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Τρίτη 24 Σεπτεμβρίου 2019


Chemical and structural analysis of a photoactive vertebrate cryptochrome from pigeon [Biochemistry]
Computational and biochemical studies implicate the blue-light sensor cryptochrome (CRY) as an endogenous light-dependent magnetosensor enabling migratory birds to navigate using the Earth’s magnetic field. Validation of such a mechanism has been hampered by the absence of structures of vertebrate CRYs that have functional photochemistry. Here we present crystal structures...
Proceedings of the National Academy of Sciences Biochemistry
12h
Energetics of the exchangeable quinone, QB, in Photosystem II [Biochemistry]
Photosystem II (PSII), the light-driven water/plastoquinone photooxidoreductase, is of central importance in the planetary energy cycle. The product of the reaction, plastohydroquinone (PQH2), is released into the membrane from the QB site, where it is formed. A plastoquinone (PQ) from the membrane pool then binds into the QB site. Despite...
Proceedings of the National Academy of Sciences Biochemistry
12h
PHF2 histone demethylase prevents DNA damage and genome instability by controlling cell cycle progression of neural progenitors [Biochemistry]
Histone H3 lysine 9 methylation (H3K9me) is essential for cellular homeostasis; however, its contribution to development is not well established. Here, we demonstrate that the H3K9me2 demethylase PHF2 is essential for neural progenitor proliferation in vitro and for early neurogenesis in the chicken spinal cord. Using genome-wide analyses and biochemical...
Proceedings of the National Academy of Sciences Biochemistry
12h
A safe and sustainable bacterial cellulose nanofiber separator for lithium rechargeable batteries [Biochemistry]
Bacterial cellulose nanofiber (BCNF) with high thermal stability produced by an ecofriendly process has emerged as a promising solution to realize safe and sustainable materials in the large-scale battery. However, an understanding of the actual thermal behavior of the BCNF in the full-cell battery has been lacking, and the yield...
Proceedings of the National Academy of Sciences Biochemistry
12h
Human papillomavirus E7 oncoprotein targets RNF168 to hijack the host DNA damage response [Cell Biology]
High-risk human papillomaviruses (HR-HPVs) promote cervical cancer as well as a subset of anogenital and head and neck cancers. Due to their limited coding capacity, HPVs hijack the host cell’s DNA replication and repair machineries to replicate their own genomes. How this host–pathogen interaction contributes to genomic instability is unknown....
Proceedings of the National Academy of Sciences Cell Biology
13h
Lgr5+ pericentral hepatocytes are self-maintained in normal liver regeneration and susceptible to hepatocarcinogenesis [Cell Biology]
Emerging evidence suggests that hepatocytes are primarily maintained by self-renewal during normal liver homeostasis, as well as in response to a wide variety of hepatic injuries. However, how hepatocytes in distinct anatomic locations within the liver lobule are replenished under homeostasis and injury-induced regeneration remains elusive. Using a newly developed...
Proceedings of the National Academy of Sciences Cell Biology
13h
Regulation of GSK3 cellular location by FRAT modulates mTORC1-dependent cell growth and sensitivity to rapamycin [Cell Biology]
The mTORC1 pathway regulates cell growth and proliferation by properly coupling critical processes such as gene expression, protein translation, and metabolism to the availability of growth factors and hormones, nutrients, cellular energetics, oxygen status, and cell stress. Although multiple cytoplasmic substrates of mTORC1 have been identified, how mTORC1 signals within...
Proceedings of the National Academy of Sciences Cell Biology
13h
Development and utilization of human decidualization reporter cell line uncovers new modulators of female fertility [Cell Biology]
Failure of embryo implantation accounts for a significant percentage of female infertility. Exquisitely coordinated molecular programs govern the interaction between the competent blastocyst and the receptive uterus. Decidualization, the rapid proliferation and differentiation of endometrial stromal cells into decidual cells, is required for implantation. Decidualization defects can cause poor placentation,...
Proceedings of the National Academy of Sciences Cell Biology
13h
Generalized minimum distance functions and algebraic invariants of Geramita ideals
Publication date: January 2020Source: Advances in Applied Mathematics, Volume 112Author(s): Susan M. Cooper, Alexandra Seceleanu, Ştefan O. Tohăneanu, Maria Vaz Pinto, Rafael H. VillarrealAbstractMotivated by notions from coding theory, we study the generalized minimum distance (GMD) function δI(d,r) of a graded ideal I in a polynomial ring over an arbitrary field using commutative algebraic methods. It is shown that δI is non-decreasing as a function of r and non-increasing as a function of d. For...
