ICOS-ligand, expressed on human endothelial cells, costimulates Th1 and Th2 cytokine secretion by memory CD4+ T cells.

abstract：:For several decades, the iron-based Fenton-like catalysis has been believed to be mediated by hydroxyl radicals or high-valent iron-oxo species, while only sporadic evidence supported the generation of singlet oxygen (1O2) in the Haber-Weiss cycle. Herein, we report an unprecedented singlet oxygen mediated Fenton-like...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yang Z,Qian J,Yu A,Pan B

更新日期：2019-04-02 00:00:00

abstract：:Despite their overall accuracy, errors in macromolecular processes, such as rRNA synthesis and ribosome assembly, inevitably occur. However, whether these errors are remediated and how this might be accomplished is not known. In previous work, we showed that a double mutant strain lacking both polynucleotide phosphory...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cheng ZF,Deutscher MP

更新日期：2003-05-27 00:00:00

abstract：:The lack of genetic means has been a serious limitation in studying mosquito immunity. We generated Relish-mediated immune deficiency (RMID) by transforming Aedes aegypti with the Delta Rel transgene driven by the vitellogenin (Vg) promoter using the pBac[3xP3-EGFP, afm] vector. A stable transformed line had a single ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shin SW,Kokoza V,Lobkov I,Raikhel AS

更新日期：2003-03-04 00:00:00

abstract：:Explants of human endometrium were cultured to study the release of matrix metalloproteinases (MMPs). Analysis of conditioned media by zymography revealed latent and active forms of collagenase (MMP-1, EC 3.4.24.7), 72-kDa gelatinase A (MMP-2, EC 3.4.24.24), and 92-kDa gelatinase B (MMP-9, EC 3.4.24.35). These protein...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Marbaix E,Donnez J,Courtoy PJ,Eeckhout Y

更新日期：1992-12-15 00:00:00

abstract：:We have identified a cDNA from a human phytohemagglutinin-activated lymphoblast library encoding a protein that binds 125I-labeled human interleukin 12 (125I-huIL-12) with a Kd of about 5 nM when expressed in COS-7 cells. When coexpressed in COS-7 cells with the previously identified IL-12 beta receptor (IL-12R beta) ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Presky DH,Yang H,Minetti LJ,Chua AO,Nabavi N,Wu CY,Gately MK,Gubler U

更新日期：1996-11-26 00:00:00

abstract：:Ferric uptake regulation protein (Fur) is a bacterial global regulator that uses iron as a cofactor to bind to specific DNA sequences. The function of Fur is not limited to iron homeostasis. A wide variety of genes involved in various mechanisms such as oxidative and acid stresses are under Fur control. Flavohemoglobi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： D'Autreaux B,Touati D,Bersch B,Latour JM,Michaud-Soret I

更新日期：2002-12-24 00:00:00

abstract：:A likely mechanism of chromosomal rearrangement formation involves joining the ends from two different chromosomal double-strand breaks (DSBs). These events could potentially be mediated by either of two end-joining (EJ) repair pathways [canonical nonhomologous end joining (C-NHEJ) or alternative end joining (ALT-EJ)]...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bhargava R,Carson CR,Lee G,Stark JM

更新日期：2017-01-24 00:00:00

abstract：:Proper regulation of the intracellular ion concentration is essential to maintain life and is achieved by ion transporters that transport their substrates across the membrane in a strictly regulated manner. MgtE is a Mg(2+) transporter that may function in the homeostasis of the intracellular Mg(2+) concentration. A r...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ishitani R,Sugita Y,Dohmae N,Furuya N,Hattori M,Nureki O

更新日期：2008-10-07 00:00:00

abstract：:The response of the nematic twist-bend ([Formula: see text]) phase to an applied field can provide important insight into the structure of this liquid and may bring us closer to understanding mechanisms generating mirror symmetry breaking in a fluid of achiral molecules. Here we investigate theoretically how an extern...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Pająk G,Longa L,Chrzanowska A

更新日期：2018-10-30 00:00:00

abstract：:Disease tolerance, the capacity of tissues to withstand damage caused by a stimulus without a decline in host fitness, varies across tissues, environmental conditions, and physiologic states. While disease tolerance is a known strategy of host defense, its role in noninfectious diseases has been understudied. Here, we...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Man K,Bowman C,Braverman KN,Escalante V,Tian Y,Bisanz JE,Ganeshan K,Wang B,Patterson A,Bayrer JR,Turnbaugh PJ,Chawla A

