work, the structure and phylogenetic distribution of the TonB-dependent transporter YncD are investigated. It is shown that while YncD is present in some enteropathogens, including Escherichia coli and Salmonella spp., it is also widespread in Gammaproteobacteria and Betaproteobacteria of environmental origin. The structure of YncD was determined, showing that despite a distant evolutionary relationship, it shares structural features with the ferric citrate transporter FecA, including a compact positively charged substrate-binding site. Despite these shared features, it is shown that YncD does not contribute to the growth of E. coli in pure culture under iron-limiting conditions or with ferric citrate as an iron source. Previous studies of transcriptional regulation in E. coli show that YncD is not induced under iron-limiting conditions and is unresponsive to the ferric uptake regulator (Fur). These observations, combined with the data presented here, suggest that YncD is not responsible for the transport of an iron-containing substrate.

Aldo-keto reductases (AKRs) are NADPH/NADP+-dependent oxidoreductase enzymes that metabolize an aldehyde/ketone to the corresponding alcohol. AKR4C14 from rice exhibits a much higher efficiency in metabolizing malondialdehyde (MDA) than do the Arabidopsis enzymes AKR4C8 and AKR4C9, despite sharing greater than 60% amino-acid sequence identity. This study confirms the role of rice AKR4C14 in the detoxification of methylglyoxal and MDA, and demonstrates that the endogenous contents of both aldehydes in transgenic Arabidopsis ectopically expressing AKR4C14 are significantly lower than their levels in the wild type. The apo structure of indica rice AKR4C14 was also determined in the absence of the cofactor, revealing the stabilized open conformation. This is the first crystal structure in AKR subfamily 4C from rice to be observed in the apo form (without bound NADP+). The refined AKR4C14 structure reveals a stabilized open conformation of loop B, suggesting the initial phase prior to cofactor binding. Based on the X-ray crystal structure, the substrate- and cofactor-binding pockets of AKR4C14 are formed by loops A, B, C and β1α1. Moreover, the residues Ser211 and Asn220 on loop B are proposed as the hinge residues that are responsible for conformational alteration while the cofactor binds. The open conformation of loop B is proposed to involve Phe216 pointing out from the cofactor-binding site and the opening of the safety belt. Structural comparison with other AKRs in subfamily 4C emphasizes the role of the substrate-channel wall, consisting of Trp24, Trp115, Tyr206, Phe216, Leu291 and Phe295, in substrate discrimination. In particular, Leu291 could contribute greatly to substrate selectivity, explaining the preference of AKR4C14 for its straight-chain aldehyde substrate.

Death-associated protein kinase 1 (DAPK1) is a serine/threonine protein kinase that regulates apoptosis and autophagy. DAPK1 is considered to be a therapeutic target for amyloid-β deposition, endometrial adenocarcinomas and acute ischemic stroke. Here, the potent inhibitory activity of the natural anthraquinone purpurin against DAPK1 phosphorylation is shown. Thermodynamic analysis revealed that while the binding affinity of purpurin is similar to that of CPR005231, which is a DAPK1 inhibitor with an imidazopyridazine moiety, the binding of purpurin was more enthalpically favorable. In addition, the inhibition potencies were correlated with the enthalpic changes but not with the binding affinities. Crystallographic analysis of the DAPK1–purpurin complex revealed that the formation of a hydrogen-bond network is likely to contribute to the favorable enthalpic changes and that stabilization of the glycine-rich loop may cause less favorable entropic changes. The present findings indicate that purpurin may be a good lead compound for the discovery of inhibitors of DAPK1, and the observation of enthalpic changes could provide important clues for drug development.

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.

The number of new X-ray crystallography-based submissions to the Protein Data Bank appears to be at the beginning of a decline, perhaps signalling an end to the era of the dominance of X-ray crystallography within structural biology. This letter, from the viewpoint of a young structural biologist, applies the Copernican method to the life expectancy of crystallography and asks whether the technique is still the mainstay of structural biology. A study of the rate of Protein Data Bank depositions allows a more nuanced analysis of the fortunes of macromolecular X-ray crystallography and shows that cryo-electron microscopy might now be outcompeting crystallography for new labour and talent, perhaps heralding a change in the landscape of the field.

Between the world wars of the early Twentieth Century, an age of adventure travel and cultural exploration flourished when newly developed transport and recording technologies–particularly […]

The post New Book: “Recreating First Contact: Expeditions, Anthropology, and Popular Culture” appeared first on Smithsonian Insider.

