Abstract:
:Using currently available gene fusion techniques, we have constructed plasmids that direct the overproduction of the carboxyl-terminal two-thirds of DNA polymerase I, corresponding to the proteolytically derived "Klenow fragment." We have obtained overproduction amounting to several percent of the cellular protein using constructs in which expression is directed either from the lac promoter or from the leftward promoter of phage lambda. The polymerase fragment has been purified to homogeneity from such overproducing strains by a rapid three-stage purification procedure, yielding material capable of carrying out the same reactions (polymerization, 3' labeling, DNA sequence analysis) as the proteolytically derived fragment. The availability of such overproducing strains should greatly facilitate structural and mechanistic studies of DNA polymerase I. Moreover, the techniques we have described for the cloning and expression of a gene fragment should be generally applicable for the study of protein structure and function in other systems.
journal_name
Proc Natl Acad Sci U S Aauthors
Joyce CM,Grindley NDdoi
10.1073/pnas.80.7.1830subject
Has Abstractpub_date
1983-04-01 00:00:00pages
1830-4issue
7eissn
0027-8424issn
1091-6490journal_volume
80pub_type
杂志文章abstract::Spatial working memory or short-term place memory is impaired in schizophrenia. The efficiency of antipsychotic drugs, particularly of typical antipsychotics, on cognitive deficit in schizophrenia remains disputable. Inhibition of serotonin (5-HT) 2A/2C receptors is important for cognitive improvement in schizophrenic...
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.0711273105
更新日期:2008-01-22 00:00:00
abstract::CD28 is a 44-kDa glycoprotein expressed as a homodimer on the surface of a major subset of human T cells. Previous studies have demonstrated that the binding of monoclonal antibodies to the CD28 surface antigen can augment the proliferation of purified human T cells stimulated with suboptimal doses of mitogens or anti...
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.86.4.1333
更新日期:1989-02-01 00:00:00
abstract::Combined intracellular and microfluorometric recording techniques were used to evaluate whether the inhibition by cholinergic or adrenergic transmitters of the Ca2(+)-activated potassium current (IAHP) in hippocampal CA3 pyramidal cells was mediated by an alteration of depolarization-induced change in cytosolic free C...
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.87.11.4083
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abstract::We have recently established that several mRNAs encode the PR264/SC35 splicing factor and that their expression is related to that of c-Myb in human hematopoietic cells. We now report that the various PR264 mRNAs whose expression is transactivated by c-Myb proteins encode an identical PR264/SC35 polypeptide. These mRN...
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.91.3.932
更新日期:1994-02-01 00:00:00
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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.1907290116
更新日期:2019-08-27 00:00:00
abstract::The prefrontal cortex (PFC) is assumed to contribute to goal-directed episodic encoding by exerting cognitive control on medial temporal lobe (MTL) memory processes. However, it is thus far unclear to what extent the contribution of PFC-MTL interactions to memory manifests at a structural anatomical level. We combined...
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.1013287108
更新日期:2011-03-29 00:00:00
abstract::Scleroderma is a chronic systemic disease that leads to fibrosis of affected organs. Transforming growth factor (TGF) beta has been implicated in the pathogenesis of scleroderma. Smad proteins are signaling transducers downstream from TGF-beta receptors. Three families of Smads have been identified: (i) receptor-regul...
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
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更新日期:2002-03-19 00:00:00
abstract::Nonribosomal peptide synthetases (NRPSs) usually catalyze the biosynthesis of peptide natural products by sequential selection, activation, and condensation of amino acid precursors. It was reported that some fatty acids, α-ketoacids, and α-hydroxyacids originating from amino acid metabolism as well as polyketide-deri...
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.1204232109
更新日期:2012-05-29 00:00:00
abstract::We have recently shown that the expression of nestin, the neural stem cell marker protein, is expressed in bulge-area stem cells of the hair follicle. We used transgenic mice with GFP expression driven by the nestin regulatory element [nestin-driven GFP (ND-GFP)]. The ND-GFP stem cells give rise to the outer-root shea...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.0501263102
更新日期:2005-04-12 00:00:00
abstract::Cancer immunotherapy has emerged as a promising therapeutic intervention. However, complete and durable responses are only seen in a fraction of patients who have cancer. A key factor that limits therapeutic success is the infiltration of tumors by cells of the myeloid lineage. The inhibitory receptor signal regulator...
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.1710877114
更新日期:2017-12-05 00:00:00
abstract::We recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 88 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results sugg...
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.85.1.193
更新日期:1988-01-01 00:00:00
abstract::The use of computers to simulate the functions of complex biological macromolecules is essential to achieve a microscopic description of biological processes and to model and interpret experimental data. Here we apply theoretical computational approaches to investigate the fidelity of T7 DNA polymerase, divided into d...
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.0408173102
更新日期:2005-05-10 00:00:00
abstract::Several overlapping chromosomal deletions spanning the albino locus in the mouse cause perinatal lethality when homozygous and a block in the transcriptional induction of various unlinked hepatocyte-specific genes. Studies of such lethal albino deletion homozygotes in perinatal stages revealed a deficiency in the tran...
