Abstract:
:Cloned 3.18 kilobase fragments of Xenopus laevis DNA containing genes for tRNAMet1 and for at least one other 4S RNA species are transcribed rapidly after their injection into the nucleus of X. laevis oocytes. The newly synthesized RNA can be resolved by gel electrophoresis into a few predominant 4S RNA species and a series of slower migrating components. One of the 4S RNA species appears to be identical, by fingerprint analysis, to the tRNAMet1 isolated by hybridization of somatic cell RNA to this cloned tRNA gene fragment (tDNA). Thus, the tRNAMet1 produced after injection can be both fully processed and modified. Its rate of synthesis is estimated to be about 6 x 10(9) molecules/hr in each oocyte injected with 2 ng of tDNA. When the tDNA fragment is cleaved into two halves with restriction endonuclease Sst I, each injected half gives rise to a subset of the RNAs produced after injection of the intact fragment. This experiment thus suggests the presence of at least two transcriptional units on this cloned tDNA. This simple way of biologically testing defined restriction fragments may be of value for analyzing the functional organization of other cloned eukaryotic DNA units.
journal_name
Proc Natl Acad Sci U S Aauthors
Kressmann A,Clarkson SG,Pirrotta V,Birnstiel MLdoi
10.1073/pnas.75.3.1176subject
Has Abstractpub_date
1978-03-01 00:00:00pages
1176-80issue
3eissn
0027-8424issn
1091-6490journal_volume
75pub_type
杂志文章abstract::Evidence is presented that suggests that GTP (or 5'-guanylylmethylene diphosphonate) is not essential for either formation of an AUG-directed, initiation factor IF-2-dependent initiation complex on the 30S subunit or for positioning of fMet-tRNA on the peptidyl site. However, recycling of limiting amounts of IF-2 requ...
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.69.10.2770
更新日期:1972-10-01 00:00:00
abstract::Myosins are molecular motors that power diverse cellular processes, such as rapid organelle transport, muscle contraction, and tension-sensitive anchoring. The structural adaptations in the motor that allow for this functional diversity are not known, due, in part, to the lack of high-resolution structures of highly 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.1321022111
更新日期:2014-02-11 00:00:00
abstract::Seven morphologically nontransformed (flat) revertants with reduced tumorigenicity in vivo have been isolated from populations of Kirsten sarcoma virus-transformed NIH 3T3 cells transfected with a cDNA expression library of normal human fibroblasts. Each revertant harbors 1-10 recombinant plasmids per cell and retains...
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.86.1.162
更新日期:1989-01-01 00:00:00
abstract::The genome of a thermophilic fungus, Thermomyces lanuginosus, contains a tandemly arranged cluster of sequences that are approximately equal to 50% homologous with the cytoplasmic 5S RNA and that are selectable by hybridization techniques. Unlike typical pseudogenes, these sequences are not truncated; rather, they bea...
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.81.6.1768
更新日期:1984-03-01 00:00:00
abstract::E-Cadherin, a cell adhesion molecule, which plays a key role in maintaining the epithelial phenotype, is regarded as an invasion-suppressor gene in light of accumulating evidence from in vitro experiments and clinical observations. In an attempt to clarify the mechanism responsible for inactivation of this gene in car...
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.92.16.7416
更新日期:1995-08-01 00:00:00
abstract::An inversion loop seen in heteroduplex mapping of the DNA of mature Mu phage induced from a lysogen is observed also in defective lambda phage carrying one end of Mu. 14% of the DNA of Mu, including this region, designated the G loop, is shown to be to the right of all known genes in the prophage map. The inhomogeneou...
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.70.7.2153
更新日期:1973-07-01 00:00:00
abstract::Inhibitory gamma-aminobutyric acid-mediated synaptic currents were studied in dissociated primary cultures of neonatal rat cortex with the whole-cell patch-clamp technique. Immunocytochemical staining of the cultures showed the presence of a large number of glutamic acid decarboxylase-containing neurons, and electrica...
