Laccase detoxification mediates the nutritional alliance between leaf-cutting ants and fungus-garden symbionts.

abstract：:Madagascar periwinkle (Catharanthus roseus) is the sole source of the anticancer drugs vinblastine and vincristine, bisindole alkaloids derived from the dimerization of the terpenoid indole alkaloids vindoline and catharanthine. Full elucidation of the biosynthetic pathways of these compounds is a prerequisite for met...

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

authors： Liscombe DK,Usera AR,O'Connor SE

更新日期：2010-11-02 00:00:00

abstract：:The pleiotropic effect of the sickle gene suggests that factors in addition to polymerization of the mutant gene product might be involved in sickle disease pathobiology. We have examined rates of heme transfer to hemopexin from hemoglobin in dilute aqueous solution (0.5 mg of Hb per ml) at 37 degrees C. HbO2 S loses ...

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

authors： Hebbel RP,Morgan WT,Eaton JW,Hedlund BE

更新日期：1988-01-01 00:00:00

abstract：:Polypeptide chains of 19 previously studied Escherichia coli aminoacyl-tRNA synthetases are as large as 951 amino acids and, depending on the enzyme, have quaternary structures of alpha, alpha 2, alpha 2 beta 2, and alpha 4. These enzymes have been organized into two classes which are defined by sequence motifs that a...

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

authors： Hou YM,Shiba K,Mottes C,Schimmel P

更新日期：1991-02-01 00:00:00

abstract：:The structural analysis of the Fab' fragment of human myeloma immunoglobulin IgGl(lambda) New has been extended to a nominal resolution of 2.0 A. Each of the structural subunits corresponding to the variable and to the constant homology regions of the light and heavy chains contains two irregular beta-sheets which are...

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

authors： Poljak RJ,Amzel LM,Chen BL,Phizackerley RP,Saul F

更新日期：1974-09-01 00:00:00

abstract：:Entorhinal grid cells integrate sensory and self-motion inputs to provide a spatial metric of a characteristic scale. One function of this metric may be to help localize the firing fields of hippocampal place cells during formation and use of the hippocampal spatial representation ("cognitive map"). Of theoretical imp...

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

authors： Casali G,Bush D,Jeffery K

更新日期：2019-03-05 00:00:00

abstract：:Heavy atoms, such as bromine or iodine, perturb the excited-state properties of aromatic chromophores through a spin-orbital coupling mechanism. In the present work the use of specifically directed spin-orbital probes to study subtle structural relationships in biopolymers is described. Heavy atoms are introduced into...

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

authors： Galley WC,Purkey RM

更新日期：1972-08-01 00:00:00

abstract：:Gastrin-releasing peptide (GRP) is a 27-amino acid neuroendocrine hormone that may play a role in the pathophysiology of small cell lung carcinoma. GRP and bombesin, a structurally related peptide, stimulate the growth of some cultured cell types. C-terminal GRP peptide analogs were developed that inhibited 6 nM bombe...

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

authors： Leban JJ,Kull FC Jr,Landavazo A,Stockstill B,McDermed JD

更新日期：1993-03-01 00:00:00

abstract：:Restricted fetal growth is associated with postnatal mortality and morbidity and may be directly related to alterations in the capacity of the placenta to supply nutrients. We proposed previously that imprinted genes can regulate nutrient supply by the placenta. Here, we tested the hypothesis that the insulin-like gro...

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

authors： Sibley CP,Coan PM,Ferguson-Smith AC,Dean W,Hughes J,Smith P,Reik W,Burton GJ,Fowden AL,Constância M

更新日期：2004-05-25 00:00:00

abstract：:The major virulence determinant of the rodent malaria parasite, Plasmodium yoelii, has remained unresolved since the discovery of the lethal line in the 1970s. Because virulence in this parasite correlates with the ability to invade different types of erythrocytes, we evaluated the potential role of the parasite eryth...

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

authors： Otsuki H,Kaneko O,Thongkukiatkul A,Tachibana M,Iriko H,Takeo S,Tsuboi T,Torii M

更新日期：2009-04-28 00:00:00

abstract：:The generation of high-titer, helper-free retroviruses by transient transfection has been achieved by using the highly transfectable 293T cell line into which are stably introduced constructs that express retroviral packaging functions. The resulting ecotropic virus packaging cell line BOSC 23 produces infectious retr...

