Abstract:
:Three classes of heterogeneous nuclear RNA (HnRNA) alpha, beta, and gamma, with different chemical and physical properties, can be identified in the early sea urchin embryo by hybridization with poly(U). The relative amounts of these classes vary as a function of embryonic development. It is demonstrated here that the adenyl-containing classes of HnRNA, alpha and beta, can be subfractionated by hybridization with poly(A)-agarose into species containing and lacking oligo(U)-enriched segments. These oligo(U) segments could not be detected in gamma HnRNA, which was previously shown to also lack adenylate segments. The relative proportions of these species undergo marked changes during development from early blastula (7 hr) to mesenchyme blastula (20 hr). I propose models to explain the possible effects of complementary sequences of adenylate and uridylate on the secondary structure of HnRNA, and speculate on the functional significance of such complexes.
journal_name
Proc Natl Acad Sci U S Aauthors
Dubroff LMdoi
10.1073/pnas.74.6.2217subject
Has Abstractpub_date
1977-06-01 00:00:00pages
2217-21issue
6eissn
0027-8424issn
1091-6490journal_volume
74pub_type
杂志文章abstract::Changes in O-linked protein glycosylation are known to correlate with disease states but are difficult to monitor in a physiological setting because of a lack of experimental tools. Here, we report a technique for rapid profiling of O-linked glycoproteins in living animals by metabolic labeling with N-azidoacetylgalac...
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.0506855103
更新日期:2006-03-28 00:00:00
abstract::DNA delivery of IL-12 has shown promise in reducing the toxic side effects associated with administration of recombinant human (h)IL-12 protein while maintaining the ability to inhibit tumor growth and abolish tumor metastases in animal models. We have developed a more potent version of IL-12 by using DNA shuffling an...
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.0237327100
更新日期:2003-02-04 00:00:00
abstract::The human beta-globin locus control region (LCR) consists of four erythroid-specific DNaseI hypersensitive sites (HSs) at the 5' end of the beta-globin cluster. The LCR functions over a long distance on chromosome 11 to regulate transcription and replication of the beta-globin genes. To determine whether the HSs funct...
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.94.9.4566
更新日期:1997-04-29 00:00:00
abstract::Two approaches have been explored for the synthesis of double-stranded DNA from single-stranded DNA template complementary to rabbit 9S globin mRNA (cDNA). (i) cDNA was elongated with dCMP or dTMP homopolymeric tracts using terminal deoxynucleotidyltransferase (EC 2.7.7.31; nucleosidetriphosphate:DNA deoxynucleotidyle...
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.73.10.3418
更新日期:1976-10-01 00:00:00
abstract::Gamma-band synchronization adjusts the timing of excitatory and inhibitory inputs to a neuron. Neurons in the visual cortex are selective for stimulus orientation because of dynamic interactions between excitatory and inhibitory inputs. We hypothesized that these interactions and hence also orientation selectivity var...
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.1114223109
更新日期:2012-03-13 00:00:00
abstract::Mate attraction in Aplysia involves a long-distance water-borne signal (the protein pheromone attractin), which is released during egg laying. Aplysia californica attractin attracts species that produce closely related attractins, such as Aplysia brasiliana, whose geographic distribution does not overlap that of A. ca...
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.0306339101
更新日期:2004-05-04 00:00:00
abstract::Mitogen-activated protein (MAP) kinase kinase is an enzyme that activates the growth factor-regulated MAP kinase in vitro by a mechanism that involves direct phosphorylation of MAP kinase on tyrosine and threonine residues. MAP kinase kinase is stimulated by growth factor treatment of cells and has been shown to be 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.90.11.5143
更新日期:1993-06-01 00:00:00
abstract::Tumor hypoxia reduces the effectiveness of radiation therapy by limiting the biologically effective dose. An acute increase in tumor oxygenation before radiation treatment should therefore significantly improve the tumor cell kill after radiation. Efforts to increase oxygen delivery to the tumor have not shown positiv...
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.1808945115
更新日期:2018-10-16 00:00:00
abstract::Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in...
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.1112839109
更新日期:2012-02-28 00:00:00
abstract::Ascidians are hermaphrodites releasing sperm and eggs simultaneously, but many species are self-sterile because of a self/nonself-recognition system in spermegg interaction. Here, we show that a 70-kDa vitelline coat protein, HrVC70, consisting of 12 epidermal growth factor-like repeats, plays a key role in self/nonse...
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.0401928101
更新日期:2004-11-02 00:00:00
abstract::2fTGH is a human cell line containing the selectable marker guanine phosphoribosyltransferase regulated by alpha interferon (IFN-alpha). Two IFN-alpha-unresponsive mutants were isolated previously at a low frequency (ca. 10(-8)) by selecting mutagenized 2fTGH cells in selective medium containing 6-thioguanine and IFN-...
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.88.24.11455
更新日期:1991-12-15 00:00:00
abstract::Two-electron oxidation of cobaltous octaethylporphyrin [Co(II)(Et)(8)P] yields a stable pi-cation radical [Co(III)(Et)(8)P](2+.), the optical spectrum of which exhibits spectral changes dependent upon the nature of the counterion. Comparison of these spectra with those of Compounds I of horseradish peroxidase and cata...
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.68.3.614
更新日期:1971-03-01 00:00:00
abstract::All immunoglobulins and T-cell receptors throughout phylogeny share regions of highly conserved amino acid sequence. To identify possible primitive immunoglobulins and immunoglobulin-like molecules, we utilized 3' RACE (rapid amplification of cDNA ends) and a highly conserved constant region consensus amino acid seque...
