Abstract:
:A complex of ribosomal DNA with RNA has been isolated from ovaries of metamorphosing tadpoles of Xenopus laevis. The complex is disrupted by treatments that destroy hydrogen bonds, and the sedimentation of the DNA within the complex is sensitive to RNase. We suggest that the RNA-ribosomal DNA complex is an intermediate in the synthesis of amplified ribosomal DNA and that the RNA is a template. In addition, in a preliminary attempt to mimic the amplification process in vitro, we have demonstrated the use of this RNA from the complex as a template for DNA synthesis by a DNA polymerase isolated from ovaries of Xenopus.
journal_name
Proc Natl Acad Sci U S Aauthors
Brown RD,Tocchini-Valentini GPdoi
10.1073/pnas.69.7.1746subject
Has Abstractpub_date
1972-07-01 00:00:00pages
1746-8issue
7eissn
0027-8424issn
1091-6490journal_volume
69pub_type
杂志文章abstract::Some pathogenesis-related genes are expressed in fungi only when the pathogen is in the host, but the host signals that trigger these gene expressions have not been identified. Virulent Nectria haematococca infects pea plants and requires either pelA, which is induced by pectin, or pelD, which is induced only in plant...
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.0500312102
更新日期:2005-03-15 00:00:00
abstract::Old noninbred fly mortality decreases according to the inverse linear law and reduces to a single suborder-specific age. Relative child mortality (the mortality at a given age related to the mortality at 10 years) from 1 mo to 11 years is the same with 8% mean accuracy for all humans, independent of race, country, sex...
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.95.15.9037
更新日期:1998-07-21 00:00:00
abstract::The single-pass transmembrane domains (TMDs) of the syndecan family of cell surface adhesion molecules have been implicated in functional protein-protein interactions. Although each paralog contains a conserved GxxxG dimerization motif, we show here that the syndecan-1 TMD dimerizes weakly, the syndecan-3 and syndecan...
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.0708909105
更新日期:2007-12-26 00:00:00
abstract::The F(1)F(0) ATP synthase is the smallest motor enzyme known. Previous studies had established that the central stalk, made of the gamma and epsilon subunits in the F(1) part and c subunit ring in the F(0) part, rotates relative to a stator composed of alpha(3)beta(3)deltaab(2) during ATP hydrolysis and synthesis. How...
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.111128098
更新日期:2001-06-05 00:00:00
abstract::Brain-derived neurotrophic factor (BDNF), a cognate ligand for the tyrosine kinase receptor B (TrkB) receptor, mediates neuronal survival, differentiation, synaptic plasticity, and neurogenesis. However, BDNF has a poor pharmacokinetic profile that limits its therapeutic potential. Here we report the identification of...
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.0913572107
更新日期:2010-02-09 00:00:00
abstract::Pleistocene residential sites with multiple contemporaneous human burials are extremely rare in the Americas. We report mitochondrial genomic variation in the first multiple mitochondrial genomes from a single prehistoric population: two infant burials (USR1 and USR2) from a common interment at the Upward Sun River Si...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.1511903112
更新日期:2015-11-10 00:00:00
abstract::Considerable effort has been directed toward controlling tuberculosis, which kills almost two million people yearly. High on the research agenda is the discovery of biomarkers of active tuberculosis (TB) for diagnosis and for monitoring treatment outcome. Rational biomarker discovery requires understanding host-pathog...
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.1009080107
更新日期:2010-08-17 00:00:00
abstract::A vitamin D(3) metabolite in intestine more polar than 25-hydroxy-vitamin D(3)(25-OH D(3)) has been detected by countercurrent distribution. The intestinal metabolite is found also after administration of labeled hydroxy D(3), indicating that it arises from vitamin D(3) via the intermediate 25-hydroxy derivative. 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.68.1.177
更新日期:1971-01-01 00:00:00
abstract::CCR5 (R5)-tropic, but not CXCR4 (X4)-tropic, HIV-1 is associated with primary HIV-1 infection and transmission. Recent studies have shown that IFN-induced transmembrane (IFITM) proteins, including IFITM1, IFITM2, and IFITM3, restrict a broad range of viruses. Here, we demonstrate that an IFITM2 isoform (Δ20 IFITM2) la...
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.1619640114
更新日期:2017-07-03 00:00:00
abstract::An improved electron cloud bolometer is analyzed. In this device the cloud temperature is read out not via thermal noise induced by the electrons in a coupled LC circuit but via shift in their axial oscillation frequency in the Penning trap confining them. This shift occurs because as the electron cloud expands with 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.91.14.6308
更新日期:1994-07-05 00:00:00
abstract::Recent advances in coherent x-ray diffractive imaging have paved the way to reliable and quantitative imaging of noncompact specimens at the nanometer scale. Introduced a year ago, an advanced implementation of ptychographic coherent diffractive imaging has removed much of the previous limitations regarding sample pre...
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.0905846107
更新日期:2010-01-12 00:00:00
abstract::Insight regarding how diverse enzymatic functions and reactions have evolved from ancestral scaffolds is fundamental to understanding chemical and evolutionary biology, and for the exploitation of enzymes for biotechnology. We undertook an extensive computational analysis using a unique and comprehensive combination o...
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.1706849114
更新日期:2017-11-07 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::We propose a conceptual model for the cytoskeletal organization of endothelial cells (ECs) based on a major dichotomy in structure and function at basal and apical aspects of the cells. Intracellular distributions of filamentous actin (F-actin), vinculin, paxillin, ZO-1, and Cx43 were analyzed from confocal micrograph...
