Abstract:
:In the mammalian central nervous system, the excitatory amino acid transmitter L-glutamate activates three pharmacologically distinguishable receptors, the N-methyl-D-aspartate (NMDA), kainate, and quisqualate receptors. The present paper addresses the issue of whether these three receptors operate independent channels or whether they share channels that may have several conductance substates. The Xenopus oocyte provides a system for expression of exogenous mRNAs that permits detailed study of receptor structure and function. In oocytes injected with rat brain mRNA, NMDA has a stoichiometry of channel activation different from that for kainate and quisqualate. NMDA activates its own channels as indicated by simple summation or near-summation of currents evoked by NMDA with those evoked by quisqualate or kainate. Deviations from summation are ascribable to lack of selectivity in which an agonist at one receptor acts as a weak antagonist at another receptor. A further indication of separate channels is that block of NMDA channels by Mg2+ or phencyclidine has no effect on kainate or quisqualate responses evoked during the block. Interactions of kainate and quisqualate are more complex, but they can be explained by lack of complete specificity of these agonists for their own receptors.
journal_name
Proc Natl Acad Sci U S Aauthors
Lerma J,Kushner L,Zukin RS,Bennett MVdoi
10.1073/pnas.86.6.2083subject
Has Abstractpub_date
1989-03-01 00:00:00pages
2083-7issue
6eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::The crystal structure of the murine Fab S-20-4 from a protective anti-cholera Ab specific for the lipopolysaccharide Ag of the Ogawa serotype has been determined in its unliganded form and in complex with synthetic fragments of the Ogawa O-specific polysaccharide (O-SP). The upstream terminal O-SP monosaccharide is sh...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.060022997
更新日期:2000-07-18 00:00:00
abstract::Reinstatement of neural activity is hypothesized to underlie our ability to mentally travel back in time to recover the context of a previous experience. We used intracranial recordings to directly examine the precise spatiotemporal extent of neural reinstatement as 32 participants with electrodes placed for seizure m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1073/pnas.1417017112
更新日期:2014-12-30 00:00:00
abstract::Both neocortical and hippocampal networks organize the firing patterns of their neurons by prominent oscillations during sleep, but the functional role of these rhythms is not well understood. Here, we show a robust correlation of neuronal discharges between the somatosensory cortex and hippocampus on both slow and fi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0437938100
更新日期:2003-02-18 00:00:00
abstract::Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic that is a serious global health problem. Evasion of IFN-mediated antiviral signaling is a common defense strategy that pathogenic viruses use to replicate and propagate in the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2016650117
更新日期:2020-11-10 00:00:00
abstract::Some monocytes normally take up residence in tissues as sessile macrophages, but others differentiate into migratory cells resembling dendritic cells that emigrate to lymph nodes. In an in vitro model of a vessel wall, lipid mediators lysophosphatidic acid and platelet-activating factor, whose signals are implicated i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0403259101
更新日期:2004-08-10 00:00:00
abstract::Expansion of polyglutamine repeats in several unrelated proteins causes neurodegenerative diseases with distinct but related pathologies. To provide a model system for investigating common pathogenic features, we have examined the behavior of polyglutamine expansions expressed in Caenorhabditis elegans. The expression...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.100107297
更新日期:2000-05-23 00:00:00
abstract::Although much of the brain's functional organization is genetically predetermined, it appears that some noninnate functions can come to depend on dedicated and segregated neural tissue. In this paper, we describe a series of experiments that have investigated the neural development and organization of one such noninna...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.95.3.847
更新日期:1998-02-03 00:00:00
abstract::Retrieval of recently acquired declarative memories depends on the hippocampus, but with time, retrieval is increasingly sustainable by neocortical representations alone. This process has been conceptualized as system-level consolidation. Using functional magnetic resonance imaging, we assessed over the course of thre...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0507774103