更新日期：2020-12-15 00:00:00

abstract：:In the central nervous system, glycogen-derived bioenergetic resources in astrocytes help promote tissue survival in response to focal neuronal stress. However, our understanding of the extent to which these resources are mobilized and utilized during neurodegeneration, especially in nearby regions that are not active...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cooper ML,Pasini S,Lambert WS,D'Alessandro KB,Yao V,Risner ML,Calkins DJ

更新日期：2020-08-04 00:00:00

abstract：:We have developed an approach for deriving and characterizing antigen-receptor (CD3/Ti) signal-transduction mutants. This strategy combines receptor-mediated growth inhibition and fluorescence-activated cell sorting with the Ca2+-indicator indo-1. Despite the expression of structurally normal CD3/Ti complexes, one suc...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Goldsmith MA,Weiss A

更新日期：1987-10-01 00:00:00

abstract：:In autotrophically grown Chlorella cells, glucose induces a hexose transport system but, at the same time, the synthesis of two amino acid transport systems is also induced. Thus, the rates of uptake of glycine, L-alanine, L-proline, and L-serine, all of which compete with each other for entry into the cells, increase...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cho BH,Sauer N,Komor E,Tanner W

更新日期：1981-06-01 00:00:00

abstract：:Prions are mammalian proteins (PrPs) with a unique pathogenic property: a nonendogenous isoform PrP(Sc) can catalyze conversion of the endogenous PrP(C) isoform into additional PrP(Sc). In this work, we demonstrate that PrP(C) helix 1 has certain properties (hydrophilicity, charge distribution) that make it unique amo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Morrissey MP,Shakhnovich EI

更新日期：1999-09-28 00:00:00

abstract：:The effects of epinephrine (as low as 0.1 muM) on guanosine 3':5'-cyclic monophosphate (cGMP) and adenosine 3':5'-cyclic monophosphate (cAMP) in isolated fat cells were examined. Epinephrine increased both cGMP and cAMP levels, with the elevation of cAMP preceding the rise of cGMP. Maximal elevation was obtained with ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Asakawa T,Ruiz J,Ho RJ

更新日期：1978-06-01 00:00:00

abstract：:Interactions between swimming cells and surfaces are essential to many microbiological processes, from bacterial biofilm formation to human fertilization. However, despite their fundamental importance, relatively little is known about the physical mechanisms that govern the scattering of flagellated or ciliated cells ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kantsler V,Dunkel J,Polin M,Goldstein RE

更新日期：2013-01-22 00:00:00

abstract：:We report on the production of tumor necrosis factor (TNF)-alpha and TNF-beta by mitogen-activated peripheral blood lymphocytes or enriched monocyte subpopulations from human leukocyte antigen (HLA)-typed healthy subjects. The results indicate that HLA-DR2- and DQw1-positive donors frequently exhibit low production of...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Jacob CO,Fronek Z,Lewis GD,Koo M,Hansen JA,McDevitt HO

更新日期：1990-02-01 00:00:00

abstract：:The Pyrococcus furiosus (PF) ornithine carbamoyltransferase (OTCase; EC 2.1.3.3) is an extremely heat-stable enzyme that maintains about 50% of its activity after heat treatment for 60 min at 100 degrees C. To understand the molecular basis of thermostability of this enzyme, we have determined its three-dimensional st...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Villeret V,Clantin B,Tricot C,Legrain C,Roovers M,Stalon V,Glansdorff N,Van Beeumen J

更新日期：1998-03-17 00:00:00

abstract：:Avian leukosis virus subgroup J (ALV-J) is an important concern for the poultry industry. Replication of ALV-J depends on a functional cellular receptor, the chicken Na+/H+ exchanger type 1 (chNHE1). Tryptophan residue number 38 of chNHE1 (W38) in the extracellular portion of this molecule is a critical amino acid for...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Koslová A,Trefil P,Mucksová J,Reinišová M,Plachý J,Kalina J,Kučerová D,Geryk J,Krchlíková V,Lejčková B,Hejnar J

更新日期：2020-01-28 00:00:00

abstract：:The maturation of 5S RNA in Escherichia coli is poorly understood. Although it is known that large precursors of 5S RNA accumulate in mutant cells lacking the endoribonuclease-RNase E, almost nothing is known about how the mature 5' and 3' termini of these molecules are generated. We have examined 5S RNA maturation in...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Li Z,Deutscher MP

