Abstract：
:When treated with heat-killed bacterial cells, mosquito cells in culture respond by up-regulating several proteins. Among these is a 66-kDa protein (p66) that is secreted from cells derived from both Aedes aegypti and Aedes albopictus. p66 was degraded by proteolysis and gave a virtually identical pattern of peptide products for each mosquito species. The sequence of one peptide (31 amino acids) was determined and found to have similarity to insect transferrins. By using conserved regions of insect transferrin sequences, degenerate oligonucleotide PCR primers were designed and used to isolate a cDNA clone encoding an A. aegypti transferrin. The encoded protein contained a signal sequence that, when cleaved, would yield a mature protein of 68 kDa. It contained the 31-amino acid peptide, and the 3' end exactly matched a cDNA encoding a polypeptide that is up-regulated when A. aegypti encapsulates filarial worms [Beerntsen, B. T., Severson, D. W. & Christensen, B. M. (1994) Exp. Parasitol. 79, 312-321]. This transferrin, like those of two other insect species, has conserved iron-binding residues in the N-terminal lobe but not in the C-terminal lobe, which also has large deletions in the polypeptide chain, compared with transferrins with functional C-terminal lobes. The hypothesis is developed that this transferrin plays a role similar to vertebrate lactoferrin in sequestering iron from invading organisms and that degradation of the structure of the C-terminal lobe might be a mechanism for evading pathogens that elaborate transferrin receptors to tap sequestered iron.
journal_name
Proc Natl Acad Sci U S Aauthors
Yoshiga T,Hernandez VP,Fallon AM,Law JHdoi
10.1073/pnas.94.23.12337subject
Has Abstractpub_date
1997-11-11 00:00:00pages
12337-42issue
23eissn
0027-8424issn
1091-6490journal_volume
94pub_type
杂志文章abstract：:The human immunodeficiency virus 1 (HIV-1) long terminal repeat (LTR) sequences were inserted into adenovirus in place of the E1 region. The HIV-1 LTR contained in this recombinant adenovirus responds to trans-activation by tatIII in a HeLa cell line constitutively expressing that HIV-1 gene product. In addition, 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.85.12.4200
更新日期：1988-06-01 00:00:00
abstract：:Interleukin 2 (IL-2) occupies a central position in the cascade of events involved in the immune response. We were interested in determining whether IL-2 could function as an adjuvant to vaccination, to increase the immune response to vaccine immunogens. Using the National Institutes of Health test for rabies vaccine ...
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.86.11.4240
更新日期：1989-06-01 00:00:00
abstract：:The great mass extinctions of the fossil record were a major creative force that provided entirely new kinds of opportunities for the subsequent explosive evolution and diversification of surviving clades. Today, the synergistic effects of human impacts are laying the groundwork for a comparably great Anthropocene mas...
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.0802812105
更新日期：2008-08-12 00:00:00
abstract：:For over a century neuroscientists have debated the dynamics by which human cortical language networks allow words to be spoken. Although it is widely accepted that Broca's area in the left inferior frontal gyrus plays an important role in this process, it was not possible, until recently, to detail the timing of its ...
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.1414491112
更新日期：2015-03-03 00:00:00
abstract：:IL-17 is a T cell-derived, proinflammatory cytokine that is suspected to be involved in the development of various inflammatory diseases. Although there are elevated levels of IL-17 in synovial fluid of patients with rheumatoid arthritis, the pathogenic role of IL-17 in the development of rheumatoid arthritis remains ...
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.1035999100
更新日期：2003-05-13 00:00:00
abstract：:Mutator activity associated with the common male recombination (MR) chromosomes in Drosophila melanogaster appears to be suppressed in natural populations. Crosses between geographically separated populations, however, lead to the release of mutator activity as measured by a significant increase in visible mutations. ...
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.77.2.1059
更新日期：1980-02-01 00:00:00
abstract：:P-glycoprotein is an ATP-binding cassette multidrug transporter that actively transports chemically diverse substrates across the lipid bilayer. The precise molecular mechanism underlying transport is not fully understood. Here, we present crystal structures of a eukaryotic P-glycoprotein homolog, CmABCB1 from Cyanidi...