Adv. in Applied Math.
13h
The Jordan type of graded Artinian Gorenstein algebras
Publication date: October 2019Source: Advances in Applied Mathematics, Volume 111Author(s): Barbara Costa, Rodrigo GondimAbstractWe study the generic Jordan type of standard graded Artinian Gorenstein algebras, it is a finer invariant than whether the algebra satisfies some of the Lefschetz properties. We prove that their Jordan types are determined by the ranks of certain Mixed Hessians. We determine the possible Jordan types for algebras of low socle degree and codimension.
Adv. in Applied Math.
13h
Improved detection of diffuse glioma infiltration with imaging combinations: a diagnostic accuracy study
AbstractBackgroundSurgical resection and irradiation of diffuse glioma are guided by standard MRI: T2/FLAIR-weighted MRI for non-enhancing and T1-weighted gadolinium-enhanced (T1G) MRI for enhancing gliomas. Amino acid PET has been suggested as new standard. Imaging combinations may improve standard MRI and amino acid PET. The aim of the study was to determine the accuracy of imaging combinations to detect glioma infiltration.MethodsWe included 20 consecutive adults with newly-diagnosed non-enhancing...
Neuro-Oncology - Advance Access
13h
VCAM-1 Targeted Alpha-Particle Therapy for Early Brain Metastases
AbstractBackgroundBrain metastases (BM) develop frequently in patients with breast cancer. Despite the use of external beam radiotherapy (EBRT), the average overall survival is short (6 months from diagnosis). The therapeutic challenge is to deliver molecularly targeted therapy at an early stage when relatively few metastatic tumour cells have invaded the brain. Vascular cell adhesion molecule-1 (VCAM-1), overexpressed by nearby endothelial cells during the early stages of BM development, is a promising...
Neuro-Oncology - Advance Access
13h
Understanding a complicated Gal-1
Neuro-Oncology - Advance Access
13h
Evolution-based screening enables genome-wide prioritization and discovery of DNA repair genes [Genetics]
DNA repair is critical for genome stability and is maintained through conserved pathways. Traditional genome-wide mammalian screens are both expensive and laborious. However, computational approaches circumvent these limitations and are a powerful tool to identify new DNA repair factors. By analyzing the evolutionary relationships between genes in the major DNA...
Proceedings of the National Academy of Sciences Genetics
13h
The Impact of Adaptive Functioning and Oral Hygiene Practices on Observed Tooth-Brushing Performance Among Preschool Children with Special Health Care Needs
Abstract Objectives To investigate the impact of adaptive functioning and oral hygiene practices on tooth-brushing performance among preschool children with special health care needs (SHCN). Methods A cross-sectional study was conducted in Special Child Care Centers. Children’s tooth-brushing performance was assessed by a standardized 13-step pro forma. Information...
Latest Results for Maternal and Child Health Journal
13h
Subcortical connectivity correlates selectively with attention’s effects on spatial choice bias [Psychological and Cognitive Sciences]
Neural mechanisms of attention are extensively studied in the neocortex; comparatively little is known about how subcortical regions contribute to attention. The superior colliculus (SC) is an evolutionarily conserved, subcortical (midbrain) structure that has been implicated in controlling visuospatial attention. Yet how the SC contributes mechanistically to attention remains unknown....
Proceedings of the National Academy of Sciences current issue
13h
Preserved capacity for learning statistical regularities and directing selective attention after hippocampal lesions [Psychological and Cognitive Sciences]
Prior knowledge about the probabilistic structure of visual environments is necessary to resolve ambiguous information about objects in the world. Expectations based on stimulus regularities exert a powerful influence on human perception and decision making by improving the efficiency of information processing. Another type of prior knowledge, termed top-down attention,...
Proceedings of the National Academy of Sciences current issue
13h
Correction for Sever et al., SLAMF9 regulates pDC homeostasis and function in health and disease [Correction]
IMMUNOLOGY AND INFLAMMATION Correction for “SLAMF9 regulates pDC homeostasis and function in health and disease,” by Lital Sever, Lihi Radomir, Kristin Strim, Anna Weiner, Nofar Shchottlender, Hadas Lewinsky, Avital F. Barak, Gilgi Friedlander, Shifra Ben-Dor, Shirly Becker-Herman, and Idit Shachar, which was first published July 25, 2019; 10.1073/pnas.1900079116 (Proc. Natl....
