A multiply convergent platform for the synthesis of trioxacarcins.

abstract：:cGMP is a second messenger that mediates numerous metabolic events; in the present work a role in myeloid cell differentiation was demonstrated. Nitroprusside and NaNO2, which activate cytosolic guanylate cyclase and increase the intracellular cGMP concentration, induced granulocytic differentiation of the human promy...

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

authors： Boss GR

更新日期：1989-09-01 00:00:00

abstract：:Population growth rate is a fundamental ecological and evolutionary characteristic of living organisms, but individuals must balance the metabolism devoted to biosynthesis and reproduction against the maintenance of existing structure and other functionality. Here we present a mathematical model that relates metabolic...

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

authors： Kempes CP,Dutkiewicz S,Follows MJ

更新日期：2012-01-10 00:00:00

abstract：:A mutant of E. coli defective in DNA polymerase II activity was isolated. Extracts had about 0.1% of the normal activity of the DNA polymerase. The effect of the mutation on the ability of cells to replicate DNA of various sources was analyzed. Mutant bacteria grow normally, at 41 degrees as well as at 30 degrees . Al...

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

authors： Hirota Y,Gefter M,Mindich L

更新日期：1972-11-01 00:00:00

abstract：:"Functional connectivity" techniques are commonplace tools for studying brain organization. A critical element of these analyses is to distinguish variance due to neurobiological signals from variance due to nonneurobiological signals. Multiecho fMRI techniques are a promising means for making such distinctions based ...

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

authors： Power JD,Plitt M,Gotts SJ,Kundu P,Voon V,Bandettini PA,Martin A

更新日期：2018-02-27 00:00:00

abstract：:Interphotoreceptor retinoid-binding protein (IRBP) has been hypothesized to function as an intercellular shuttle in the vertebrate eye, serving to transport retinoids between the retinal pigment epithelium (RPE) and photoreceptors in the process by which visual pigment is regenerated after photolysis. This hypothesis ...

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

authors： Okajima TI,Pepperberg DR,Ripps H,Wiggert B,Chader GJ

更新日期：1990-09-01 00:00:00

abstract：:Across phyla, the ribosomes-the central molecular machines for translation of genetic information-exhibit an overall preserved architecture and a conserved functional core. The natural heterogeneity of the ribosome periodically phases a debate on their functional specialization and the tissue-specific variations of th...

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

authors： Amirbeigiarab S,Kiani P,Velazquez Sanchez A,Krisp C,Kazantsev A,Fester L,Schlüter H,Ignatova Z

更新日期：2019-11-05 00:00:00

abstract：:Tridecaptin A1 (TriA1) is a nonribosomal lipopeptide with selective antimicrobial activity against Gram-negative bacteria. Here we show that TriA1 exerts its bactericidal effect by binding to the bacterial cell-wall precursor lipid II on the inner membrane, disrupting the proton motive force. Biochemical and biophysic...

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

authors： Cochrane SA,Findlay B,Bakhtiary A,Acedo JZ,Rodriguez-Lopez EM,Mercier P,Vederas JC

更新日期：2016-10-11 00:00:00

abstract：:The high resolution 1H and 31P NMR spectra of the (dG-dC)8 duplex have been recorded in low- and high-salt solutions in order to evaluate the structural aspects of the salt-induced transition of oligo(dG-dC) in solution [Pohl, F. M. & Jovin, T. M. (1972) J. Mol. Biol. 67, 375-396]. The NMR data require that the (dG-d...

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

authors： Patel DJ,Canuel LL,Pohl FM

更新日期：1979-06-01 00:00:00

abstract：:The "kindling" phenomenon is associated with long-lasting facilitation of synaptic transmission. A possible mechanism of such facilitation could involve changes in the number of synaptic contacts. However, previous attempts to demonstrate a synaptic morphological alteration that could account for the long-term effects...

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

authors： Geinisman Y,Morrell F,deToledo-Morrell L

更新日期：1988-05-01 00:00:00

abstract：:Vibrio cholerae serogroup O139 emerged on the Indian subcontinent in October 1992 to become the first non-O1 V. cholerae serogroup documented to cause epidemic cholera. Although related to V. cholerae El Tor O1 strains, O139 strains have unique surface structures that include a capsular surface layer and lipopolysacch...