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.1321562111
更新日期：2014-03-18 00:00:00
abstract：:Isolated human erythrocyte spectrin is a dimer of two unique polypeptide chains. The dimer (alpha beta) undergoes reversible salt- and temperature-dependent association to form (alpha beta)2 tetramers. Spectrin also binds with high affinity to a protein receptor on the cytoplasmic surface of erythrocyte membrane vesic...
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.77.11.6592
更新日期：1980-11-01 00:00:00
abstract：:P2X receptors for ATP have a wide range of physiological roles and comprise a structurally distinct family of ligand-gated trimeric ion channels. The crystal structure of a P2X4 receptor, in combination with mutagenesis studies, has provided a model of the intersubunit ATP-binding sites and identified an extracellular...
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.1201872109
更新日期：2012-03-20 00:00:00
abstract：:There has been much confusion recently about the relative merits of different approaches, osmotic stress, preferential interaction, and crowding, to describe the indirect effect of solutes on macromolecular conformations and reactions. To strengthen all interpretations of measurements and to forestall further unnecess...
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.97.8.3987
更新日期：2000-04-11 00:00:00
abstract：:Reverse transcriptase of murine retroviruses is a monomeric protein of approximately 80,000 daltons, which is encoded by the central portion of the viral pol gene. To prepare large quantities of the enzyme, we have constructed gene fusions between the trpE gene and portions of the pol gene of Moloney murine leukemia v...
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.82.15.4944
更新日期：1985-08-01 00:00:00
abstract：:Most cosmologists now believe that we live in an evolving universe that has been expanding and cooling since its origin about 15 billion years ago. Strong evidence for this standard cosmological model comes from studies of the cosmic microwave background radiation (CMBR), the remnant heat from the initial fireball. Th...
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.95.1.29
更新日期：1998-01-06 00:00:00
abstract：:The efficacy of boron neutron capture therapy (BNCT) for the treatment of intracerebrally implanted rat gliosarcomas was tested. Preferential accumulation of 10B in tumors was achieved by continuous infusion of the sulfhydryl borane dimer, Na4(10)B24H22S2, at a rate of 45-50 micrograms of 10B per g of body weight per ...
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.87.24.9808
更新日期：1990-12-01 00:00:00
abstract：:The rat brain increases >6x in mass from birth to adulthood, presumably through the addition of glial cells and increasing neuronal size, without the addition of neurons. To test this hypothesis, here we investigate quantitatively the postnatal changes in the total number of neuronal and non-neuronal cells in the deve...
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.0804650106
更新日期：2009-08-18 00:00:00
abstract：:At high altitude (HA), carbohydrate (CHO) is thought to be the preferred fuel because of its higher yield of ATP per mole of O2. We used indirect calorimetry and D-[6-3H]glucose infusions to determine total CHO and circulatory glucose utilization during exercise in HA-acclimated and sea level (SL) rats. We hypothesize...
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.95.17.10288
更新日期：1998-08-18 00:00:00
abstract：:This work argues that, in a polarized environment, scientists can minimize the likelihood that the audience's biased processing will lead to rejection of their message if they not only eschew advocacy but also, convey that they are sharers of knowledge faithful to science's way of knowing and respectful of the audienc...
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.1320868111
更新日期：2014-09-16 00:00:00
abstract：:The distribution of oriented, polymerized sickle cell hemoglobin (hemoglobin S) in erythrocytes is visualized with a microscope that produces an image proportional to linear dichroism. Monochromatic light alternately polarized along two perpendicular directions is incident on the sample. The image is focused on a diod...
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.82.19.6527
更新日期：1985-10-01 00:00:00
abstract：:Platelet-derived growth factor receptor (PDGFR) signaling is essential for normal embryonic development in many organisms, including frog, mouse, zebrafish, and sea urchin. The mode of action of PDGFR signaling during early development is poorly understood, however, mostly because inhibition of signaling through eithe...
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.0502885102
更新日期：2005-06-07 00:00:00
abstract：:The replication of simian virus 40 (SV40) DNA is dependent upon a single viral protein [tumor (T) antigen] and multiple cellular proteins. To define the required cellular proteins, we have made use of a cell-free system that supports the replication of plasmid DNA molecules containing the SV40 origin of replication. W...
