Τετάρτη 11 Μαρτίου 2020


Interferon lambda promotes immune dysregulation and tissue inflammation in TLR7-induced lupus [Immunology and Inflammation]
Type III IFN lambdas (IFN-λ) have recently been described as important mediators of immune responses at barrier surfaces. However, their role in autoimmune diseases such as systemic lupus erythematosus (SLE), a condition characterized by aberrant type I IFN signaling, has not been determined. Here, we identify a nonredundant role for...
Proceedings of the National Academy of Sciences current issue
14h
Reply to Desikan et al.: Micelle formation among various mechanisms of toxin pore formation [Biological Sciences]
Pore-forming toxins (PFTs) are a diverse class of membrane-active proteins employed primarily by bacteria for unregulated perforation of lipid membranes (1). Based on molecular dynamics (MD) simulations (2), electron cryo-microscopy (cryoEM) structures (3), and atomic force microscopy (AFM) experiments (4), we recently identified two distinct pathways for lipid efflux from...
Proceedings of the National Academy of Sciences current issue
14h
HIV-1 uncoats in the nucleus near sites of integration [Microbiology]
HIV-1 capsid core disassembly (uncoating) must occur before integration of viral genomic DNA into the host chromosomes, yet remarkably, the timing and cellular location of uncoating is unknown. Previous studies have proposed that intact viral cores are too large to fit through nuclear pores and uncoating occurs in the cytoplasm...
Proceedings of the National Academy of Sciences current issue
14h
MRI monitoring of energy storage in vivo using magnetization pathways [Medical Sciences]
Primary storage of energy in mammalian tissue is glycogen, a branched polysaccharide form of glucose. Glycogen serves a central role in glucose homeostasis and is crucial for proper system functioning. Altered glycogen metabolism is manifested in a variety of disorders such as diabetes, liver diseases, glycogen storage diseases, and cancer....
Proceedings of the National Academy of Sciences current issue
14h
Dynamics of life expectancy and life span equality [Social Sciences]
As people live longer, ages at death are becoming more similar. This dual advance over the last two centuries, a central aim of public health policies, is a major achievement of modern civilization. Some recent exceptions to the joint rise of life expectancy and life span equality, however, make it...
Proceedings of the National Academy of Sciences current issue
14h
PRR proteins of the circadian clock call time on shade avoidance [Plant Biology]
Light limitation represents a significant threat to plant survival. Shade-intolerant species have, therefore, evolved mechanisms to detect and avoid shading by neighbors. Plants detect the proximity and density of neighboring vegetation by monitoring alterations in light quality (1). Phytochrome photoreceptors detect changes in the ratio of red (R) to far-red...
Proceedings of the National Academy of Sciences current issue
14h
Nanoscale precipitates as sustainable dislocation sources for enhanced ductility and high strength [Engineering]
Traditionally, precipitates in a material are thought to serve as obstacles to dislocation glide and cause hardening of the material. This conventional wisdom, however, fails to explain recent discoveries of ultrahigh-strength and large-ductility materials with a high density of nanoscale precipitates, as obstacles to dislocation glide often lead to high...
Proceedings of the National Academy of Sciences current issue
14h
Dietary modification, penetrance, and the origins of congenital malformation [Medical Sciences]
Molecular genetic diagnostics refers to the branch of clinical medicine dedicated to finding the proximate mutational cause of an abnormality (1). More for practical than theoretical reasons, it generally assumes that a genetic variant is both necessary and sufficient to cause the defect, and hence that there is no need...
Proceedings of the National Academy of Sciences current issue
14h
A cnidarian parasite of salmon (Myxozoa: Henneguya) lacks a mitochondrial genome [Evolution]
Although aerobic respiration is a hallmark of eukaryotes, a few unicellular lineages, growing in hypoxic environments, have secondarily lost this ability. In the absence of oxygen, the mitochondria of these organisms have lost all or parts of their genomes and evolved into mitochondria-related organelles (MROs). There has been debate regarding...
Proceedings of the National Academy of Sciences current issue
14h
Moving beyond the West vs. the rest: Understanding variation within Asian groups and its societal consequences [Psychological and Cognitive Sciences]
After decades of focusing almost exclusively on Western populations, psychology and other social sciences have at last begun to diversify their samples. Massive efforts have been made to compare cultures around the globe on basic psychological processes, and researchers have amassed much evidence for differences between “the West and the...