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

authors： Waldor MK,Colwell R,Mekalanos JJ

更新日期：1994-11-22 00:00:00

abstract：:In adult rodents, neurons are continually generated in the subventricular zone of the forebrain, from where they migrate tangentially toward the olfactory bulb, the only known target for these neuronal precursors. Within the main olfactory bulb, they ascend radially into the granule and periglomerular cell layers, whe...

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

authors： Gheusi G,Cremer H,McLean H,Chazal G,Vincent JD,Lledo PM

更新日期：2000-02-15 00:00:00

abstract：:Extracellular vesicles (EVs) secreted by cells present an attractive strategy for developing new therapies, but progress in the field is limited by several issues: The quality of the EVs varies with the type and physiological status of the producer cells; protocols used to isolate the EVs are difficult to scale up; an...

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

authors： Kim DK,Nishida H,An SY,Shetty AK,Bartosh TJ,Prockop DJ

更新日期：2016-01-05 00:00:00

abstract：:Learning the properties of an image associated with human gaze placement is important both for understanding how biological systems explore the environment and for computer vision applications. There is a large literature on quantitative eye movement models that seeks to predict fixations from images (sometimes termed...

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

authors： Kümmerer M,Wallis TS,Bethge M

更新日期：2015-12-29 00:00:00

abstract：:Childhood exposure to low-level lead can permanently reduce intelligence, but the neurobiologic mechanism for this effect is unknown. We examined the impact of lead exposure on the development of cortical columns, using the rodent barrel field as a model. In all areas of mammalian neocortex, cortical columns constitut...

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

authors： Wilson MA,Johnston MV,Goldstein GW,Blue ME

更新日期：2000-05-09 00:00:00

abstract：:In contrast to the immunosuppressive potential of UVB (280-320 nm) radiation in experimental animals and humans, UVA (320-400 nm) radiation at environmentally relevant doses appears to be immunologically inert. However, such exposure to UVA radiation has been observed unexpectedly to induce resistance to UVB-induced i...

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

authors： Reeve VE,Tyrrell RM

更新日期：1999-08-03 00:00:00

abstract：:Because the insolubility of the scrapie prion protein (PrP(Sc)) has frustrated structural studies by x-ray crystallography or NMR spectroscopy, we used electron crystallography to characterize the structure of two infectious variants of the prion protein. Isomorphous two-dimensional crystals of the N-terminally trunca...

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

authors： Wille H,Michelitsch MD,Guenebaut V,Supattapone S,Serban A,Cohen FE,Agard DA,Prusiner SB

更新日期：2002-03-19 00:00:00

abstract：:A cDNA library derived from human cerebral cortex was screened for the presence of sodium channel alpha subunit-specific clones. Ligation of three overlapping clones generated a full-length cDNA clone, HBA, that provided the complete nucleotide sequence coding for a protein of 2005 amino acids. The predicted structure...

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

authors： Ahmed CM,Ware DH,Lee SC,Patten CD,Ferrer-Montiel AV,Schinder AF,McPherson JD,Wagner-McPherson CB,Wasmuth JJ,Evans GA

更新日期：1992-09-01 00:00:00

abstract：:ATP is copackaged and coreleased with adrenergic, serotonergic, and cholinergic neurotransmitters, suggesting a possible interaction between the signaling pathways for ATP and these coreleased neurotransmitters. Muscarinic m2 and m4, alpha 2-adrenergic, and D2-dopaminergic neurotransmitter receptors, which have in com...

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

authors： Felder CC,Williams HL,Axelrod J

更新日期：1991-08-01 00:00:00

abstract：:Secreted parasitism proteins encoded by parasitism genes expressed in esophageal gland cells mediate infection and parasitism of plants by root-knot nematodes (RKN). Parasitism gene 16D10 encodes a conserved RKN secretory peptide that stimulates root growth and functions as a ligand for a putative plant transcription ...

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

authors： Huang G,Allen R,Davis EL,Baum TJ,Hussey RS

更新日期：2006-09-26 00:00:00

abstract：:Viruses have been implicated in the development of neurodegenerative diseases, such as Alzheimer's, Parkinson's, and multiple sclerosis. Human herpesvirus-6 (HHV-6) is a neurotropic virus that has been associated with a wide variety of neurologic disorders, including encephalitis, mesial temporal lobe epilepsy, and mu...

