Abstract:
:We have isolated several lines of rat embryo cells transformed by simian virus 40. All these lines are fully transformed with regard to saturation density and serum sensitivity, but they differ greatly in their anchorage dependence, as assayed by efficiency of plating in methyl cellulose suspension. This set of lines reveals a consistent relation of plasminogen activator production to plating efficiency in methyl cellulose. T-antigen-positive transformed lines that synthesize activator grow in methyl cellulose suspension, while T-antigen-positive transformed lines that do not synthesize activator fail to form colonies in suspension. Normal rat embryo cells produce very little plasminogen activator and do not grow in methyl cellulose. Sera that permit high levels of plasmin formation and activity support growth in semi-solid medium better than sera whose plasminogen is activated poorly and/or sera that contain inhibitors to plasmin.
journal_name
Proc Natl Acad Sci U S Aauthors
Pollack R,Risser R,Conlon S,Rifkin Ddoi
10.1073/pnas.71.12.4792subject
Has Abstractpub_date
1974-12-01 00:00:00pages
4792-6issue
12eissn
0027-8424issn
1091-6490journal_volume
71pub_type
杂志文章abstract::This study quantifies sex differences in the diurnal and circadian variation of sleep and waking while controlling for menstrual cycle phase and hormonal contraceptive use. We compared the diurnal and circadian variation of sleep and alertness of 8 women studied during two phases of the menstrual cycle and 3 women stu...
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.1524484113
更新日期:2016-09-27 00:00:00
abstract::Glutamyl-tRNA (Glu-tRNA), formed by Glu-tRNA synthetase (GluRS), is a substrate for protein biosynthesis and tetrapyrrole formation by the C(5) pathway. In this route Glu-tRNA is transformed to delta-aminolevulinic acid, the universal precursor of tetrapyrroles (e.g., heme and chlorophyll) by the action of Glu-tRNA 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.0611611104
更新日期:2007-02-27 00:00:00
abstract::The cochlear implant (CI) is a neuroprosthesis that allows profoundly deaf patients to recover speech intelligibility. This recovery goes through long-term adaptative processes to build coherent percepts from the coarse information delivered by the implant. Here we analyzed the longitudinal postimplantation evolution ...
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.0609419104
更新日期:2007-04-24 00:00:00
abstract::Foraminifera are unicellular organisms that inhabit the oceans in various ecosystems. The majority of the foraminifera precipitate calcitic shells and are among the major CaCO(3) producers in the oceans. They comprise an important component of the global carbon cycle and also provide valuable paleoceanographic informa...
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.0906636106
更新日期:2009-12-22 00:00:00
abstract::Starving Bacillus subtilis cells execute a gene expression program resulting in the formation of stress-resistant spores. Sporulation master regulator, Spo0A, is activated by a phosphorelay and controls the expression of a multitude of genes, including the forespore-specific sigma factor σ(F) and the mother cell-speci...
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.1213974109
更新日期:2012-12-11 00:00:00
abstract::Selective blockade of gene expression by designed small molecules is a fundamental challenge at the interface of chemistry, biology, and medicine. Transcription factors have been among the most elusive targets in genetics and drug discovery, but the fields of chemical biology and genetics have evolved to a point where...
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.1312473110
更新日期:2013-09-24 00:00:00
abstract::Dendritic cells (DCs) and B cells present antigen-derived peptides bound to MHC class II (MHC II) molecules for recognition by CD4-positive T lymphocytes. DCs control the intracellular traffic of peptide-MHC II complexes by regulating the ubiquitination of MHC II. In resting or "immature" DCs, ubiquitinated MHC II mol...
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.1202977109
更新日期:2012-06-05 00:00:00
abstract::Peripheral blood mononuclear cells of 10 out of 26 patients with human immunodeficiency virus type 1 (HIV-1) released IgE-binding factors, as determined by two independent assays. The formation of the factors by the mononuclear cells was enhanced by incubation of the cells with homologous IgE. In the presence of IgE, ...
