Abstract:
:We have found the two-dimensional electrophoretic technique of O'Farrell to be highly efficient in the detection of charge-change substitutions in a large number of proteins. We have applied this method to determine the level of heterozygosity of the most abundant proteins in Drosophila melanogaster adults from a natural population. The estimate of per-locus heterozygosity obtained from approximately 54 loci screened was 4% with 6 loci polymorphic. This is much lower than overall estimates obtained by standard gel electrophoresis but is not different from estimates for "Group I" enzymes--i.e., those utilizing a narrow spectrum of substrates of intracellular origin. We consider these data to throw open the question of the level of genetic variability in nature.
journal_name
Proc Natl Acad Sci U S Aauthors
Brown AJ,Langley CHdoi
10.1073/pnas.76.5.2381keywords:
subject
Has Abstractpub_date
1979-05-01 00:00:00pages
2381-4issue
5eissn
0027-8424issn
1091-6490journal_volume
76pub_type
杂志文章abstract::The three-dimensional structure of alpha-cobra-toxin, the "long" neurotoxin from the venom of Naja naja siamensis, has been determined at 2.8-A resolution. Crystals grown as hexagonal needles have space group P6522 with unit cell parameters a = b = 74.59 A, c = 42.89 A; one molecule per asymmetric unit. Phases were de...
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.77.5.2400
更新日期:1980-05-01 00:00:00
abstract::The human malaria parasite Plasmodium falciparum can cause infected red blood cells (iRBC) to form rosettes with uninfected RBC, a phenotype associated with severe malaria. Rosetting is mediated by a subset of the Plasmodium falciparum membrane protein 1 (PfEMP1) variant adhesins expressed on the infected host-cell 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.1018692108
更新日期:2011-03-29 00:00:00
abstract::Splenic lymphocytes from a Lewis rat, immunized with purified estradiol-receptor complex of calf uterine nuclei, were fused with cells of three different mouse myeloma lines (P3-X63-Ag8, P3-NSI/I-Ag4-1, and Sp2/0-Ag14) to yield hybridoma cultures, 9% of which produced antibodies to the receptor protein (estrophilin). ...
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.77.1.157
更新日期:1980-01-01 00:00:00
abstract::We studied mutants of E. coli originally identified as being deficient in either endonuclease II (deoxyribonucleate oligonucleotidohydrolase, EC 3.1.4.30) or exonuclease III [deoxyribonucleate (double-stranded) 5'-nucleotidohydrolase, EC 3.1.4.27] activity. Twelve independently derived mutants were tested, including 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.72.2.688
更新日期:1975-02-01 00:00:00
abstract::Antigenic variation of infectious organisms is a major factor in evasion of the host immune response. However, there has been no definitive demonstration of this phenomenon in the malaria parasite Plasmodium falciparum. In this study, cloned parasites were examined serologically and biochemically for the expression 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.88.20.9171
更新日期:1991-10-15 00:00:00
abstract::DNA heteroduplexes with single unpaired bases of the four different kinds were prepared by annealing separated strands of bacteriophage lambda DNA and used to transfect Escherichia coli. Genetic analysis of the progeny phages obtained from transfected bacteria indicates that the E. coli mismatch repair system can reco...
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.83.10.3395
更新日期:1986-05-01 00:00:00
abstract::Puf proteins bind RNA sequence specifically and regulate translation and stability of target mRNAs. A "code" for RNA recognition has been deduced from crystal structures of the Puf protein, human Pumilio1, where each of eight repeats binds an RNA base via a combination of three side chains at conserved positions. Here...