Proceedings of the National Academy of Sciences current issue
14h
Massively parallel variant characterization identifies NUDT15 alleles associated with thiopurine toxicity [Genetics]
As a prototype of genomics-guided precision medicine, individualized thiopurine dosing based on pharmacogenetics is a highly effective way to mitigate hematopoietic toxicity of this class of drugs. Recently, NUDT15 deficiency was identified as a genetic cause of thiopurine toxicity, and NUDT15-informed preemptive dose reduction was quickly adopted in clinical settings....
Proceedings of the National Academy of Sciences current issue
14h
The size of the immune repertoire of bacteria [Biophysics and Computational Biology]
Some bacteria and archaea possess an immune system, based on the CRISPR-Cas mechanism, that confers adaptive immunity against viruses. In such species, individual prokaryotes maintain cassettes of viral DNA elements called spacers as a memory of past infections. Typically, the cassettes contain several dozen expressed spacers. Given that bacteria can...
Proceedings of the National Academy of Sciences current issue
14h
STAT3 signaling in myeloid cells promotes pathogenic myelin-specific T cell differentiation and autoimmune demyelination [Immunology and Inflammation]
Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the central nervous system. Dysregulation of STAT3, a transcription factor pivotal to various cellular processes including Th17 cell differentiation, has been implicated in MS. Here, we report that STAT3 is activated in infiltrating monocytic cells near active MS lesions and...
Proceedings of the National Academy of Sciences current issue
14h
Pathway-guided analysis identifies Myc-dependent alternative pre-mRNA splicing in aggressive prostate cancers [Applied Biological Sciences]
We sought to define the landscape of alternative pre-mRNA splicing in prostate cancers and the relationship of exon choice to known cancer driver alterations. To do so, we compiled a metadataset composed of 876 RNA-sequencing (RNA-Seq) samples from five publicly available sources representing a range of prostate phenotypes from normal...
Proceedings of the National Academy of Sciences current issue
14h
HNRNPA1-induced spliceopathy in a transgenic mouse model of myotonic dystrophy [Medical Sciences]
Studies on myotonic dystrophy type 1 (DM1) have led to the RNA-mediated disease model for hereditary disorders caused by noncoding microsatellite expansions. This model proposes that DM1 disease manifestations are caused by a reversion to fetal RNA processing patterns in adult tissues due to the expression of toxic CUG RNA...
Proceedings of the National Academy of Sciences current issue
14h
Bioinspired underwater locomotion of light-driven liquid crystal gels [Applied Physical Sciences]
Soft-bodied aquatic invertebrates, such as sea slugs and snails, are capable of diverse locomotion modes under water. Recapitulation of such multimodal aquatic locomotion in small-scale soft robots is challenging, due to difficulties in precise spatiotemporal control of deformations and inefficient underwater actuation of existing stimuli-responsive materials. Solving this challenge and...
Proceedings of the National Academy of Sciences current issue
14h
The habenular G-protein-coupled receptor 151 regulates synaptic plasticity and nicotine intake [Neuroscience]
The habenula, an ancient small brain area in the epithalamus, densely expresses nicotinic acetylcholine receptors and is critical for nicotine intake and aversion. As such, identification of strategies to manipulate habenular activity may yield approaches to treat nicotine addiction. Here we show that GPR151, an orphan G-protein–coupled receptor (GPCR) highly...
Proceedings of the National Academy of Sciences current issue
14h
Evaluation of a concerted vs. sequential oxygen activation mechanism in {alpha}-ketoglutarate-dependent nonheme ferrous enzymes [Biochemistry]
Determining the requirements for efficient oxygen (O2) activation is key to understanding how enzymes maintain efficacy and mitigate unproductive, often detrimental reactivity. For the α-ketoglutarate (αKG)–dependent nonheme iron enzymes, both a concerted mechanism (both cofactor and substrate binding prior to reaction with O2) and a sequential mechanism (cofactor binding and...
Proceedings of the National Academy of Sciences current issue
14h
Pinching a glass reveals key properties of its soft spots [Physics]
It is now well established that glasses feature quasilocalized nonphononic excitations—coined “soft spots”—, which follow a universal ω4 density of states in the limit of low frequencies ω. All glass-specific properties, such as the dependence on the preparation protocol or composition, are encapsulated in the nonuniversal prefactor of the universal...
Proceedings of the National Academy of Sciences current issue
14h
Mechanistic approaches for chemically modifying the coordination sphere of copper-amyloid-{beta} complexes [Biochemistry]
Neurotoxic implications of the interactions between Cu(I/II) and amyloid-β (Aβ) indicate a connection between amyloid cascade hypothesis and metal ion hypothesis with respect to the neurodegeneration associated with Alzheimer’s disease (AD). Herein, we report a mechanistic strategy for modifying the first coordination sphere of Cu(II) bound to Aβ utilizing a...