Imke K. Mandemaker, Di Zhou, Serena T. Bruens, Dick H. Dekkers, Pernette J. Verschure, Raghu R. Edupuganti, Eran Meshorer, Jeroen A. Demmers, and Jurgen A. Marteijn

Many chromatin remodeling and modifying proteins are involved in the DNA damage response by stimulating repair or inducing DNA damage signaling. Interestingly, here we identified that down regulation of the H1-interacting protein SET results in increased resistance to a wide variety of DNA damaging agents. We found that this increased resistance is not the result of an inhibitory effect of SET on DNA repair, but rather the consequence of a suppressed apoptotic response to DNA damage. We further provide evidence that the histone chaperone SET is responsible for the eviction of H1 from chromatin. Knock down of H1 in SET-depleted cells resulted in re-sensitization of cells to DNA damage, suggesting that the increased DNA damage resistance in SET-depleted cells is the result of enhanced retention of H1 on chromatin. Finally, clonogenic survival assays show that SET and p53 are epistatic in attenuating DNA damage-induced cell death. Altogether, our data show a role for SET in the DNA damage response as a regulator of cell survival following genotoxic stress.

Archan Chakraborty, Wei-Cheng Lin, Yu-Tsun Lin, Kuang-Jing Huang, Pei-Yu Wang, Yi-Feng Chang, Hsiang-Iu Wang, Kung-Ting Ma, Chun-Yen Wang, Xuan-Rong Huang, Yen-Hsien Lee, Bi-Chang Chen, Ya-Ju Hsieh, Kun-Yi Chien, Tzu-Yang Lin, Ji-Long Liu, Li-Ying Sung, Jau-Song Yu, Yu-Sun Chang, and Li-Mei Pai

Under metabolic stress, cellular components can assemble into distinct membraneless organelles for adaptation. One such example is cytidine 5'-triphosphate synthase (CTPS), which forms filamentous structures under glutamine deprivation. We have previously demonstrated that histidine (His)-mediated methylation regulates the formation of CTPS filaments to suppress enzymatic activity and preserve the CTPS protein under Gln deprivation, which promotes cancer cell growth after stress alleviation. However, it remains unclear where and how these enigmatic structures are assembled. Using CTPS-APEX2-mediated in vivo proximity labeling, we found that SNAP29 regulates the spatiotemporal filament assembly of CTPS along the cytokeratin network in a keratin 8 (KRT8)-dependent manner. Knockdown of synaptosome-associated protein 29 (SNAP29) interfered with assembly and relaxed the filament-induced suppression of CTPS enzymatic activity. Furthermore, APEX2 proximity labeling of keratin 18 (KRT18) revealed a spatiotemporal association of SNAP29 with cytokeratin in response to stress. Super-resolution imaging suggests that during CTPS filament formation, SNAP29 interacts with CTPS along the cytokeratin network. This study links the cytokeratin network to the regulation of metabolism by compartmentalization of metabolic enzymes during nutrient deprivation.

Laura O'Regan, Giancarlo Barone, Rozita Adib, Chang Gok Woo, Hui Jeong Jeong, Emily L. Richardson, Mark W. Richards, Patricia A.J. Muller, Spencer J. Collis, Dean A. Fennell, Jene Choi, Richard Bayliss, and Andrew M. Fry

EML4-ALK is an oncogenic fusion present in ~5% non-small cell lung cancers. However, alternative breakpoints in the EML4 gene lead to distinct variants with different patient outcomes. Here, we show in cell models that EML4-ALK variant 3 (V3), which is linked to accelerated metastatic spread, causes microtubule stabilization, formation of extended cytoplasmic protrusions and increased cell migration. It also recruits the NEK9 and NEK7 kinase to microtubules via the N-terminal EML4 microtubule-binding region. Overexpression of wild-type EML4 as well as constitutive activation of NEK9 also perturb cell morphology and accelerate migration in a microtubule-dependent manner that requires the downstream kinase NEK7 but not ALK activity. Strikingly, elevated NEK9 expression is associated with reduced progression-free survival in EML4-ALK patients. Hence, we propose that EML4-ALK V3 promotes microtubule stabilization through NEK9 and NEK7 leading to increased cell migration. This represents a novel actionable pathway that could drive metastatic disease progression in EML4-ALK lung cancer.