In 1969, 60 to 100 peacock bass imported from Buga, Colombia, were introduced into a pond in Panama for sport fishing. Several individuals escaped. By […]

The post Peacock bass invasion Had devastating, long-term impact on Panama’s Fish 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.

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.

Using new numerical simulations and observations, scientists may now be able to explain why the Sun’s magnetic field reverses every eleven years. This significant discovery […]

The post 3D simulations reveals why the Sun flips its magnetic field every 11 years appeared first on Smithsonian Insider.

Covered in sharp spines, when harassed the porcupine fish inflates like a balloon. Think of a small soccer ball bristling all over with nails. Most predators […]

The post Indestructible jaws from ancient, extinct porcupine fish reveal new species appeared first on Smithsonian Insider.

When fast radio bursts, or FRBs, were first detected in 2001, astronomers had never seen anything like them before. Since then, astronomers have found a […]

The post New study indicates mysterious fast radio bursts occur in universe every second appeared first on Smithsonian Insider.

Plastic debris floating in the ocean has become a powerful new passport to far-away destinations for a wide variety of invasive species, according to new […]

The post Tsunami reveals drifting ocean plastic opens globe to invasive castaways appeared first on Smithsonian Insider.

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.

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.

Tidal Freshwater Wetlands focuses on wetlands found in North America and Europe near the mouths of rivers that flow into estuaries like the Chesapeake Bay.

The post New book reveals tidal freshwater wetlands are on frontlines of global change appeared first on Smithsonian Insider.

Some of the earliest humans to inhabit America came from Europe according to a new book "Across Atlantic Ice: The Origin of America's Clovis Culture."

The post New book reveals Ice Age mariners from Europe were America’s first inhabitants appeared first on Smithsonian Insider.

Photographs, by virtue of their static nature, not only allow us to look back to a fixed point in time, but also give us a […]

The post Book Review: Double Exposure: photos of African American History & 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.

Liza Botros MD., Manon C. A. Pronk PhD., Jenny Juschten MD., John Liddle, Sofia K. S. H. Morsing, Jaap D. van Buul PhD., Robert H. Bates, Pieter R. Tuinman MD. PhD., Jan S. M. van Bezu, Stephan Huveneers PhD., Harm Jan Bogaard MD. PhD., Victor W. M. van Hinsbergh PhD., Peter L. Hordijk PhD., and Jurjan Aman MD. PhD.

Aims: Endothelial barrier dysfunction leads to edema and vascular leak, carrying high morbidity and mortality. Previously, Abl kinase inhibition was shown to protect against vascular leak. Using the distinct inhibitory profiles of clinically available Abl kinase inhibitors, we aimed to provide a mechanistic basis for novel treatment strategies against vascular leakage syndromes.

Methods & Results: Bosutinib most potently protected against inflammation-induced endothelial barrier disruption. In vivo, bosutinib prevented LPS-induced alveolar protein extravasation in an acute lung injury mice model. Mechanistically, Mitogen-activated Protein 4 Kinase 4 (MAP4K4) was identified as important novel mediator of endothelial permeability, which signals via ezrin, radixin and moesin proteins to increase turnover of integrin-based focal adhesions. The combined inhibition of MAP4K4 and Arg by bosutinib preserved adherens junction integrity and reduced turnover of focal adhesions, which synergistically act to stabilize the endothelial barrier during inflammation.

Conclusion: MAP4K4 was identified as important regulator of endothelial barrier integrity, increasing focal adhesion turnover and disruption of cell-cell junctions during inflammation. Inhibiting both Arg and MAP4K4, the clinically available drug bosutinib may form a viable strategy against vascular leakage syndromes.

