Abstract:
:The pineal organ of the lizard Anolis carolinensis can be maintained for up to 10 days in superfused organ culture. During this time it synthesizes and releases melatonin into the medium flowing slowly over it. Collection of timed aliquots of medium and subsequent analysis for melatonin by radioimmunoassay reveal circadian rhythms of melatonin output by the isolated pineal. These rhythms persist for many cycles in constant darkness and at several constant ambient temperatures ranging from 22 to 37 degrees C. The period of the rhythm is temperature compensated (Q10 approximately equal to 1.14) and the rhythm is synchronized by light-dark cycles imposed on the cultured gland. This isolated vertebrate organ displays the three major properties of circadian systems and must therefore contain one or more circadian oscillators.
journal_name
Proc Natl Acad Sci U S Aauthors
Menaker M,Wisner Sdoi
10.1073/pnas.80.19.6119subject
Has Abstractpub_date
1983-10-01 00:00:00pages
6119-21issue
19eissn
0027-8424issn
1091-6490journal_volume
80pub_type
杂志文章abstract::Recent epidemiological studies indicate beneficial effects of moderate ethanol consumption in ischemic heart disease. Most studies, however, focus on the effect of long-term consumption of ethanol. In this study, we determined whether brief exposure to ethanol immediately before ischemia also produces cardioprotection...
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.96.22.12784
更新日期:1999-10-26 00:00:00
abstract::When yeast from the early stages of meiosis are transferred from sporulation to growth medium, they can reenter the mitotic cell cycle directly. In contrast, cells from later stages of meiosis (after the initiation of the first nuclear division) will complete meiosis and sporulation despite the shift to growth medium,...
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.91.14.6559
更新日期:1994-07-05 00:00:00
abstract::Mouse granulocyte-macrophage progenitor cells were stimulated to divide by the granulocyte-macrophage colony-stimulating factor (GM-CSF). The two daughter cells were separated; one daughter was transferred to medium containing a high concentration of GM-CSF, the other to medium containing a low concentration. Daughter...
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.77.9.5327
更新日期:1980-09-01 00:00:00
abstract::Coiled-coil motifs are ubiquitous mediators of specific protein-protein interactions through the formation of interlocking hydrophobic seams between alpha-helical chains. Residues that form these seams occur at the first (a) and fourth (d) positions of a characteristic 7-aa repeat and are primarily aliphatic. The pote...
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.0405319101
更新日期:2004-11-16 00:00:00
abstract::Neurodegenerative diseases and noxious stimuli to the brain enhance transcription of serum- and glucocorticoid-induced kinase-1 (SGK1). Here, we report that the SGK1 gene encodes a brain-specific additional isoform, SGK1.1, which exhibits distinct regulation, properties, and functional effects. SGK1.1 decreases expres...
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.0800958105
更新日期:2008-03-18 00:00:00
abstract::RNA synthesis by the paramyxovirus respiratory syncytial virus, a ubiquitous human pathogen, was found to be more complex than previously appreciated for the nonsegmented negative-strand RNA viruses. Intracellular RNA replication of a plasmid-encoded "minigenome" analog of viral genomic RNA was directed by coexpressio...
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.93.1.81
更新日期:1996-01-09 00:00:00
abstract::The rate of derepressed synthesis of a membrane protein required for lactose transport (M protein) by Escherichia coli is increased in response to increased gene dosage to the same extent as the rates of synthesis of beta-galactosidase and galactoside acetylase. However, elevated gene dosage does not increase beta-gal...
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.63.3.850
更新日期:1969-07-01 00:00:00
abstract::A sensitive test for kinetic unfolding intermediates in ribonuclease A (EC 3.1.27.5) is performed under conditions where the enzyme unfolds slowly (10 degrees C, pH 8.0, 4.5 M guanidinium chloride). Exchange of peptide NH protons (2H-1H) is used to monitor structural opening of individual hydrogen bonds during unfoldi...