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

authors： Harberts E,Yao K,Wohler JE,Maric D,Ohayon J,Henkin R,Jacobson S

更新日期：2011-08-16 00:00:00

abstract：:A bone-resorbing factor, comparable to the osteoclast-activating factor (OAF) produced from peripheral blood leukocytes, is shown to be produced by murine spleen cells activated with the T-cell mitogen Con A. Murine OAF is demonstrated here as being a product of the interaction between thymus-derived T lymphocytes and...

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

authors： Horowitz M,Vignery A,Gershon RK,Baron R

更新日期：1984-04-01 00:00:00

abstract：:Glu-126 (helix IV) and Arg-144 (helix V) are charge paired and play a critical role in substrate binding in the lactose permease of Escherichia coli. When Glu-126 is replaced with Asp, the permease has relatively high activity, implying that helix V has sufficient flexibility to allow Arg-144 to accommodate the decrea...

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

authors： Weinglass AB,Kaback HR

更新日期：1999-09-28 00:00:00

abstract：:We explored the conformational landscape of the proteinogenic amino acid serine [CH(2)OH CH(NH(2)) COOH] in the gas phase. Solid serine was vaporized by laser ablation, expanded in a supersonic jet, and characterized by Fourier transform microwave spectroscopy. In the isolation conditions of the jet there have been di...

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

authors： Blanco S,Sanz ME,López JC,Alonso JL

更新日期：2007-12-18 00:00:00

abstract：:An unprecedented, spontaneous, and complete cleavage of the triple bond of N2 in the thermal reaction of 15N2 with Ta214N+ was observed experimentally by Fourier transform ion cyclotron resonance mass spectrometry; mechanistic aspects of the degenerate ligand exchange were addressed by high-level quantum chemical calc...

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

authors： Geng C,Li J,Weiske T,Schwarz H

更新日期：2019-10-22 00:00:00

abstract：:Pentameric ligand-gated ion channels (pLGICs), which mediate chemo-electric signal transduction in animals, have been recently found in bacteria. Despite clear sequence and 3D structure homology, the phylogenetic distance between prokaryotic and eukaryotic homologs suggests significant structural divergences, especial...

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

authors： Duret G,Van Renterghem C,Weng Y,Prevost M,Moraga-Cid G,Huon C,Sonner JM,Corringer PJ

更新日期：2011-07-19 00:00:00

abstract：:Learning theories hypothesize specific circuits encode essential information for performance. For simple tasks in invertebrates and mammals, the essential circuits are known, but for cognitive functions, the essential circuits remain unidentified. Here, we show that some essential information for performing a choice t...

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

authors： Zhang GR,Cao H,Kong L,O'Brien J,Baughns A,Jan M,Zhao H,Wang X,Lu XG,Cook RG,Geller AI

更新日期：2010-08-10 00:00:00

abstract：:Appropriate hematopoietic stem cell (HSC) self-renewal reflects the tight regulation of cell cycle entry and lineage commitment. Here, we show that Id1, a dominant-negative regulator of E protein transcription factors, maintains HSC self-renewal by preserving the undifferentiated state. Id1-deficient HSCs show increas...

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

authors： Jankovic V,Ciarrocchi A,Boccuni P,DeBlasio T,Benezra R,Nimer SD

更新日期：2007-01-23 00:00:00

abstract：:K+ channels, which have been linked to regulation of electrogenic solute transport as well as Ca2+ influx, represent a locus in hepatocytes for the concerted actions of hormones that employ Ca2+ and cAMP as intracellular messengers. Despite considerable study, the single-channel basis for synergistic effects of Ca2+ a...

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

authors： Lidofsky SD

更新日期：1995-07-18 00:00:00

abstract：:All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O(6)-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O(6)-methylguanine (O(6)MeG) and O(6)-chloroethylguanine (O(6)CEG) specifically initiate apoptosis in...

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

authors： Hickman MJ,Samson LD

更新日期：1999-09-14 00:00:00

abstract：:The integrase protein of human immunodeficiency virus type 1 is necessary for the stable integration of the viral genome into host DNA. Integrase catalyzes the 3' processing of the linear viral DNA and the subsequent DNA strand transfer reaction that inserts the viral DNA ends into host DNA. Although full-length integ...

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

authors： Jenkins TM,Hickman AB,Dyda F,Ghirlando R,Davies DR,Craigie R

更新日期：1995-06-20 00:00:00