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.85.23.9214
更新日期:1988-12-01 00:00:00
abstract::We have recently characterized a transposable element, ISH1, which inactivates the bacterio-opsin (BO) gene in two purple membrane-deficient (Pum-) mutants of Halobacterium halobium. Examination of nine additional Pum- mutants now shows that in all of these the BO gene has been inactivated by insertion of one of two 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.80.8.2201
更新日期:1983-04-01 00:00:00
abstract::Somatic cell hybridization of mouse erythroleukemia (MEL) cells and HEL cells, a human erythroleukemia line that produces fetal (gamma) but fails to express adult (beta) globin, was used to test whether the expression of the two human globin genes is regulated cis or trans. An experimental approach using anti-human gl...
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.82.3.780
更新日期:1985-02-01 00:00:00
abstract::The fusion of inner mitochondrial membranes requires dynamin-like GTPases, Mgm1 in yeast and OPA1 in mammals, but how they mediate membrane fusion is poorly understood. Here, we determined the crystal structure of Saccharomyces cerevisiae short Mgm1 (s-Mgm1) in complex with GDP. It revealed an N-terminal GTPase (G) 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.1919116117
更新日期:2020-02-25 00:00:00
abstract::Methods for the construction of ordered nanoscale arrays have been implicated in fields ranging from separation technologies to microelectronics. Yet, despite the plethora of nanoscale structures assembled in nature that use a templating strategy, chemists have been unable to replicate this success. A technology is 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.0711308105
更新日期:2008-02-05 00:00:00
abstract::Fluorescein isothiocyanate (FITC) was used to label the rabbit intestinal brush border Na+-glucose carrier, identify the carrier protein on sodium dodecyl sulfate/polyacrylamide gel electrophoresis, and monitor the effect of ions and substrates on fluorescence quenching. Enriched brush border preparations were employe...
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.81.7.2223
更新日期:1984-04-01 00:00:00
abstract::Recombinant DNA molecule of phage lambda formed in Escherichia coli in the presence of chloramphenicol and/or rifampin can be assayed by their biological activity. recA- cells were found to be capable of forming recombinant lambda phage DNA in the presence of chloramphenicol. The relatively high recA-independent recom...
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.74.9.3932
更新日期:1977-09-01 00:00:00
abstract::Dominant mutations in the maize homeobox gene knotted1 (kn1) act nonautonomously during maize leaf development, indicating that Kn1 is involved in the generation or transmission of a developmental signal that passes from the inner layers of the leaf to epidermal cells. We previously found that this nonautonomous activ...
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.052484099
更新日期:2002-03-19 00:00:00
abstract::Protein database searches frequently can reveal biologically significant sequence relationships useful in understanding structure and function. Weak but meaningful sequence patterns can be obscured, however, by other similarities due only to chance. By searching a database for multiple as opposed to pairwise alignment...
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.87.14.5509
更新日期:1990-07-01 00:00:00
abstract::Aging and disease processes may be due to deleterious and irreversible changes produced by free radical reactions. The enzyme copper-zinc superoxide dismutase (Cu-Zn SOD; superoxide:superoxide oxidoreductase, EC 1.15.1.1) performs a protective function by scavenging superoxide radicals. The Cu-Zn SOD gene (Sod) cloned...
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.87.11.4270
更新日期:1990-06-01 00:00:00
abstract::Genetic potentials (pedigree-estimated breeding value) for milk and for fat were compared in cows grouped according to subclinical stage of bovine leukemia virus infection. Genetic potential for milk production was significantly greater in seropositive cows with persistent lymphocytosis (622 +/- 72 kg) and in seroposi...
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.86.3.993
更新日期:1989-02-01 00:00:00
abstract::The importance of core histones in the regulation of DNA function by chromatin is clear. However, little is known about the role of the linker histone. We investigated the role of H1 in Saccharomyces cerevisiae during extensive transcriptional reprogramming in stationary phase. Although the levels of linker histone Hh...