Björn Eismann, Teresa G. Krieger, Jürgen Beneke, Ruben Bulkescher, Lukas Adam, Holger Erfle, Carl Herrmann, Roland Eils, and Christian Conrad

3D cell cultures enable the in vitro study of dynamic biological processes such as the cell cycle, but their use in high-throughput screens remains impractical with conventional fluorescent microscopy. Here, we present a screening workflow for the automated evaluation of mitotic phenotypes in 3D cell cultures by light-sheet microscopy. After sample preparation by a liquid handling robot, cell spheroids are imaged for 24 hours in toto with a dual-view inverted selective plane illumination microscope (diSPIM) with a much improved signal-to-noise ratio, higher imaging speed, isotropic resolution and reduced light exposure compared to a spinning disc confocal microscope. A dedicated high-content image processing pipeline implements convolutional neural network based phenotype classification. We illustrate the potential of our approach by siRNA knock-down and epigenetic modification of 28 mitotic target genes for assessing their phenotypic role in mitosis. By rendering light-sheet microscopy operational for high-throughput screening applications, this workflow enables target gene characterization or drug candidate evaluation in tissue-like 3D cell culture models.

Su Ming Sun, Amandine Batte, Mireille Tittel-Elmer, Sophie van der Horst, Tibor van Welsem, Gordon Bean, Trey Ideker, Fred van Leeuwen, and Haico van Attikum

Eukaryotic chromosomes are replicated in interphase and the two newly duplicated sister chromatids are held together by the cohesin complex and several cohesin auxiliary factors. Sister chromatid cohesion is essential for accurate chromosome segregation during mitosis, yet has also been implicated in other processes, including DNA damage repair, transcription and DNA replication. To assess how cohesin and associated factors functionally interconnect and coordinate with other cellular processes, we systematically mapped genetic interactions of 17 cohesin genes centered on quantitative growth measurements of >52,000 gene pairs in budding yeast. Integration of synthetic genetic interactions unveiled a cohesin functional map that constitutes 373 genetic interactions, revealing novel functional connections with post-replication repair, microtubule organization and protein folding. Accordingly, we show that the microtubule-associated protein Irc15 and the prefoldin complex members Gim3, Gim4 and Yke2 are new factors involved in sister chromatid cohesion. Our genetic interaction map thus provides a unique resource for further identification and functional interrogation of cohesin proteins. Since mutations in cohesin proteins have been associated with cohesinopathies and cancer, it may also identify cohesin interactions relevant in disease etiology.

M. Pinar and M. A. Penalva

TRAnsport Protein Particle (TRAPP) complexes regulate membrane traffic. TRAPPII and TRAPPIII share a core hetero-heptamer, also denoted TRAPPI. In fungi TRAPPIII and TRAPPII mediate GDP exchange on RAB1 and RAB11, respectively, regulating traffic across the Golgi, with TRAPPIII also activating RAB1 in autophagosomes. Our finding that Aspergillus nidulans TRAPPII can be assembled by addition of a TRAPPII-specific subcomplex onto core TRAPP prompted us to investigate the possibility that TRAPPI/TRAPPIII already residing in the Golgi matures into TRAPPII to determine a RAB1-to-RAB11 conversion as Golgi cisternae progress from early Golgi to TGN identity. By time-resolved microscopy we determine that the TRAPPII reporter Trs120/TRAPPC9 is recruited to existing TGN cisternae slightly before RAB11 arrives, and resides for~45 sec on them before cisternae tear off into RAB11 secretory carriers. Notably, the core TRAPP reporter Bet3/TRAPPC3 was not detectable in early Golgi cisternae, being instead recruited to TGN cisternae simultaneously with Trs120/TRAPPC9, indicating en bloc recruitment of TRAPPII to the Golgi and arguing strongly against the TRAPP maturation model.

The geologic faults responsible for the rise of the eastern Andes mountains in Colombia became active 25 million years ago—18 million years before the previously accepted start date for the Andes’ rise.

The post Andes Mountains Are Older Than Previously Believed appeared first on Smithsonian Insider.

The number and diversity of tectonic landforms in our solar system “is truly remarkable,” Watters and Schultz write. Photographs of these structures have stimulated a range of scholarly investigations.

The post Book Review: Planetary Tectonics examines otherworldly landforms appeared first on Smithsonian Insider.