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.83.23.9269
更新日期:1986-12-01 00:00:00
abstract::3S(-)-N-(2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1,4- benzodiazepine-3-yl)-1H-indole-2-carboxamide (L-364,718) interacted in a competitive manner with rat pancreatic cholecystokinin (CCK) receptors as determined by Scatchard analysis of the specific binding of 125I-labeled CCK. The affinity of L-364,718 for both pancre...
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.83.13.4923
更新日期:1986-07-01 00:00:00
abstract::The best-studied cytoskeletal system is the inner surface of the erythrocyte membrane, which provides an erythrocyte with the structural support needed to be stable yet flexible as it passes through the circulation. Current structural models predict that the spectrin-actin-based cytoskeletal network is attached to 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.0706266104
更新日期:2007-08-28 00:00:00
abstract::Mounting effective T cell responses is critical for eliciting long-lasting immunity following viral infection and vaccination. A multitude of inhibitory and stimulatory factors are induced following infection, and it is the compilation of these signals that quantitatively and qualitatively program the ensuing effector...
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.0914500107
更新日期:2010-02-16 00:00:00
abstract::The biological roles of estrogen-responsive finger protein (efp) in vivo were evaluated in mice carrying a loss-of-function mutation in efp by gene-targeted mutagenesis. Although efp homozygous mice were viable and fertile in both sexes, the uterus that expressed abundant estrogen receptor alpha exhibited significant ...
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.96.21.12027
更新日期:1999-10-12 00:00:00
abstract::The heterodimeric Elongin BC complex has been shown to interact in vitro and in cells with a conserved BC-box motif found in an increasing number of proteins including RNA polymerase II elongation factor Elongin A, suppressor of cytokine signaling (SOCS)-box proteins, and the von Hippel-Lindau tumor suppressor protein...
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.162424199
更新日期:2002-08-06 00:00:00
abstract::In 1989, populations of North American gypsy moth, Lymantria dispar, in seven contiguous northeastern states were severely reduced by a fungal pathogen. Based on morphology, development, and pathology, this organism appeared to be Entomophaga maimaiga. We have now used allozyme and restriction fragment length polymorp...
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.87.18.6979
更新日期:1990-09-01 00:00:00
abstract::Resistance to ionizing radiation (IR), which is a conventional treatment for osteosarcoma that cannot be resected, undermines the efficacy of this therapy. However, the mechanism by which IR induces radioresistance in osteosarcoma is not defined. Here, we report that CR6-interacting factor-1 (CRIF1) is highly expresse...
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.1906578116
更新日期:2019-10-08 00:00:00
abstract::Recent advances in high-field MRI have dramatically improved the visualization of human brain anatomy in vivo. Most notably, in cortical gray matter, strong contrast variations have been observed that appear to reflect the local laminar architecture. This contrast has been attributed to subtle variations in the magnet...
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.0911177107
更新日期:2010-02-23 00:00:00
abstract::The human epidermal growth factor receptor 2 (HER2) is specifically overexpressed in tumors of several cancers, including an aggressive form of breast cancer. It is therefore a target for both cancer diagnostics and therapy. The 58 amino acid residue Zher2 affibody molecule was previously engineered as a high-affinity...
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.1005025107
更新日期:2010-08-24 00:00:00
abstract::Evidence for hydrogen bonding between 5'-ribonucleotides in water has been obtained from a 220-MHz proton magnetic resonance study of nitrogenous protons. The amino groups of GMP, AMP, and CMP exhibit proton resonance lines which are somewhat broadened by proton exchange with the solvent at 0 degrees ; their downfield...
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.69.8.2025
更新日期:1972-08-01 00:00:00
abstract::The functional capacities of CD8(+) T cells important for virus clearance are influenced by interactions with antigen presenting cells (APCs) and CD4(+) T cells during initial selection, subsequent expansion, and development of memory. Recently, investigators have shown that polyfunctional T cells correlate best with ...