Proceedings of the National Academy of Sciences current issue
14h
Mining gold from implicit models to improve likelihood-free inference [Statistics]
Simulators often provide the best description of real-world phenomena. However, the probability density that they implicitly define is often intractable, leading to challenging inverse problems for inference. Recently, a number of techniques have been introduced in which a surrogate for the intractable density is learned, including normalizing flows and density...
Proceedings of the National Academy of Sciences current issue
14h
Trinuclear copper biocatalytic center forms an active site of thiocyanate dehydrogenase [Biochemistry]
Biocatalytic copper centers are generally involved in the activation and reduction of dioxygen, with only few exceptions known. Here we report the discovery and characterization of a previously undescribed copper center that forms the active site of a copper-containing enzyme thiocyanate dehydrogenase (suggested EC 1.8.2.7) that was purified from the...
Proceedings of the National Academy of Sciences current issue
14h
In This Issue [This Week in PNAS]
Animal lacking a mitochondrial genome Light microscope image of spores of H. salminicola from Chinook salmon. Aerobic respiration is a hallmark of eukaryotes but has been lost in several single-celled eukaryotic lineages adapted to low-oxygen environments. Whether certain animals also rely exclusively on anaerobic metabolism and have mitochondrion-related organelles (MROs)...
Proceedings of the National Academy of Sciences current issue
14h
Timing of fungal spore release dictates survival during atmospheric transport [Biophysics and Computational Biology]
Fungi disperse spores to move across landscapes and spore liberation takes different patterns. Many species release spores intermittently; others release spores at specific times of day. Despite intriguing evidence of periodicity, why (and if) the timing of spore release would matter to a fungus remains an open question. Here we...
Proceedings of the National Academy of Sciences current issue
14h
Capillary transfer of soft films [Engineering]
Existing transfer technologies in the construction of film-based electronics and devices are deeply established in the framework of native solid substrates. Here, we report a capillary approach that enables a fast, robust, and reliable transfer of soft films from liquid in a defect-free manner. This capillary transfer is underpinned by...
Proceedings of the National Academy of Sciences current issue
14h
Designing heterotropically activated allosteric conformational switches using supercharging [Biophysics and Computational Biology]
Heterotropic allosteric activation of protein function, in which binding of one ligand thermodynamically activates the binding of another, different ligand or substrate, is a fundamental control mechanism in metabolism and as such has been a long-aspired capability in protein design. Here we show that greatly increasing the magnitude of a...
Proceedings of the National Academy of Sciences current issue
14h
Oil and gas companies invest in legislators that vote against the environment [Environmental Sciences]
Do campaign contributions from oil and gas companies influence legislators to vote against the environment, or do these companies invest in legislators that have a proven antienvironmental voting record? Using 28 y of campaign contribution data, we find that evidence consistently supports the investment hypothesis: The more a given member...
Proceedings of the National Academy of Sciences current issue
14h
Exploring long-range cooperativity in the 20S proteasome core particle from Thermoplasma acidophilum using methyl-TROSY-based NMR [Biophysics and Computational Biology]
The 20S core particle (CP) proteasome is a molecular assembly catalyzing the degradation of misfolded proteins or proteins no longer required for function. It is composed of four stacked heptameric rings that form a barrel-like structure, sequestering proteolytic sites inside its lumen. Proteasome function is regulated by gates derived from...
Proceedings of the National Academy of Sciences current issue
14h
Dinoflagellates with relic endosymbiont nuclei as models for elucidating organellogenesis [Evolution]
Nucleomorphs are relic endosymbiont nuclei so far found only in two algal groups, cryptophytes and chlorarachniophytes, which have been studied to model the evolutionary process of integrating an endosymbiont alga into a host-governed plastid (organellogenesis). However, past studies suggest that DNA transfer from the endosymbiont to host nuclei had already...
Proceedings of the National Academy of Sciences current issue
14h
Short and simple sequences favored the emergence of N-helix phospho-ligand binding sites in the first enzymes [Biophysics and Computational Biology]
The ubiquity of phospho-ligands suggests that phosphate binding emerged at the earliest stage of protein evolution. To evaluate this hypothesis and unravel its details, we identified all phosphate-binding protein lineages in the Evolutionary Classification of Protein Domains database. We found at least 250 independent evolutionary lineages that bind small molecule...