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.92.7.2657
更新日期:1995-03-28 00:00:00
abstract::High molecular weight RNA (35S) isolated from avian myeloblastosis virus directs the cell-free synthesis of two prominent polypeptides of 180,000 and 76,000 molecular weight. The latter polypeptide has previously been identified as the precursor to the group-specific antigens of the virus ("gag" proteins) [Vogt, V. M....
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.74.11.4951
更新日期:1977-11-01 00:00:00
abstract::Explanations for biogeographic disjunctions involving South America and Africa typically invoke vicariance of western Gondwanan biotas or long distance dispersal. These hypotheses are problematical because many groups originated and diversified well after the last known connection between Africa and South America (app...
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.102175899
更新日期:2002-05-14 00:00:00
abstract::Speciation involves the origin of trait differences that limit or prevent gene exchange and ultimately results in daughter populations that form monophyletic or exclusive genetic groups. However, for recently diverged populations or species between which reproductive isolation is often incomplete, gene genealogies wil...
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.0502054102
更新日期:2005-10-11 00:00:00
abstract::Broken-cell preparations of Salmonella typhimurium rapidly incorporated 75Se from 75SeO3(2-) into tRNA by an ATP-dependent process. Selenium incorporation in the presence of 50 microM 75SeO3(2-) (0.8-1 pmol per A260 unit) was enhanced by the selenocysteine precursor, O-acetyl-L-serine (to 3.7 pmol per A260 unit). This...
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.87.16.6341
更新日期:1990-08-01 00:00:00
abstract::An ammonia-oxidizing, carbon-fixing archaeon, Candidatus "Nitrosopumilus maritimus," recently was isolated from a salt-water aquarium, definitively confirming that chemoautotrophy exists among the marine archaea. However, in other incubation studies, pelagic archaea also were capable of using organic carbon. It has re...
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.0510157103
更新日期:2006-04-25 00:00:00
abstract::We have cloned a murine cDNA encoding a tyrosine kinase receptor with about 90% similarity to the chicken fibroblast growth factor (FGF) receptor and the human fms-like gene (FLG) tyrosine kinase. This mouse receptor lacks 88 amino acids in the extracellular portion, leaving only two immunoglobulin-like domains compar...
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.87.11.4378
更新日期:1990-06-01 00:00:00
abstract::The epothilones represent a promising class of natural product-based antitumor drug candidates. Although these compounds operate through a microtubule stabilization mechanism similar to that of taxol, the epothilones offer a major potential therapeutic advantage in that they retain their activity against multidrug-res...
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.0804773105
更新日期:2008-09-02 00:00:00
abstract::These studies sought to determine if neurons in the estrogen receptor-alpha knockout (ERalphaKO) mouse brain concentrated 16alpha-[125I]iodo-11beta-methoxy-17beta-estradiol (125I-estrogen), and if so, whether estrogen binding augmented the expression of progesterone receptor (PR) mRNA. Mice were injected with 125I-est...
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.94.20.11008
更新日期:1997-09-30 00:00:00
abstract::We have found that poly(L-lysine) can be a very effective agent in preventing the growth of Ehrlich ascites tumors in mice. When given optimal doses of poly(L-lysine) (Mr 60 x 10(3)) intraperitoneally for 5 consecutive days, beginning on day 1 after inoculation with Ehrlich ascites cells. White Swiss mice show nearly ...
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.76.7.3246
更新日期:1979-07-01 00:00:00
abstract::Although peroxynitrite is harmful to the host, the beneficial effects of peroxynitrite are less well understood. We explored the role of peroxynitrite in the host immune response to Coxsackievirus infection. Peroxynitrite inhibits viral replication in vitro, in part by inhibiting viral RNA entry into the host cell. Ni...
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.0400518101
更新日期:2004-08-10 00:00:00
abstract::During clathrin-mediated endocytosis, adaptor proteins recognize specific internalization signals on cargo receptors, either recruiting cargos into clathrin-coated pits (CCPs) or initiating clathrin-coat assembly around the cargo molecules. Here, we identify epsin 1, a clathrin-, ubiquitin-, and phospholipid-interacti...