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

authors： Pear WS,Nolan GP,Scott ML,Baltimore D

更新日期：1993-09-15 00:00:00

abstract：:Microcalcifications geographically target the location of abnormalities within the breast and are of critical importance in breast cancer diagnosis. However, despite stereotactic guidance, core needle biopsy fails to retrieve microcalcifications in up to 15% of patients. Here, we introduce an approach based on diffuse...

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

authors： Soares JS,Barman I,Dingari NC,Volynskaya Z,Liu W,Klein N,Plecha D,Dasari RR,Fitzmaurice M

更新日期：2013-01-08 00:00:00

abstract：:The tissue-specific, cell-aggregating component of embryonic neural retina cells was purified from the retina cell-aggregating factor and characterized as a glycoprotein. Its molecular weight in solution is in the range of 50,000, and it contains 10-15% carbohydrate. The amino-acid and carbohydrate compositions have b...

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

authors： Hausman RE,Moscona AA

更新日期：1975-03-01 00:00:00

abstract：:We report on the location of the chain part of the retinylidene chromophore in the projected density of bacteriorhodopsin as determined by neutron diffraction from the two-dimensional purple membrane lattice. For this purpose, partially deuterated retinal was synthesized containing 10 deuterons at positions C-8, C-10,...

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

authors： Seiff F,Wallat I,Ermann P,Heyn MP

更新日期：1985-05-01 00:00:00

abstract：:HLA-G is the putative natural killer (NK) cell inhibitory ligand expressed on the extravillous cytotrophoblast of the human placenta. Killing of the class I negative human B cell line 721.221 by NK cells is inhibited by the expression of HLA-G. This inhibition is dependent on a high level of HLA-G expression. In the p...

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

authors： Mandelboim O,Pazmany L,Davis DM,Valés-Gómez M,Reyburn HT,Rybalov B,Strominger JL

更新日期：1997-12-23 00:00:00

abstract：:The pore domain of voltage-gated potassium (Kv) channels consists of transmembrane helices S5 and S6, the turret, the pore helix, the selectivity filter, and the loop preceding S6, with a tertiary reentrant structure between S5 and S6. Using biogenic intermediates, mass tagging (pegylation), and a molecular tape measu...

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

authors： Gajewski C,Dagcan A,Roux B,Deutsch C

更新日期：2011-02-22 00:00:00

abstract：:Regulation of hexose transport in NIL hamster fibroblasts has been studied in confluent cultures preconditioned for 24 hr in media deprived of glutamine or of serum or of both. Cultures maintained in media containing dialyzed fetal calf serum and 4 mM glutamine accumulated up to 72 nmol of glutamine per mg of cell pro...

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

authors： Kalckar HM,Ullrey DB,Laursen RA

更新日期：1980-10-01 00:00:00

abstract：:Because previous studies showed that polyunsaturated fatty acids can reduce the contraction rate of spontaneously beating heart cells and have antiarrhythmic effects, we examined the effects of the fatty acids on the electrophysiology of the cardiac cycle in isolated neonatal rat cardiac myocytes. Exposure of cardiomy...

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

authors： Kang JX,Xiao YF,Leaf A

更新日期：1995-04-25 00:00:00

abstract：:Cytotoxic T lymphocytes (CTLs) recognize antigens in the context of major histocompatibility complex (MHC) class I gene products. The T-cell receptor (TCR) that mediates this MHC-restricted antigen recognition recognizes short peptide fragments rather than the intact antigen. Presentation of peptides to the TCR may th...

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

authors： Kievits F,Wijffels J,Lokhorst W,Ivanyi P

更新日期：1989-01-01 00:00:00

abstract：:Left-right (LR) asymmetry (handedness, chirality) is a well-conserved biological property of critical importance to normal development. Changes in orientation of the LR axis due to genetic or environmental factors can lead to malformations and disease. While the LR asymmetry of organs and whole organisms has been exte...

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

authors： Wan LQ,Ronaldson K,Park M,Taylor G,Zhang Y,Gimble JM,Vunjak-Novakovic G

更新日期：2011-07-26 00:00:00

abstract：:Evidence from three studies reveals a critical difference in self-control as a function of political ideology. Specifically, greater endorsement of political conservatism (versus liberalism) was associated with greater attention regulation and task persistence. Moreover, this relationship is shown to stem from varying...