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.0806337105
更新日期:2008-09-30 00:00:00
abstract::Signaling through the Toll receptor is required for dorsal/ventral polarity in Drosophila embryos, and also plays an evolutionarily conserved role in the immune response. Upon ligand binding, Toll appears to multimerize and activate the associated kinase, Pelle. However, the immediate downstream targets of Pelle have ...
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.141235698
更新日期:2001-07-17 00:00:00
abstract::The detection, stabilization, and repair of stress-induced damage are essential requirements for cellular life. All cells respond to osmotic stress-induced water loss with increased expression of genes that mediate accumulation of organic osmolytes, solutes that function as chemical chaperones and restore osmotic home...
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.0602987103
更新日期:2006-08-08 00:00:00
abstract::Let T(k) (epsilon)(lambda; t(1),..., t(k)) = rho(X(t) (1))q(epsilon)(X(t) (2) - X(t) (1))... q(epsilon)(X(t(k) ) - X(t(k) )-1), where X(t) is a Brownian motion in R(2), lambda(dx) = rho(x)dx, and q(epsilon) converges to Dirac's delta function as epsilon downward arrow 0. The self-intersection local times of order k ar...
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.83.11.3575
更新日期:1986-06-01 00:00:00
abstract::Protein Hal is a human gamma4 heavy-chain disease protein whose molecular weight is reduced from 55,000 to 25,000 in 6 M guanidine due to the lack of disulfide bonds between heavy chains. Studies of aminoacid sequence indicate that it contains a gap of about 240 residues, starting 10 residues from the N-terminal end 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.70.4.1073
更新日期:1973-04-01 00:00:00
abstract::The I-J subregion of the mouse major histocompatibility complex has been reported to encode antigenic determinants expressed by suppressor T cells. Previously, cosmid clones were obtained from mouse sperm DNA that contain all of the sequences between the I-A and I-E subregions, where I-J has been mapped genetically. H...
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.80.18.5704
更新日期:1983-09-01 00:00:00
abstract::A fundamental, yet underexplored, materials system is the interface between biological molecules and inorganic surfaces. In an elemental approach to this problem, we have systematically examined the adhesion of amino acids to a series of inorganic surfaces including metals, insulators, and semiconductors. 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.0408565102
更新日期:2005-05-31 00:00:00
abstract::Observations made during the last ten years with the Chandra X-ray Observatory have shed much light on the cooling gas in the centers of clusters of galaxies and the role of active galactic nucleus (AGN) heating. Cooling of the hot intracluster medium in cluster centers can feed the supermassive black holes found in 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.0913904107
更新日期:2010-04-20 00:00:00
abstract::A highly purified fraction obtained from scrapie (263-K strain)-infected hamsters' brains by an alternative procedure without proteinase K treatment contained a protease-resistant form of the scrapie precursor protein (PrPSc) and infectivity of 9.9 +/- 0.7 log LD50/ml. Polyclonal antibodies produced against hamster sc...
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.87.16.6373
更新日期:1990-08-01 00:00:00
abstract::DNA-based identification depends on the probability that two different individuals have the same phenotype, which is given by kinship theory. Together with the large and consistent body of evidence on human population structure, kinship theory provides a sound basis for forensic use of DNA markers. ...
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.89.7.2556
更新日期:1992-04-01 00:00:00
abstract::The localization of calmodulin, a calcium-dependent modulator of many enzymes, was studied in rat liver, skeletal muscle, and adrenal slices. Calmodulin is found in liver cytoplasm, nucleus, and plasma membrane. Much of the cytoplasmic calmodulin is associated with glycogen particles presumably bound to enzymes involv...
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.77.1.366
更新日期:1980-01-01 00:00:00
abstract::In a search for a model cell system that might allow studies of the function of the Rho-related GTPase CDC42Hs in human cells, we measured the content and distribution of CDC42Hs in monocytes that were differentiating into macrophages. The total content of this protein increased 5- to 6-fold in phorbol ester-treated h...
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.91.10.4263
更新日期:1994-05-10 00:00:00