Proceedings of the National Academy of Sciences current issue
13h
Neurodevelopmental mutation of giant ankyrin-G disrupts a core mechanism for axon initial segment assembly [Neuroscience]
Giant ankyrin-G (gAnkG) coordinates assembly of axon initial segments (AISs), which are sites of action potential generation located in proximal axons of most vertebrate neurons. Here, we identify a mechanism required for normal neural development in humans that ensures ordered recruitment of gAnkG and β4-spectrin to the AIS. We identified...
Proceedings of the National Academy of Sciences current issue
13h
Rickettsia conorii O antigen is the target of bactericidal Weil-Felix antibodies [Microbiology]
Rickettsial diseases have long been diagnosed with serum antibodies cross-reactive against Proteus vulgaris (Weil–Felix reaction). Although Weil–Felix antibodies are associated with the development of immunity, their rickettsial target and contribution to disease pathogenesis are not established. Here, we developed a transposon for insertional mutagenesis of Rickettsia conorii, isolating variants defective...
Proceedings of the National Academy of Sciences current issue
13h
NEEDLE1 encodes a mitochondria localized ATP-dependent metalloprotease required for thermotolerant maize growth [Plant Biology]
Meristems are highly regulated structures ultimately responsible for the formation of branches, lateral organs, and stems, and thus directly affect plant architecture and crop yield. In meristems, genetic networks, hormones, and signaling molecules are tightly integrated to establish robust systems that can adapt growth to continuous inputs from the environment....
Proceedings of the National Academy of Sciences current issue
13h
Mode-of-action profiling reveals glutamine synthetase as a collateral metabolic vulnerability of M. tuberculosis to bedaquiline [Microbiology]
Combination chemotherapy can increase treatment efficacy and suppress drug resistance. Knowledge of how to engineer rational, mechanism-based drug combinations, however, remains lacking. Although studies of drug activity have historically focused on the primary drug–target interaction, growing evidence has emphasized the importance of the subsequent consequences of this interaction. Bedaquiline (BDQ)...
Proceedings of the National Academy of Sciences current issue
13h
The single-cell transcriptomic landscape of early human diabetic nephropathy [Medical Sciences]
Diabetic nephropathy is characterized by damage to both the glomerulus and tubulointerstitium, but relatively little is known about accompanying cell-specific changes in gene expression. We performed unbiased single-nucleus RNA sequencing (snRNA-seq) on cryopreserved human diabetic kidney samples to generate 23,980 single-nucleus transcriptomes from 3 control and 3 early diabetic nephropathy...
Proceedings of the National Academy of Sciences current issue
13h
Targeted mobilization of Lrig1+ gastric epithelial stem cell populations by a carcinogenic Helicobacter pylori type IV secretion system [Microbiology]
Helicobacter pylori-induced gastritis is the strongest risk factor for gastric adenocarcinoma, a malignancy preceded by a series of well-defined histological stages, including metaplasia. One microbial constituent that augments cancer risk is the cag type 4 secretion system (T4SS), which translocates the oncoprotein CagA into host cells. Aberrant stem cell activation...
Proceedings of the National Academy of Sciences current issue
13h
Diversification of giant and large eukaryotic dsDNA viruses predated the origin of modern eukaryotes [Evolution]
Giant and large eukaryotic double-stranded DNA viruses from the Nucleo-Cytoplasmic Large DNA Virus (NCLDV) assemblage represent a remarkably diverse and potentially ancient component of the eukaryotic virome. However, their origin(s), evolution, and potential roles in the emergence of modern eukaryotes remain subjects of intense debate. Here we present robust phylogenetic...
Proceedings of the National Academy of Sciences current issue
13h
Chestnut-crowned babbler calls are composed of meaningless shared building blocks [Evolution]
A core component of human language is its combinatorial sound system: meaningful signals are built from different combinations of meaningless sounds. Investigating whether nonhuman communication systems are also combinatorial is hampered by difficulties in identifying the extent to which vocalizations are constructed from shared, meaningless building blocks. Here we present...