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

authors： Clarkson JJ,Chambers JR,Hirt ER,Otto AS,Kardes FR,Leone C

更新日期：2015-07-07 00:00:00

abstract：:Enkephalins, a group of small peptides with opiate-like activity, have been defined originally as neuropeptides. Recent reports showed, using in situ hybridization, that the enkephalin-encoding gene, proenkephalin A (pEnkA), is expressed in nondifferentiated cells of diverse mesodermal lineages. The transient expressi...

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

authors： Rosen H,Polakiewicz RD,Benzakine S,Bar-Shavit Z

更新日期：1991-05-01 00:00:00

abstract：:Linear porphyrin arrays self-assembled by either hydrogen bonding or metal ion coordination self-organize into lipid bilayer membranes. The length of the transmembrane assemblies is determined both by the thermodynamics of the intermolecular interactions in the supermolecule and by the dimension and physical chemical ...

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

authors： Drain CM

更新日期：2002-04-16 00:00:00

abstract：:The prefrontal cortex plays a fundamental role in the working memory functions of the cerebral cortex and is also the site of dysfunction in several neurological and psychiatric disorders, including schizophrenia. Prefrontal neurons are distinguished by their capacity for sustained activity during the time a stimulus ...

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

authors： Gao WJ,Krimer LS,Goldman-Rakic PS

更新日期：2001-01-02 00:00:00

abstract：:Contact-dependent growth inhibition (CDI) is a mechanism by which bacteria exchange toxins via direct cell-to-cell contact. CDI systems are distributed widely among Gram-negative pathogens and are thought to mediate interstrain competition. Here, we describe tsf mutations that alter the coiled-coil domain of elongatio...

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

authors： Jones AM,Garza-Sánchez F,So J,Hayes CS,Low DA

更新日期：2017-03-07 00:00:00

abstract：:A recently discovered family of natural anion channelrhodopsins (ACRs) have the highest conductance among channelrhodopsins and exhibit exclusive anion selectivity, which make them efficient inhibitory tools for optogenetics. We report analysis of flash-induced absorption changes in purified wild-type and mutant ACRs,...

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

authors： Sineshchekov OA,Li H,Govorunova EG,Spudich JL

更新日期：2016-04-05 00:00:00

abstract：:Hybridization in plants leads to transinteractions between the parental genomes and epigenomes that can result in changes to both 24 nt siRNA and cytosine methylation ((m)C) levels in the hybrid. In Arabidopsis the principle processes altering the hybrid methylome are Trans Chromosomal Methylation (TCM) and Trans Chro...

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

authors： Greaves IK,Groszmann M,Wang A,Peacock WJ,Dennis ES

更新日期：2014-02-04 00:00:00

abstract：:The nucleotide sequence of mitochondrial DNA of a cytoplasmic "petite" mutant of Saccharomyces cerevisiae is reported. The DNA has a repeat length of 1060 base pairs and contains a genetic marker (oli-1) for the ATPase proteolipid. The nucleotide sequence reveals the presence of part of the structural gene of the subu...

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

authors： Macino G,Tzagoloff A

更新日期：1979-01-01 00:00:00

abstract：:When long polymers such as DNA are in a highly concentrated state they may become entangled, leading to restricted self-diffusion. Here, we investigate the effect of molecular topology on diffusion in concentrated DNA solutions and find surprisingly large effects, even with molecules of modest length and concentration...

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

authors： Robertson RM,Smith DE

更新日期：2007-03-20 00:00:00

abstract：:Neurons in macaque ventral premotor cortex and inferior parietal lobe discharge during both the observation and the execution of motor acts. It has been claimed that these so-called mirror neurons form the basis of action understanding by matching the visual input with the corresponding motor program (direct matching)...

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

authors： Lingnau A,Gesierich B,Caramazza A

更新日期：2009-06-16 00:00:00

abstract：:The morbidity and mortality associated with Vibrio-mediated waterborne diseases necessitates the development of sensitive detection technologies that are able to elucidate the identity, potential pathogenicity, susceptibility, and viability of contaminating bacteria in a timely manner. For this purpose, we have design...

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

authors： Vora GJ,Meador CE,Bird MM,Bopp CA,Andreadis JD,Stenger DA

更新日期：2005-12-27 00:00:00