更新日期：1995-07-18 00:00:00

abstract：:The Na/K pump is a P-type ATPase that exchanges three intracellular Na(+) ions for two extracellular K(+) ions through the plasmalemma of nearly all animal cells. The mechanisms involved in cation selection by the pump's ion-binding sites (site I and site II bind either Na(+) or K(+); site III binds only Na(+)) are po...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ratheal IM,Virgin GK,Yu H,Roux B,Gatto C,Artigas P

更新日期：2010-10-26 00:00:00

abstract：:YC-1 [3-(5'-hydroxymethyl-2'furyl)-1-benzyl indazole] is an allosteric activator of soluble guanylyl cyclase (sGC). YC-1 increases the catalytic rate of the enzyme and sensitizes the enzyme toward its gaseous activators nitric oxide or carbon monoxide. In other studies the administration of YC-1 to experimental animal...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Martin E,Lee YC,Murad F

更新日期：2001-11-06 00:00:00

abstract：:The transition to pulmonary respiration after birth requires rapid alterations in the structure of the mammalian cardiovascular system. One dramatic change that occurs is the closure of the ductus arteriosus (DA), an arterial connection in the fetus that directs blood flow away from the pulmonary circulation. Two memb...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Levet S,Ouarné M,Ciais D,Coutton C,Subileau M,Mallet C,Ricard N,Bidart M,Debillon T,Faravelli F,Rooryck C,Feige JJ,Tillet E,Bailly S

更新日期：2015-06-23 00:00:00

abstract：:This distance between a base next to the anticodon of tRNA and the 3' CpCpA terminus of the molecule has been estimated by singlet-singlet energy transfer experiments. The energy donor was the Y base of unknown structure found in yeast tRNA(phe). Three different energy acceptors were used: acriflavine, proflavinyl ace...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Beardsley K,Cantor CR

更新日期：1970-01-01 00:00:00

abstract：:Life in environments devoid of photosynthesis, such as on early Earth or in contemporary dark subsurface ecosystems, is supported by chemical energy. How, when, and where chemical nutrients released from the geosphere fuel chemosynthetic biospheres is fundamental to understanding the distribution and diversity of life...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dunham EC,Dore JE,Skidmore ML,Roden EE,Boyd ES

更新日期：2021-01-12 00:00:00

abstract：:Spatial memory enhances an organism's navigational ability. Memory typically resides within the brain, but what if an organism has no brain? We show that the brainless slime mold Physarum polycephalum constructs a form of spatial memory by avoiding areas it has previously explored. This mechanism allows the slime mold...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Reid CR,Latty T,Dussutour A,Beekman M

更新日期：2012-10-23 00:00:00

abstract：:In humans, septal defects are among the most prevalent congenital heart diseases, but their cellular and molecular origins are not fully understood. We report that transcription factor Tbx5 is present in a subpopulation of endocardial cells and that its deletion therein results in fully penetrant, dose-dependent atria...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Nadeau M,Georges RO,Laforest B,Yamak A,Lefebvre C,Beauregard J,Paradis P,Bruneau BG,Andelfinger G,Nemer M

更新日期：2010-11-09 00:00:00

abstract：:Near infrared diffuse optical spectroscopy and diffuse optical imaging are promising methods that eventually may enhance or replace existing technologies for breast cancer screening and diagnosis. These techniques are based on highly sensitive, quantitative measurements of optical and functional contrast between healt...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shah N,Cerussi A,Eker C,Espinoza J,Butler J,Fishkin J,Hornung R,Tromberg B

更新日期：2001-04-10 00:00:00

abstract：:The role of RNA silencing as an antiviral defense mechanism in fungi was examined by testing the effect of dicer gene disruptions on mycovirus infection of the chestnut blight fungus Cryphonectria parasitica. C. parasitica dicer-like genes dcl-1 and dcl-2 were cloned and shown to share a high level of predicted amino ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Segers GC,Zhang X,Deng F,Sun Q,Nuss DL

更新日期：2007-07-31 00:00:00

abstract：:Soluble extracts of adenovirus-infected HeLa cell nuclei support DNA replication on exogenous adenovirus DNA templates. Conditions of synthesis using both wild-type and temperature-sensitive extracts have been defined. Nuclear extracts prepared from cells permissively infected with the adenovirus mutant H5ts125 expres...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kaplan LM,Ariga H,Hurwitz J,Horwitz MS

更新日期：1979-11-01 00:00:00