更新日期:2006-01-17 00:00:00
abstract::The non-long terminal repeat (LTR) retrotransposon, R2, encodes a sequence-specific endonuclease responsible for its insertion at a unique site in the 28S rRNA genes of arthropods. Although most non-LTR retrotransposons encode an apurinic-like endonuclease upstream of a common reverse transcriptase domain, R2 and many...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.14.7847
更新日期:1999-07-06 00:00:00
abstract::The environmental backdrop to the evolution and spread of early Homo sapiens in East Africa is known mainly from isolated outcrops and distant marine sediment cores. Here we present results from new scientific drill cores from Lake Malawi, the first long and continuous, high-fidelity records of tropical climate change...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0703874104
更新日期:2007-10-16 00:00:00
abstract::The yeast SIN1 protein is a nuclear protein that together with other proteins behaves as a transcriptional repressor of a family of genes. In addition, sin1 mutants are defective in proper mitotic chromosome segregation. In an effort to understand the basis for these phenotypes, we employed the yeast two-hybrid system...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.16.8274
更新日期:1996-08-06 00:00:00
abstract::In humans, spontaneous movements are often preceded by early brain signals. One such signal is the readiness potential (RP) that gradually arises within the last second preceding a movement. An important question is whether people are able to cancel movements after the elicitation of such RPs, and if so until which po...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1513569112
更新日期:2016-01-26 00:00:00
abstract::The catalytic cycle of the ATP/Mg(2+)-dependent enzyme beta-lactam synthetase (beta-LS) from Streptomyces clavuligerus has been observed through a series of x-ray crystallographic snapshots. Chemistry is initiated by the ordered binding of ATP/Mg(2+) and N(2)-(carboxyethyl)-l-arginine (CEA) to the apoenzyme. The apo a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.232361199
更新日期:2002-11-12 00:00:00
abstract::Host factor protein Cyclophilin A (CypA) regulates HIV-1 viral infectivity through direct interactions with the viral capsid, by an unknown mechanism. CypA can either promote or inhibit viral infection, depending on host cell type and HIV-1 capsid (CA) protein sequence. We have examined the role of conformational dyna...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1516920112
更新日期:2015-11-24 00:00:00
abstract::Strong, short-ranged positional correlations involving counterions can induce a net attractive force between negatively charged strands of DNA and lead to the formation of ion pairs in dilute ionic solutions. However, the long range of the Coulomb interactions impedes the development of a simple local picture. We addr...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0600282103
更新日期:2006-05-16 00:00:00
abstract::Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease in the tropics and subtropics with high morbidity and mortality. The facultative intracellular bacterium induces host cell fusion through its type VI secretion system 5 (T6SS5) as an important part of its pathogenesis in mammalian h...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2006908117
更新日期:2020-07-07 00:00:00
abstract::Expression of the breast and ovarian cancer susceptibility gene BRCA1 is down-regulated in sporadic breast and ovarian cancer cases. Therefore, the identification of genes involved in the regulation of BRCA1 expression might lead to new insights into the pathogenesis and treatment of these tumors. In the present study...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.98.1.130
更新日期:2001-01-02 00:00:00
abstract::Converging TGF-beta and insulin-like neuroendocrine signaling pathways regulate whether Caenorhabditis elegans develops reproductively or arrests at the dauer larval stage. We examined whether neurotransmitters act in the dauer entry or recovery pathways. Muscarinic agonists promote recovery from dauer arrest induced ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.97.1.460
更新日期:2000-01-04 00:00:00
abstract::Vanadyl sulfate and sodium orthovanadate in the concentration range between 5 and 50 microM are shown to be mitogenic for quiescent cultures of Swiss mouse 3T3 and 3T6 cells. The compounds caused a striking shift in the dose-response for the effect of serum on [3H]thymidine incorporation and DNA synthesis. In the abse...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.20.6162