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.0606294103
更新日期:2006-09-12 00:00:00
abstract::Intermolecular energy transfer between appropriately chosen pairs of dyes can be used to induce or enhance banding patterns in human metaphase chromosomes. Energy transfer, calibrated by fluorometric studies on soluble dye.DNA complexes, can also be detected by photometric measurements on cytological preparations of 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.75.11.5650
更新日期:1978-11-01 00:00:00
abstract::Antibodies to DNA in the left-handed (Z) conformation bind to acid-fixed polytene chromosomes of both Chironomus thummi and Drosophila melanogaster, as shown by direct and indirect immunofluorescence. Comparison of the phase-contrast, immunofluorescence, and DNA staining patterns shows a predominant localization of 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.80.14.4344
更新日期:1983-07-01 00:00:00
abstract::A major challenge in research on executive control is to reveal its functional decomposition into underlying neural mechanisms. A typical assumption is that this decomposition occurs solely through anatomically based dissociations. Here we tested an alternative hypothesis that different cognitive control processes may...
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.0808187106
更新日期:2009-05-05 00:00:00
abstract::A perversion in an otherwise uniform helical structure, such as a climbing plant tendril, refers to a kink that connects two helices with opposite chiralities. Such singularity structures are widely seen in natural and artificial mechanical systems, and they provide the fundamental mechanism of helical symmetry breaki...
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.1605621113
更新日期:2016-06-28 00:00:00
abstract::Recent studies have shown that the genes of the gibberellin (GA) biosynthesis pathway in the fungus Gibberella fujikuroi are organized in a cluster of at least seven genes. P450-1 is one of four cytochrome P450 monooxygenase genes in this cluster. Disruption of the P450-1 gene in the GA-producing wild-type strain IMI ...
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.091096298
更新日期:2001-05-08 00:00:00
abstract::In a recent article, Hunter uses the late George Varley and George Gradwell's long-term data on the winter moth (Operophtera brumata) and green tortrix (Tortrix viridana) populations to propose a method of quantifying the relative importance of top-down effects (because of natural enemies) and bottom-up effects (becau...
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.95.18.10661
更新日期:1998-09-01 00:00:00
abstract::Effects of thyrotropin-releasing hormone (TRH; thyroliberin) on membrane electrical properties were studied in the clonal rat anterior pituitary cell (GH3) by continuous recording of the intracellular potential. Application of TRH, which stimulates the release of prolactin and growth hormone from the GH3 cell, elicite...
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.76.11.6017
更新日期:1979-11-01 00:00:00
abstract::BSC-1 cells, epithelial cells of African green monkey kidney origin, show pronounced density-dependent regulation of growth in cell culture. Growth of the cells is rapid to a density of approximately 1.5 x 10(5) cells/per cm(2) in Dulbecco-modified Eagle's medium supplemented with 10% calf serum. Above this "saturatio...
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.75.1.339
更新日期:1978-01-01 00:00:00
abstract::SecA, the translocation ATPase in Escherichia coli, undergoes cycles of conformational changes (insertion/deinsertion) in response to ATP and a preprotein. The membrane-embedded portion of protein translocase, SecYEG, has crucial roles in the SecA-driven preprotein translocation reaction. We previously identified a se...
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.95.23.13567
更新日期:1998-11-10 00:00:00
abstract::Current chemotherapeutic approaches for cancer are in part limited by the inability of drugs to destroy neoplastic cells within poorly vascularized compartments of tumors. We have here systematically assessed anaerobic bacteria for their capacity to grow expansively within avascular compartments of transplanted tumors...
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.251543698
更新日期:2001-12-18 00:00:00
abstract::The downstream box (DB) is a sequence element that enhances translation of several bacterial and phage mRNAs. It has been proposed that the DB enhances translation by base pairing transiently to bases 1469-1483 of 16S rRNA, the so-called anti-DB, during the initiation phase of translation. We have tested this model 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.96.16.8973
更新日期:1999-08-03 00:00:00
abstract::A nonselective ex vivo assay was used to directly detect and quantify zidovudine (AZT)-resistant human immunodeficiency virus type 1 (HIV-1) in the blood of treated and untreated patients. In contrast to previous reports, drug-resistant virus was detected in peripheral blood mononuclear cells of a few of the patients ...