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.0407474101
更新日期:2004-11-23 00:00:00
abstract::The tissue-specific expression of the chicken liver cell adhesion molecule (L-CAM) was studied by generating transgenic mice. The rat insulin II promoter was fused to a chicken L-CAM cDNA or to chicken genomic L-CAM sequences. Mice carrying the cDNA showed no expression of L-CAM. Mice carrying L-CAM genomic sequences ...
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.87.22.9042
更新日期:1990-11-01 00:00:00
abstract::Although adaptor ADAP (FYB) and its binding to SLP-76 has been implicated in TcR-induced "inside-out" signaling for LFA-1 activation in T cells, little is known regarding its role in LFA-1-mediated "outside-in" signaling. In this study, we demonstrate that ADAP and SLP-76-ADAP binding are coupled to LFA-1 costimulatio...
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.0900510106
更新日期:2009-07-28 00:00:00
abstract::The question of what is a perceptual object is one of the most central and also controversial issues in cognitive science. According to the topological approach to perceptual organization, the core intuitive notion of an object--the holistic identity preserved over shape-changing transformations--may be characterized ...
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.1010919108
更新日期:2010-12-14 00:00:00
abstract::Type I (IFN-alpha/beta) and type III (IFN-lambdas) IFNs are important components of the host antiviral response. Although type III IFNs possess intrinsic antiviral activity similar to that of type I IFNs, they signal through a specific unique receptor complex, and their functional importance for antiviral resistance 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.0610352104
更新日期:2007-06-05 00:00:00
abstract::2-Isopropylmalate synthase (EC 4.1.3.12) of yeast is a mitochondrial enzyme. We now provide evidence showing that a large part of the 2-isopropylmalate synthase activity that is associated with the mitochondria is located in the mitochondrial matrix. In vitro translation of total yeast RNA followed by immunoprecipitat...
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.80.5.1270
更新日期:1983-03-01 00:00:00
abstract::TGF-beta-activated kinase-1 (TAK1), also known as MAPKK kinase-7 (MAP3K7), is a candidate effector of multiple circuits in cardiac biology and disease. Here, we show that inhibition of TAK1 in mice by a cardiac-specific dominant-negative mutation evokes electrophysiological and biochemical properties reminiscent of hu...
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.0604708103
更新日期:2006-11-14 00:00:00
abstract::The recent development of HIV-1 lentiviral vectors is especially useful for gene transfer because they achieve efficient integration into nondividing cell genomes and successful long-term expression of the transgene. These attributes make the vector useful for gene delivery, mutagenesis, and other applications in mamm...
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.062032499
更新日期:2002-03-19 00:00:00
abstract::The exopolysaccharide alginate is a major virulence factor in the pathogenicity of Pseudomonas aeruginosa infecting the lungs of cystic fibrosis (CF) patients. Alginate synthesis by P. aeruginosa is believed to occur in response to environmental signals present in the CF lung. Transcription of a critical alginate bios...
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.89.7.2659
更新日期:1992-04-01 00:00:00
abstract::The nucleus accumbens (NAc) serves as a key neural substrate that controls acute and adaptive behavioral responses to cocaine administration. In this circuit, inputs from the NAc are transmitted through two parallel pathways, named the direct and indirect pathways, and converge at the substantia nigra pars reticulata ...
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.1107592108
更新日期:2011-06-14 00:00:00
abstract::We recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 88 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results sugg...
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.85.1.193
更新日期:1988-01-01 00:00:00
abstract::The cytoplasm and biomembranes in biological cells contain large numbers of proteins that cyclically change their shapes. They are molecular machines that can function as molecular motors or carry out various other tasks in the cell. Many enzymes also undergo conformational changes within their turnover cycles. We ana...
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.1506825112
更新日期:2015-07-14 00:00:00
abstract::Spontaneous reciprocal mitotic recombination in the yeast Saccharomyces cerevisiae, associated with heteroallelic recombination, occurs almost exclusively at the two-strand stage and involves recombination of unduplicated chromosomes (i.e., during G1) or the unduplicated regions of chromosomes during the S phase of mi...
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.75.9.4436
更新日期:1978-09-01 00:00:00
abstract::Acute myeloid leukemia subtype M4 with eosinophilia is associated with a chromosome 16 inversion that creates a fusion gene CBFB-MYH11. We have previously shown that CBFB-MYH11 is necessary but not sufficient for leukemogenesis. Here, we report the identification of genes that specifically cooperate with CBFB-MYH11 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.0400930101
更新日期:2004-04-06 00:00:00
abstract::The dendritic building blocks with a focal pyrene unit self-organize into vesicles in aqueous phase. The in situ inclusion of the focal pyrene units into the cavity of beta- or gamma-cyclodextrin (CD) induces self-assembled organic nanotubes with an average outer diameter of approximately 45 nm and inner diameter of 2...
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.0505364103
更新日期:2006-01-31 00:00:00
abstract::The effect of carlorie intake on the development of spontaneous mammary tumors in virgin C3H mice was studied. Only about 10% of the mice fed a low-calorie diet [10 kcal/day (1 kcal = 4.184 kJ)] since weaning developed mammary tumors, compared to about 60% of those mice that were reared on high-calorie diets (16 kcal/...
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.79.24.7758
更新日期:1982-12-01 00:00:00
abstract::Human sporadic Creutzfeldt-Jakob disease (sCJD), endemic sheep scrapie, and epidemic bovine spongiform encephalopathy (BSE) are caused by a related group of infectious agents. The new U.K. BSE agent spread to many species, including humans, and clarifying the origin, specificity, virulence, and diversity of these agen...
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.0905825106
更新日期:2009-08-11 00:00:00