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.86.10.3584
更新日期：1989-05-01 00:00:00
abstract：:Glycoprotein E (gE) of HSV plays a key role in cell-to-cell spread and virus-induced cell fusion. Here, we report that this function of gE requires the cooperation of tegument proteins UL11, UL16, and UL21. We found that the four proteins come together with very high efficiency to form a complex in transfected cells 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.1212900109
更新日期：2012-11-27 00:00:00
abstract：:PH-30, a sperm surface protein involved in sperm-egg fusion, is composed of two subunits, alpha and beta, which are synthesized as precursors and processed, during sperm development, to yield the mature forms. The mature PH-30 alpha/beta complex resembles certain viral fusion proteins in membrane topology and predicte...
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.90.22.10783
更新日期：1993-11-15 00:00:00
abstract：:A simple method has been developed for fusing synaptic vesicles into spherical structures 20-50 micron in diameter. The method has been applied to purified cholinergic synaptic vesicles from Torpedo electric organ, and the membrane properties of these fused structures have been studied by the "cell"-attached version 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.85.14.5310
更新日期：1988-07-01 00:00:00
abstract：:3-Methylcholanthrene (MCA) skin painting rapidly induced a 100% incidence of thymic lymphomas in RF/J mice. Tumors developed exclusively in cells of the T-lymphocyte lineage and displayed the surface phenotype: Thy-1+, Lyt-1+, Lyt-2+, Qa-1+, H-2K+, H-2D+, TL-, Ig-, Ia-. This phenotype resembled that of cortisone-resis...
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.81.23.7612
更新日期：1984-12-01 00:00:00
abstract：:Studies in experimental animals and humans have stressed the role of the cerebellum in motor skill learning. Yet, the relative importance of the cerebellar cortex and deep nuclei, as well as the nature of the dynamic functional changes occurring between these and other motor-related structures during learning, remains...
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.022615199
更新日期：2002-01-22 00:00:00
abstract：:A 23-kilobase-pair segment of DNA containing the entire mouse serum albumin gene as well as 2.2 kilobase pairs of 5' and 4.3 kilobase pairs of 3' flanking sequences has been introduced into pSV2dhfr, a plasmid in which expression of the mouse dihydrofolate reductase cDNA is under the control of simian virus 40 sequenc...
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.82.3.765
更新日期：1985-02-01 00:00:00
abstract：:We have shown that rat glioma tumors contain a protein that crossreacts with antibody against mouse 2.5S nerve growth factor prepared in rabbit in microcomplement fixation assays and has analogous isoelectric points to all the hybrids of 2.5S nerve growth factor (a dimer). Partially purified protein preparations from ...
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.71.6.2347
更新日期：1974-06-01 00:00:00
abstract：:The conformation of the pressure-dissociated monomer of Arc repressor was characterized by 1H NMR spectroscopy. The NMR spectra of the monomer under pressure (up to 5.0 kbar; 1 bar = 100 kPa) are typical of a molten globule and they are considerably different from those of the native dimer and thermally denatured mono...
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.90.5.1776
更新日期：1993-03-01 00:00:00
abstract：:A full-length cDNA clone encoding a glutamate receptor was isolated from a human brain cDNA library, and the gene product was characterized after expression in Xenopus oocytes. Degenerate PCR primers to conserved regions of published rat brain glutamate receptor sequences amplified a 1-kilobase fragment from a human b...
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.89.4.1443
更新日期：1992-02-15 00:00:00
abstract：:Targeted drug delivery critically depends on the binding selectivity of cargo-transporting colloidal particles. Extensive theoretical work has shown that two factors are necessary to achieve high selectivity for a threshold receptor density: multivalency and weak interactions. Here, we study a model system of DNA-coat...
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.2003968117
更新日期：2020-09-15 00:00:00
abstract：:Proteins from eight eukaryotic families in the cytochrome P-450 superfamily share one region of sequence similarity. This region begins 275-310 amino acids from the amino terminus of each P-450, continues for approximately 170 residues, and ends 35-50 amino acids before the carboxyl terminus. The region can be divided...
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.85.19.7221
更新日期：1988-10-01 00:00:00