Proceedings of the National Academy of Sciences current issue
13h
Oligogalacturonide production upon Arabidopsis thaliana-Botrytis cinerea interaction [Plant Biology]
Despite an ever-increasing interest for the use of pectin-derived oligogalacturonides (OGs) as biological control agents in agriculture, very little information exists—mainly for technical reasons—on the nature and activity of the OGs that accumulate during pathogen infection. Here we developed a sensitive OG profiling method, which revealed unsuspected features of the...
Proceedings of the National Academy of Sciences current issue
13h
RNA editing alterations define manifestation of prion diseases [Neuroscience]
Prion diseases are fatal neurodegenerative disorders caused by misfolding of the normal prion protein into an infectious cellular pathogen. Clinically characterized by rapidly progressive dementia and accounting for 85% of human prion disease cases, sporadic Creutzfeldt–Jakob disease (sCJD) is the prevalent human prion disease. Although sCJD neuropathological hallmarks are well-known,...
Proceedings of the National Academy of Sciences current issue
13h
Intracellular redox potential is correlated with miRNA expression in MCF7 cells under hypoxic conditions [Biophysics and Computational Biology]
Hypoxia is a ubiquitous feature of cancers, encouraging glycolytic metabolism, proliferation, and resistance to therapy. Nonetheless, hypoxia is a poorly defined term with confounding features described in the literature. Redox biology provides an important link between the external cellular microenvironment and the cell’s response to changing oxygen pressures. In this...
Proceedings of the National Academy of Sciences current issue
13h
p53 prevents doxorubicin cardiotoxicity independently of its prototypical tumor suppressor activities [Medical Sciences]
Doxorubicin is a widely used chemotherapeutic agent that causes dose-dependent cardiotoxicity in a subset of treated patients, but the genetic determinants of this susceptibility are poorly understood. Here, we report that a noncanonical tumor suppressor activity of p53 prevents cardiac dysfunction in a mouse model induced by doxorubicin administered in...
Proceedings of the National Academy of Sciences current issue
13h
Large-scale identification of pathogen essential genes during coinfection with sympatric and allopatric microbes [Microbiology]
Recent evidence suggests that the genes an organism needs to survive in an environment drastically differ when alone or in a community. However, it is not known if there are universal functions that enable microbes to persist in a community and if there are functions specific to interactions between microbes...
Proceedings of the National Academy of Sciences current issue
13h
An ensemble of cryo-EM structures of TRiC reveal its conformational landscape and subunit specificity [Biophysics and Computational Biology]
TRiC/CCT assists the folding of ∼10% of cytosolic proteins through an ATP-driven conformational cycle and is essential in maintaining protein homeostasis. Here, we determined an ensemble of cryo-electron microscopy (cryo-EM) structures of yeast TRiC at various nucleotide concentrations, with 4 open-state maps resolved at near-atomic resolutions, and a closed-state map...
Proceedings of the National Academy of Sciences current issue
13h
Phase variation in Mycobacterium tuberculosis glpK produces transiently heritable drug tolerance [Microbiology]
The length and complexity of tuberculosis (TB) therapy, as well as the propensity of Mycobacterium tuberculosis to develop drug resistance, are major barriers to global TB control efforts. M. tuberculosis is known to have the ability to enter into a drug-tolerant state, which may explain many of these impediments to...
Proceedings of the National Academy of Sciences current issue
13h
Immunogenicity of a rheumatoid arthritis protective sequence when acquired through microchimerism [Immunology and Inflammation]
HLA class II genes provide the strongest genetic contribution to rheumatoid arthritis (RA). HLA-DRB1 alleles encoding the sequence DERAA are RA-protective. Paradoxically, RA risk is increased in women with DERAA+ children born prior to onset. We developed a sensitive qPCR assay specific for DERAA, and found 53% of DERAA−/− women...
Proceedings of the National Academy of Sciences current issue
13h
Neurokinin-1 receptor is an effective target for treating leukemia by inducing oxidative stress through mitochondrial calcium overload [Medical Sciences]
Substance P (SP) regulates multiple biological processes through its high-affinity neurokinin-1 receptor (NK-1R). While the SP/NK-1R signaling axis is involved in the pathogenesis of solid cancer, the role of this signaling pathway in hematological malignancy remains unknown. Here, we demonstrate that NK-1R expression is markedly elevated in the white blood...
Proceedings of the National Academy of Sciences current issue
13h

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