A mysterious cycle of booms and busts in marine biodiversity over the past 500 million years could be tied to a periodic uplifting of the world's continents, scientists report

The post Boom and bust cycle of marine biodiversity every 60 million years linked to uplifting of continents appeared first on Smithsonian Insider.

New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface.

The post Photos reveal recent activity in moon’s crust appeared first on Smithsonian Insider.

The humble salamander may provide evidence to support a controversial claim that North and South America were joined together much earlier than previously thought. The […]

The post Salamander DNA reveals evidence of older land connection between Central and South America appeared first on Smithsonian Insider.

Miniature camels and horses, a rhinoceros and a giant bear-dog are among fossils unearthed in the recent excavations of the Panama Canal expansion project. These […]

The post First five years of Panama Canal excavations reveal fossil finds appeared first on Smithsonian Insider.

Even tiny crustaceans scuttling across the deepest, darkest depths of the ocean floor will feel the effects of climate change, according to a new study […]

The post Climate change to impact even deep-ocean ecosystems appeared first on Smithsonian Insider.

Many traits unique to humans were long thought to have originated in the genus Homo between 2.4 and 1.8 million years ago in Africa. A […]

The post Human Evolution Rewritten: We owe our existence to our ancestor’s flexible response to climate change appeared first on Smithsonian Insider.

George Smith, a marine biologist at the Smithsonian Environmental Research Center, explains his work of finding ways to prevent invasive species from being released in Baltimore Harbor in the ballast water of large ships.

The post Preventing ballast-water invasions of alien species appeared first on Smithsonian Insider.

Here come the stinkbugs...With the cooler temperatures of fall the brown marmorated stinkbug begins a determined quest to find a warm place to spend the winter. Crowding around window screens and searching for other ways to get inside, homeowners in the United States will share their indoor living space this winter with millions of brown marmorated stinkbugs. In this video Gary Hevel, an entomolgist at the Smithsonian's National Museum of Natural History, shares some information about these interesting creatures, as well as some advice about how to deal with those that inevitably gain entry to your home.

The post Smithsonian entomologist Gary Hevel gives information and advice about stinkbugs in your home appeared first on Smithsonian Insider.

What does it take to care for a pride of lions? Go behind the scenes with Great Cats Curator Craig Saffoe as he works with animal keepers and veterinarians to prepare the National Zoo's frisky lion cubs for their public debut. For more about the Zoo's growing pride and to watch them on live webcams: http://nationalzoo.si.edu/Animals/GreatCats/default.cfm?cam=LC4

The post Great Cats curator Craig Saffoe discusses his work caring for the National Zoo’s seven frisky lion cubs appeared first on Smithsonian Insider.

The post Device at the Smithsonian Environmental Research Center examines how phytoplankton would react if the ozone layer vanished appeared first on Smithsonian Insider.

School's nearly back in session, but the seven young lions at the Smithsonian's National Zoo have been working hard through the summer months!

The post Lion cub summer school: Instead of learning their ABCs, the National Zoo’s lion cubs are learning behaviors that will help animal care staff evaluate their health. appeared first on Smithsonian Insider.

Meet Rachel Collin, a staff scientist and director of the Bocas Research Station at the Smithsonian Tropical Research Institute in Panama. Rachel studies the evolution of marine gastropods (snails) and oversees multiple disciplines of marine biology at the Collin Lab in Bocas del Toro.

The post Meet Our Scientist: Rachel Collin, an expert in the evolution and development of snails who is working in Panama appeared first on Smithsonian Insider.

The post How do we know if dinosaurs cared for their young? Smithsonian curator Matthew Carrano reveals the fossil evidence. appeared first on Smithsonian Insider.

The post Samuel P. Langley, Secretary of the Smithsonian, and his development of the ill-fated Aerodrome A appeared first on Smithsonian Insider.

Jennifer Trask engages nature as both medium and subject matter, combining unexpected materials such as bone, vertebrae, butterfly wings, resin, metal, and antique frame fragments […]

The post Jennifer Trask – Visions and Revisions: Renwick Invitational 2016 appeared first on Smithsonian Insider.