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.93.8.3289
更新日期:1996-04-16 00:00:00
abstract::The total sequence of 365 amino acid residues in bovine prochymosin is presented. Alignment with the amino acid sequence of porcine pepsinogen shows that 204 amino acid residues are common to the two zymogens. Further comparison and alignment with the amino acid sequence of penicillopepsin shows that 66 residues are l...
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.74.6.2321
更新日期:1977-06-01 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::Chemoresistance of cisplatin therapy is related to extensive repair of cisplatin-modified DNA in the nucleus by the nucleotide excision repair (NER). Delivering cisplatin to the mitochondria to attack mitochondrial genome lacking NER machinery can lead to a rationally designed therapy for metastatic, chemoresistant ca...
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.1405244111
更新日期:2014-07-22 00:00:00
abstract::Chemical coding in the sympathetic nervous system involves both noradrenergic and, for a minority of neurons, cholinergic neurotransmission. The expression of the cholinergic phenotype in the developing sympathetic nervous system was examined to determine if coding for cholinergic transmission occurs before or after 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.94.8.4149
更新日期:1997-04-15 00:00:00
abstract::The ribosome is one of the major targets for therapeutic antibiotics; however, the rise in multidrug resistance is a growing threat to the utility of our current arsenal. The orthosomycin antibiotics evernimicin (EVN) and avilamycin (AVI) target the ribosome and do not display cross-resistance with any other classes 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.1604790113
更新日期:2016-07-05 00:00:00
abstract::The human renin gene was isolated from a Charon 4A human genomic library and characterized. The gene spans about 11.7 kilobases and consists of 10 exons and 9 introns that map at points that could be variable surface loops of the enzyme. The complete coding regions, the 5'- and 3'-flanking regions, and the exon-intron...
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.81.19.5999
更新日期:1984-10-01 00:00:00
abstract::The aspartate receptor involved in chemotaxis is modified by methyl esterification at four distinct glutamate residues during the adaptive response of this receptor. To explain the high degree of specificity of this modification, it has been proposed that the methyltransferase recognizes the sequence Glu-Glu-Xaa-Xaa-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.83.18.6707
更新日期:1986-09-01 00:00:00
abstract::Ca2+ ions control the cGMP-gated channel of rod photoreceptor cells from the external and internal face. We studied ion selectivity and blockage by Ca2+ of wild-type and mutant channels in a heterologous expression system. External Ca2+ blocks the inward current at micromolar concentrations in a highly voltage-depende...
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.91.3.1109
更新日期:1994-02-01 00:00:00
abstract::The apparent failure of infants to understand "object permanence" by reaching for hidden objects is perhaps the most striking and debated phenomenon in cognitive development. Of particular interest is the extent to which infants perceive and remember objects in a similar way to that of adults. Here we report two findi...
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.0507626102
更新日期:2005-10-18 00:00:00
abstract::A recently described experimental system for analyzing the mode of action of a morphogen gradient involves the in situ hybridization of sectioned tissue constructs. In these constructs, a source of activin signaling induces the transcription of several mesodermal genes in blastula animal caps, according to the positio...
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.93.18.9334
更新日期:1996-09-03 00:00:00
abstract::Data are presented that demonstrate that a dose of 10 R of x-rays to mature oocytes in Drosophila causes a significant increase, more than double the spontaneous frequency, of inherited translocations. The dose-frequency relationship appears to fit best a linear response between 10 and 50 R. From 50 to 500 R, the freq...
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.68.6.1095
更新日期:1971-06-01 00:00:00
abstract::Bovine pyruvate dehydrogenase phosphatase (PDP) is a Mg2+-dependent and Ca2+-stimulated heterodimer that is a member of the protein phosphatase 2C family and is localized to mitochondria. Insight into the function of the regulatory subunit of PDP (PDPr) has been gained. It decreases the sensitivity of the catalytic su...
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.93.10.4953
更新日期:1996-05-14 00:00:00
abstract::Studies on the structure-function relationship of diphtheria toxin are reported. New methods are described for the preparation of pure intact ("unnicked") toxin and for the preparation of the individual A and B chains. A biological assay method for the B chain is also presented, as well as a method for the labelling 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.74.2.472
更新日期:1977-02-01 00:00:00
abstract::The development of a spider silk-manufacturing process is of great interest. However, there are serious problems with natural manufacturing through spider farming, and standard recombinant protein production platforms have provided limited progress due to their inability to assemble spider silk proteins into fibers. 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.1109420109
更新日期:2012-01-17 00:00:00
abstract::The synthesis of graphene materials is typically carried out by oxidizing graphite to graphite oxide followed by a reduction process. Numerous methods exist for both the oxidation and reduction steps, which causes unpredictable contamination from metallic impurities into the final material. These impurities are known ...
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.1413389111
更新日期:2014-09-23 00:00:00
abstract::DNA polymerases replicate DNA by adding nucleotides to a growing primer strand while avoiding frameshift and point mutations. Here we present a series of up to six successive replication events that were obtained by extension of a primed template directly in a crystal of the thermostable Bacillus DNA polymerase I. 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.0630532100
更新日期:2003-04-01 00:00:00
abstract::Food choices are shifting globally in ways that are negatively affecting both human health and the environment. Here we consider how consuming an additional serving per day of each of 15 foods is associated with 5 health outcomes in adults and 5 aspects of agriculturally driven environmental degradation. We find that ...
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.1906908116
更新日期:2019-11-12 00:00:00