更新日期:1983-10-01 00:00:00
abstract::In epithelia, a primary damage of tight junctions (TJ) always leads to a secondary disruption of adherens junction (AJ), and vice versa. This response, if occurring in the testis, would disrupt spermatogenesis because the blood-testis barrier (BTB) must remain intact during the transit of spermatids in the seminiferou...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1001823107
更新日期:2010-06-22 00:00:00
abstract::Alzheimer beta/A4 amyloid precursor protein (APP) has been suggested to play a central role in the pathogenesis of Alzheimer disease. We have measured the content of different species of APP holoprotein and carboxyl-terminal fragments in human brains from young individuals, nondemented aged individuals, and aged indiv...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.20.8910
更新日期:1991-10-15 00:00:00
abstract::The human chemokine receptors CCR5 and CXCR4 have emerged as the predominant cofactors, along with CD4, for cellular entry of HIV-1 in vivo whereas the contribution of other chemokine receptors to HIV disease has not been yet determined. CCR5-specific (R5) viruses predominate during primary HIV-1 infection whereas vir...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.2.663
更新日期:1999-01-19 00:00:00
abstract::The genetic code in a eukaryotic system has been expanded by the engineering of Escherichia coli tyrosyl-tRNA synthetase (TyrRS) with the Y37V and Q195C mutations (37V195C), which specifically recognize 3-iodo-L-tyrosine rather than L-tyrosine. In the present study, we determined the 3-iodo-L-tyrosine- and L-tyrosine-...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0407039102
更新日期:2005-02-01 00:00:00
abstract::Mononucleated myogenic cells from 11-day-old chicken embryos were infected with tsLA24 or tsNY68, temperature-sensitive transformation mutants of Rous sarcoma virus. The infected mononucleated myogenic cells were incubated at the nonpermissive temperature (41 degrees C) and allowed to develop into multinucleated myotu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.11.5501
更新日期:1978-11-01 00:00:00
abstract::Cysteine site-directed mutagenesis was used to create variants of Escherichia coli ribosomal protein L7/L12 that have single cysteine substitutions, at residues 63 or 89, located in different exposed loops in the structure of the globular C-terminal domain indicated by the crystallographic structure. That structure sh...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.21.9828
更新日期:1993-11-01 00:00:00
abstract::The translocation from chromosome 8 to chromosome 21, t(8;21), associated with acute myeloid leukemia results in production of an AML1/MTG8(ETO) fusion transcript. The product of the AML1 gene contains an evolutionarily conserved 128-amino acid region referred to as the "Runt domain," which is necessary for binding to...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.24.11723
更新日期:1994-11-22 00:00:00
abstract::The hereditary hearing-vision loss disease Usher syndrome (USH) is caused by defects in several proteins, most of which form an integrated protein network called Usher interactome. Harmonin/Ush1C is a master scaffold in the assembly of the Usher protein complexes, because harmonin is known to bind to every protein in ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0901819106
更新日期:2009-04-07 00:00:00
abstract::In an autoshaping experiment, food-deprived pigeons pecked rapidly at a moving dot that preceded the delivery of food. When the moving dot and food were no longer correlated, the rate of pecking dropped nearly to zero. When, subsequently, no food was given, pecking reappeared at a high rate (nearly 200 pecks per min f...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.10.6251
更新日期:1980-10-01 00:00:00
abstract::Recent studies have shown that human cytomegalovirus (HCMV) can induce a robust increase in lipid synthesis which is critical for the success of infection. In mammalian cells the central precursor for lipid biosynthesis, cytosolic acetyl CoA (Ac-CoA), is produced by ATP-citrate lyase (ACLY) from mitochondria-derived c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1614268114
更新日期:2017-02-21 00:00:00
abstract::In human adults, learning and memory under acute stress are characterized by an increased use of rigid habitual response strategies at the cost of flexible cognitive strategies. The immediate effects of stress on cognitive functioning early in life are not well understood. Here we show experimentally that acute stress...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章
doi:10.1073/pnas.1508345112
更新日期:2015-10-13 00:00:00