Steven Young Lee blends Eastern and Western traditions with anachronistic, often playful imagery and striking pattern in his porcelain works. His process allows the clay […]

The post Steven Young Lee-Visions and Revisions: Renwick Invitational 2016 appeared first on Smithsonian Insider.

At age 19, athlete Amy Purdy had both legs amputated below the knee due to a sudden illness that culminated in septic shock. Two years […]

The post With Grit and Innovation “Everyone Plays” appeared first on Smithsonian Insider.

The post Reagan and Gorbachev’s Relationship Warmed Cold War Tensions appeared first on Smithsonian Insider.

The Smithsonian’s National Museum of African Art is the first institution to acquire the deeply personal and visually mesmerizing video projections “Invocation: The Severance of […]

The post Chuchu: The Severance of Ties and Invocation appeared first on Smithsonian Insider.

Highlights of the year 2017 Freer Gallery of Art and Arthur M. Sackler Gallery

The post 2017 Freer|Sackler Year in Review appeared first on Smithsonian Insider.

 Inspired by Steampunk design, Richard Wilks talks about his larger than life 3-point mobile contraption. Through the merging of transportation and art, he created […]

The post Artist Richard Wilkes on “Evotrope” appeared first on Smithsonian Insider.

This animation tells a Cheyenne story of how the Big Dipper came to be when a girl and her loyal brothers escape from a bison. […]

The post Quillwork Girl and Her New Seven Brothers appeared first on Smithsonian Insider.

Latinus 9333 is the Latin translation of the so-called Tacuinum sanitatis, a medieval handbook on wellness written in Arabic by the 11th-century physician ibn Butlan. It deals with factors influencing human health: from the air, the environment and food, to physical exercise and sexual activity.

The post Medieval book is important resource for how plants were once collected, treated and used appeared first on Smithsonian Insider.

Botanists Gerhard Zotz of the Smithsonian Tropical Research Institute and Stefan Wester of the University of Oldenburg in Germany decided to take a closer look at these high-wire bromeliads. They were interested to find out how the growth and survival rates of these plants on electrical cables compared to the growth and survival of plants of the same species growing in trees--their natural environment.

The post Study reveals hazards of the high-wire life for bromeliads appeared first on Smithsonian Insider.

Recent analysis using DNA sequencing of ancient Roman pills found aboard a ship that sank in Italy’s Gulf of Baratti between 140 -120 B.C, has revealed that the medicines consist of material from simple garden plants, namely carrot, radish, parsley, celery, wild onion and cabbage.

The post DNA sequencing reveals simple vegetables in ancient Roman medicines appeared first on Smithsonian Insider.

A 48 million-year-old fossilized leaf has revealed the oldest known evidence of a macabre part of nature – parasites taking control of their hosts to turn them into zombies.

The post Fossil reveals 48-million year history of zombie ants appeared first on Smithsonian Insider.

Nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.

The post Plant diversity in tropical forests increased during ancient global warming event appeared first on Smithsonian Insider.

Despite many laws to protect it, a new survey reveals wild ginseng in Maryland is on the decline.

The post Wild ginseng in steep decline in Maryland, survey reveals: Q&A with Smithsonian botanist Christopher Puttock appeared first on Smithsonian Insider.

Going for the gut will soon become standard protocol for scientists working to unravel the complex living web of interactions between plants and animals on […]

The post Going for the gut: DNA from beetle stomachs reveals complex network appeared first on Smithsonian Insider.

One way to avoid a cold or the flu, doctors say, is to stay away from crowded places. Viruses spread fast in places where people […]

The post Sugar is key ingredient to evolutionary success of ants, researchers find appeared first on Smithsonian Insider.

For centuries untold numbers of this tiny arachnid (cousin to spiders and ticks) have ended up in teapots, invisibly steeping alongside the leaves of the tea plant on which it lives.

The post Primitive, bizarre, beautiful: New mite species reveal a lost world awaiting discovery appeared first on Smithsonian Insider.