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.90.1.25
更新日期:1993-01-01 00:00:00
abstract::Solution at 2.5-A resolution of the three-dimensional structure of H-2Ld with a single nine-residue peptide provides a structural basis for understanding its unique interaction with beta-2 microglobulin (beta2m) and peptide. Consistent with the biological data that show an unusually weak association of Ld with beta2m,...
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.94.13.6880
更新日期:1997-06-24 00:00:00
abstract::Niemann-Pick type C disease (NP-C) is an inherited neurovisceral lipid storage disorder characterized by progressive neurodegeneration. Most cases of NP-C result from inactivating mutations of NPC1, a recently identified member of a family of genes encoding membrane-bound proteins containing putative sterol sensing do...
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.96.4.1657
更新日期:1999-02-16 00:00:00
abstract::The formation of complex but highly organized neural circuits requires interactions between neurons and glia. During the assembly of the Drosophila olfactory circuit, 50 olfactory receptor neuron (ORN) classes and 50 projection neuron (PN) classes form synaptic connections in 50 glomerular compartments in the antennal...
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.1706533114
更新日期:2017-07-18 00:00:00
abstract::Eph receptor tyrosine kinases and their ephrin ligands regulate cell navigation during normal and oncogenic development. Signaling of Ephs is initiated in a multistep process leading to the assembly of higher-order signaling clusters that set off bidirectional signaling in interacting cells. However, the structural 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.1004148107
更新日期:2010-06-15 00:00:00
abstract::The adenoviral E1A oncogene sensitizes mammalian cells to tumor necrosis factor-alpha (TNF-alpha), in part by repressing the nuclear factor-kappa B (NF-kappa B)-dependent defense against this cytokine. Other E1A activities involve binding to either p300/cyclic AMP response element-binding protein (CBP) or retinoblasto...
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.162082999
更新日期:2002-07-23 00:00:00
abstract::Angiogenin (Ang), an inducer of neovascularization, is secreted by several types of human tumor cells and appears critical for their growth. The murine anti-Ang monoclonal antibody (mAb) 26-2F neutralizes the activities of Ang and dramatically prevents the establishment and metastatic dissemination of human tumor cell...
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.95.8.4579
更新日期:1998-04-14 00:00:00
abstract::The primary structure of proteins S1, the largest protein component of the Escherichia coli ribosome, has been elucidated by determining the amino acid sequence of the protein (from E. coli MRE600) and the nucleotide sequence of the S1 gene (rpsA, of a K-12 strain). The two methods gave results in perfect agreement ex...
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.79.4.1008
更新日期:1982-02-01 00:00:00
abstract::A procedure is described to discover genes that are specifically expressed in human prostate. The procedure involves searching the expressed sequence tag (EST) database for genes that have many related EST sequences from human prostate cDNA libraries but none or few from nonprostate human libraries. The selected candi...
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.95.1.300
更新日期:1998-01-06 00:00:00
abstract::Fusions of the lac operon to genes induced by treatment with sublethal levels of alkylating agents have been selected from random insertions of the Mu-dl(ApRlac) phage by screening for induction of beta-galactosidase activity in the presence of methyl methanesulfonate. Genetic analysis reveals that these fusions resul...
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.81.13.4110
更新日期:1984-07-01 00:00:00
abstract::Partial amino acid sequence of the Ia molecule encoded by the I-E or I-C (I-EC) subregion of the major histocompatibility complex of the mouse are presented. The Ia molecule appears to be comprised of two noncovalently associated polypeptides. The larger subunit, alpha, has an approximate molecular weight of 35,000 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.74.11.5135
更新日期:1977-11-01 00:00:00
abstract::Extracellular vesicles (EVs) secreted by cells present an attractive strategy for developing new therapies, but progress in the field is limited by several issues: The quality of the EVs varies with the type and physiological status of the producer cells; protocols used to isolate the EVs are difficult to scale up; 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.1522297113
更新日期:2016-01-05 00:00:00