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.0803711105
更新日期:2008-08-19 00:00:00
abstract::Gene conversion and conversion-associated reciprocal recombination have been studied in various Saccharomyces cerevisiae hybrids. In a sample of 11,023 unselected meiotic tetrads, 907 conversions were observed at the arg4, thr3, his1, and SUP6 loci. Of these conversions, 445 (or 49.1%) were associated with reciprocal ...
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.69.1.101
更新日期:1972-01-01 00:00:00
abstract::A two-component transposon system based on the Ac element of maize was used as a mutagen in Arabidopsis thaliana. Transposition of a Ds element marked with a hygromycin-resistance gene was activated from four different locations in the Arabidopsis genome. The progeny of 201 plants carrying independent transposition ev...
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.90.21.10370
更新日期:1993-11-01 00:00:00
abstract::By using a mixture of synthetic oligodeoxyribonucleotides as a probe, cloned cDNA sequences specific for low molecular weight (LMW) kininogen have been isolated from a cDNA library of bovine liver mRNA sequences. Nucleotide sequence analyses of cloned cDNA inserts have revealed that bovine liver LMW kininogens are enc...
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.80.1.90
更新日期:1983-01-01 00:00:00
abstract::Mutations in fibroblast growth factor receptor 2 (FGFR2) and its ligand, FGF10, are known to cause lacrimo-auriculo-dento-digital (LADD) syndrome. Multiple gain-of-function mutations in FGF receptors have been implicated in a variety of severe skeletal disorders and in many cancers. We aimed to elucidate the mechanism...
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.0709905104
更新日期:2007-12-11 00:00:00
abstract::Here we study the effects of many-body interactions on rate and mechanism in protein folding by using the results of molecular dynamics simulations on numerous coarse-grained Calpha-model single-domain proteins. After adding three-body interactions explicitly as a perturbation to a Gō-like Hamiltonian with native pair...
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.0403486101
更新日期:2004-10-19 00:00:00
abstract::Here we describe a strategy designed to identify RNAs that are actively transported to synapses during learning. Our approach is based on the characterization of RNA transport complexes carried by molecular motor kinesin. Using this strategy in Aplysia, we have identified 5,657 unique sequences consisting of both codi...
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.1304422110
更新日期:2013-04-30 00:00:00
abstract::Individual cell types are defined by architecturally and functionally specialized cortical domains. The Ezrin, Radixin, and Moesin (ERM) proteins play a major role in organizing cortical domains by assembling membrane protein complexes and linking them to the cortical actin cytoskeleton. Many studies have focused on t...
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.1103418108
更新日期:2011-07-19 00:00:00
abstract::Climate change is increasing fire activity in the western United States, which has the potential to accelerate climate-induced shifts in vegetation communities. Wildfire can catalyze vegetation change by killing adult trees that could otherwise persist in climate conditions no longer suitable for seedling establishmen...
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.1815107116
更新日期:2019-03-26 00:00:00
abstract::Individual organisms are complex in a special way. The organization and function of their parts seem directed toward a purpose: the survival and reproduction of that individual. Groups of organisms are different. They may also be complex, but that is usually because their parts, the individual organisms, are working 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.0701285104
更新日期:2007-05-15 00:00:00
abstract::The size of an organism reflects its metabolic rate, growth rate, mortality, and other important characteristics; therefore, the distribution of body size is a major determinant of ecosystem structure and function. Body-size distributions often are multimodal, with several peaks of abundant sizes, and previous studies...
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.1211761110
更新日期:2013-01-02 00:00:00
abstract::TIM-4, a member of the TIM family expressed on antigen-presenting cells, binds to phosphatidylserine exposed on the surface of apoptotic bodies. However, the significance of this interaction in vivo remains unknown because other receptors have been implicated in the clearance of apoptotic bodies and could compensate 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.0910359107
更新日期:2010-05-11 00:00:00