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.89.14.6540
更新日期:1992-07-15 00:00:00
abstract::The retinylidene chromophore mutant (Y185F) of bacteriorhodopsin, in which Tyr-185 is substituted by phenylalanine, is examined and compared with wild-type bacteriorhodopsin expressed in Escherichia coli; both were reinstituted similarly in vesicles. The Y185F mutant shows (at least) two distinct spectra at neutral pH...
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.87.11.4103
更新日期:1990-06-01 00:00:00
abstract::Evolutionary theory reveals that punishment is effective in promoting cooperation and maintaining social norms. Although it is accepted that emotions are connected to punishment decisions, there remains substantial debate over why humans use costly punishment. Here we show experimentally that constraints on emotion 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.0502399102
更新日期:2005-05-17 00:00:00
abstract::Synovial membranes in patients with rheumatoid arthritis as well as other types of chronic destructive inflammatory arthritis contain infiltrates of activated T lymphocytes that probably contribute to the pathogenesis of the disease. In an effort to elucidate the nature of these infiltrates, interleukin 2 (IL-2)-respo...
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.85.4.1179
更新日期:1988-02-01 00:00:00
abstract::After pollen grains germinate on the stigma, pollen tubes traverse the extracellular matrix of the style on their way to the ovules. We previously characterized two pollen-specific, receptor-like kinases, LePRK1 and LePRK2, from tomato (Lycopersicon esculentum). Their structure and immunolocalization pattern and the s...
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.0631728100
更新日期:2003-05-27 00:00:00
abstract::Sequence comparisons of genomes or expressed sequence tags (ESTs) from related organisms provide insight into functional conservation and diversification. We compare the sequences of ESTs from the male accessory gland of Drosophila simulans to their orthologs in its close relative Drosophila melanogaster, and demonstr...
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.131568198
更新日期:2001-06-19 00:00:00
abstract::Keratins 14 and 5 are the structural hallmarks of the basal keratinocytes of the epidermis and outer root sheath (ORS) of the hair follicle. Their genes are controlled in a tissue-specific manner and thus serve as useful tools to elucidate the regulatory mechanisms involved in keratinocyte-specific transcription. Prev...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2001-02-27 00:00:00
abstract::Neuropeptide B (NPB) and neuropeptide W (NPW) have been recently identified as ligands for the G protein-coupled receptor (GPR) 7 and GPR8. The precise in vivo role of this neuropeptide-receptor pathway has not been fully demonstrated. In this paper, we report that NPB-deficient mice manifest a mild adult-onset obesit...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2005-07-12 00:00:00
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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.0237384100
更新日期:2003-03-04 00:00:00
abstract::The exocytosis of AMPA receptors is a key step in long-term potentiation (LTP), yet the timing and location of exocytosis and the signaling pathways involved in exocytosis during synaptic plasticity are not fully understood. Here we combine two-photon uncaging with two-photon imaging of a fluorescent label of surface ...
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.0913875107
更新日期:2010-09-07 00:00:00
abstract::Adenosine has been identified in the anterior pituitary gland and is secreted from cultured folliculostellate (FS) cells. To determine whether adenosine controls the secretion of anterior pituitary hormones in vitro, adenosine was incubated with anterior pituitaries. It stimulated prolactin (PRL) release at the lowest...
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.95.13.7795
更新日期:1998-06-23 00:00:00
abstract::The replisome, the multiprotein system responsible for genome duplication, is a highly dynamic complex displaying a large number of different enzyme activities. Recently, the Saccharomyces cerevisiae minimal replication reaction has been successfully reconstituted in vitro. This provided an opportunity to uncover 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.1711291114
更新日期:2017-10-03 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::Salmonella enterica serovar Typhi can colonize the gallbladder and persist in an asymptomatic carrier state that is frequently associated with the presence of gallstones. We have shown that salmonellae form bile-mediated biofilms on human gallstones and cholesterol-coated surfaces in vitro. Here, we test the hypothesi...
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.1000862107
更新日期:2010-03-02 00:00:00
abstract::Although much of the brain's functional organization is genetically predetermined, it appears that some noninnate functions can come to depend on dedicated and segregated neural tissue. In this paper, we describe a series of experiments that have investigated the neural development and organization of one such noninna...
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.95.3.847
更新日期:1998-02-03 00:00:00
abstract::A gene-transfer approach was used to explore the function of the BCL2 (B-cell lymphoma/leukemia 2) gene in a human T-cell line, Jurkat. Though stable introduction of a BCL2 expression plasmid into Jurkat T cells was by itself insufficient, the combined transfer of BCL2 and MYC genes markedly enhanced the tumorigenicit...
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.87.10.3660
更新日期:1990-05-01 00:00:00
abstract::Protein 4.1R (4.1R) is a multifunctional component of the red cell membrane. It forms a ternary complex with actin and spectrin, which defines the nodal junctions of the membrane-skeletal network, and its attachment to the transmembrane protein glycophorin C creates a bridge between the protein network and the membran...
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.0803225105
更新日期:2008-06-10 00:00:00
abstract::The role of intraspecific and interspecific interactions in structuring biotic communities at fine spatial scales is well documented, but the signature of species interactions at coarser spatial scales is unclear. We present evidence that species interactions may be a significant factor in mediating the regional assem...
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.0914089107
更新日期:2010-03-16 00:00:00