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.0915168107
更新日期:2010-02-23 00:00:00
abstract::Some strains of Bradyrhizobium japonicum produce rhizobitoxine, a phytotoxin that causes foliar chlorosis on susceptible host plants. We have previously obtained Tn5-induced rhizobitoxine null mutants of B. japonicum. DNA sequence analysis of the region surrounding two Tn5 insertions identifies two overlapping open 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.90.7.2641
更新日期:1993-04-01 00:00:00
abstract::The maspin protein has tumor suppressor activity in breast and prostate cancers. It inhibits cell motility and invasion in vitro and tumor growth and metastasis in nude mice. Maspin is structurally a member of the serpin (serine protease inhibitors) superfamily but deviates somewhat from classical serpins. We find tha...
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.95.2.499
更新日期:1998-01-20 00:00:00
abstract::Sequence-specific gene silencing by short hairpin (sh) RNAs has recently emerged as an indispensable tool for understanding gene function and a promising avenue for drug discovery. However, a wider biomedical use of this approach is hindered by the lack of straightforward methods for achieving uniform expression of 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.1103532108
更新日期:2011-08-02 00:00:00
abstract::Although it is known that the c-myc oncogene is rearranged in a head-to-head fashion with the immunoglobulin heavy chain locus in mouse plasmacytomas, it has not been clear whether the c-myc oncogene is translocated to the heavy chain locus on mouse chromosome 12 or whether the heavy chain locus is translocated to 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.82.12.4212
更新日期:1985-06-01 00:00:00
abstract::A structural gene for the alpha-subunit of RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) has been identified and mapped between spcA and trkA, near 64 min on the E. coli chromosome. It appears to be coordinately expressed and possibly cotranscribed with the genes for ribosomal proteins...
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.72.12.5036
更新日期:1975-12-01 00:00:00
abstract::Neutrinos represent a new "window" to the Universe, spanning a large range of energy. We discuss the science of neutrino astrophysics and focus on two energy regimes. At "lower" energies ( approximately 1 MeV), studies of neutrinos born inside the sun, or produced in interactions of cosmic rays with the atmosphere, ha...
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.96.25.14201
更新日期:1999-12-07 00:00:00
abstract::The mechanism of Ca2+-dependent protein-protein interaction and enzyme activation by calmodulin was investigated with the phosphoprotein phosphatase, calcineurin. Dimethylaminonaphthalene (dansyl)-calmodulin, a fluorescent derivative used to monitor complex formation, produced similar maximal activation (10- to 12-fol...
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.83.5.1193
更新日期:1986-03-01 00:00:00
abstract::A clone for the iron-responsive element (IRE)-binding protein (IRE-BP) has been transfected and expressed in mouse fibroblasts. The IRE-BP gene product binds IREs with high affinity and specificity. Amino acid alignments reveal that the IRE-BP is 30% identical to mitochondrial aconitase. The 18 active site residues 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.88.22.10109
更新日期:1991-11-15 00:00:00
abstract::The rates of reassociation of DNA from a monkey cell line (Vero), from SV40 pseudovirus (consisting of Vero DNA and virus protein coat), and from mature SV40 were measured. The results show that the host DNA in the pseudovirus contains repeated and unique sequences in the same proportions as normal host DNA; hence, no...
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.67.4.1886
更新日期:1970-12-01 00:00:00
abstract::Recombinant human migration inhibitory factor (MIF), isolated through functional expression cloning in COS-1 cells, up-regulates expression of genes encoding HLA-DR and interleukin 1 beta (IL-1 beta) and elaboration of IL-1 beta by human monocyte-derived macrophages. Administration of soluble bovine serum albumin or h...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,收录出版
doi:10.1073/pnas.89.17.8049
更新日期:1992-09-01 00:00:00
abstract::The role of the mouse tumor necrosis factor (TNF) promoter, 5' untranslated region (UTR), and 3' UTR in TNF gene expression has been examined in three nonmacrophage cell lines (HeLa, NIH 3T3, and L-929). The TNF promoter is not macrophage-specific. On the contrary, it constitutively drives reporter gene expression 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.89.2.673
更新日期:1992-01-15 00:00:00
abstract::A major part of the present understanding of the molecular basis of signal transduction has been gained from in vitro studies using classical biochemical methods. In this study, we used 31P NMR spectroscopy to investigate the response of live M2R mouse melanoma cells to stimulation by melanocyte-stimulating hormone (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.88.4.1506
更新日期:1991-02-15 00:00:00