Proceedings of the National Academy of Sciences current issue
14h
The ATAD2/ANCCA homolog Yta7 cooperates with Scm3HJURP to deposit Cse4CENP-A at the centromere in yeast [Genetics]
The AAA+ ATPase and bromodomain factor ATAD2/ANCCA is overexpressed in many types of cancer, but how it contributes to tumorigenesis is not understood. Here, we report that the Saccharomyces cerevisiae homolog Yta7ATAD2 is a deposition factor for the centromeric histone H3 variant Cse4CENP-A at the centromere in yeast. Yta7ATAD2 regulates...
Proceedings of the National Academy of Sciences current issue
14h
Global analysis of LARP1 translation targets reveals tunable and dynamic features of 5' TOP motifs [Cell Biology]
Terminal oligopyrimidine (TOP) motifs are sequences at the 5′ ends of mRNAs that link their translation to the mTOR Complex 1 (mTORC1) nutrient-sensing signaling pathway. They are commonly regarded as discrete elements that reside on ∼100 mRNAs that mostly encode translation factors. However, the full spectrum of TOP sequences and...
Proceedings of the National Academy of Sciences current issue
14h
Neuronal, stromal, and T-regulatory cell crosstalk in murine skeletal muscle [Immunology and Inflammation]
A distinct population of Foxp3+CD4+ regulatory T (Treg) cells promotes repair of acutely or chronically injured skeletal muscle. The accumulation of these cells depends critically on interleukin (IL)-33 produced by local mesenchymal stromal cells (mSCs). An intriguing physical association among muscle nerves, IL-33+ mSCs, and Tregs has been reported, and...
Proceedings of the National Academy of Sciences current issue
14h
Intrinsically disordered protein RBM14 plays a role in generation of RNA:DNA hybrids at double-strand break sites [Cell Biology]
Accumulating evidence suggests participation of RNA-binding proteins with intrinsically disordered domains (IDPs) in the DNA damage response (DDR). These IDPs form liquid compartments at DNA damage sites in a poly(ADP ribose) (PAR)-dependent manner. However, it is greatly unknown how the IDPs are involved in DDR. We have shown previously that...
Proceedings of the National Academy of Sciences current issue
14h
Chronic virus infection drives CD8 T cell-mediated thymic destruction and impaired negative selection [Immunology and Inflammation]
Chronic infection provokes alterations in inflammatory and suppressive pathways that potentially affect the function and integrity of multiple tissues, impacting both ongoing immune control and restorative immune therapies. Here we demonstrate that chronic lymphocytic choriomeningitis virus infection rapidly triggers severe thymic depletion, mediated by CD8 T cell-intrinsic type I interferon...
Proceedings of the National Academy of Sciences current issue
14h
Core Concept: Liquid metal renaissance points to wearables, soft robots, and new materials [Chemistry]
When chemical engineer Michael Dickey talks about his research on liquid metals, he knows what to expect. “People usually say mercury or the Terminator,” he says, alluding to the shape-shifting killer robot from the 1992 movie Terminator 2: Judgment Day. Even many researchers, he says, aren’t familiar with the unique...
Proceedings of the National Academy of Sciences current issue
14h
Joint profiling of chromatin accessibility and CAR-T integration site analysis at population and single-cell levels [Immunology and Inflammation]
Chimeric antigen receptor (CAR)-T immunotherapy has yielded impressive results in several B cell malignancies, establishing itself as a powerful means to redirect the natural properties of T lymphocytes. In this strategy, the T cell genome is modified by the integration of lentiviral vectors encoding CAR that direct tumor cell killing....
Proceedings of the National Academy of Sciences current issue
14h
Bottlebrush polymers in the melt and polyelectrolytes in solution share common structural features [Chemistry]
Uncharged bottlebrush polymer melts and highly charged polyelectrolytes in solution exhibit correlation peaks in scattering measurements and simulations. Given the striking superficial similarities of these scattering features, there may be a deeper structural interrelationship in these chemically different classes of materials. Correspondingly, we constructed a library of isotopically labeled bottlebrush...
Proceedings of the National Academy of Sciences current issue
14h
The fibroblast-derived protein PI16 controls neuropathic pain [Medical Sciences]
Chronic pain is a major clinical problem of which the mechanisms are incompletely understood. Here, we describe the concept that PI16, a protein of unknown function mainly produced by fibroblasts, controls neuropathic pain. The spared nerve injury (SNI) model of neuropathic pain increases PI16 protein levels in fibroblasts in dorsal...
Proceedings of the National Academy of Sciences current issue
14h

Δεν υπάρχουν σχόλια:

Δημοσίευση σχολίου

Αρχειοθήκη ιστολογίου