Abstract:
:Transcription initiation is a dynamic process in which RNA polymerase (RNAP) and promoter DNA act as partners, changing in response to one another, to produce a polymerase/promoter open complex (RPo) competent for transcription. In Escherichia coli RNAP, region 1.1, the N-terminal 100 residues of sigma(70), is thought to occupy the channel that will hold the DNA downstream of the transcription start site; thus, region 1.1 must move from this channel as RPo is formed. Previous work has also shown that region 1.1 can modulate RPo formation depending on the promoter. For some promoters region 1.1 stimulates the formation of open complexes; at the P(minor) promoter, region 1.1 inhibits this formation. We demonstrate here that the AT-rich P(minor) spacer sequence, rather than promoter recognition elements or downstream DNA, determines the effect of region 1.1 on promoter activity. Using a P(minor) derivative that contains good sigma(70)-dependent DNA elements, we find that the presence of a more GC-rich spacer or a spacer with the complement of the P(minor) sequence results in a promoter that is no longer inhibited by region 1.1. Furthermore, the presence of the P(minor) spacer, the GC-rich spacer, or the complement spacer results in different mobilities of promoter DNA during gel electrophoresis, suggesting that the spacer regions impart differing conformations or curvatures to the DNA. We speculate that the spacer can influence the trajectory or flexibility of DNA as it enters the RNAP channel and that region 1.1 acts as a "gatekeeper" to monitor channel entry.
journal_name
Proc Natl Acad Sci U S Aauthors
Hook-Barnard IG,Hinton DMdoi
10.1073/pnas.0808133106subject
Has Abstractpub_date
2009-01-20 00:00:00pages
737-42issue
3eissn
0027-8424issn
1091-6490pii
0808133106journal_volume
106pub_type
杂志文章abstract::The release of urine, or micturition, serves a fundamental physiological function and, in many species, is critical for social communication. In mice, the pattern of urine release is modulated by external and internal factors and transmitted to the spinal cord via the pontine micturition center (PMC). Here, we exploit...
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.2018078118
更新日期:2021-01-05 00:00:00
abstract::After each round of protein biosynthesis, the posttermination complex (PoTC) consisting of a ribosome, mRNA, and tRNA must be disassembled into its components for a new round of translation. Here, we show that a Saccharomyces cerevisiae model PoTC was disassembled by ATP and eukaryotic elongation factor 3 (eEF3). GTP ...
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.1006247107
更新日期:2010-06-15 00:00:00
abstract::Norharman enhanced the known mutagenicity of 2-acetylaminofluorene derivatives in the Salmonella test system. The mutagenicities of 2-acetylaminofluorene, 2-aminofluorene, and N-hydroxy-2-acetylaminofluorene were enhanced by norharman only when rat liver microsomal enzymes were added, whereas the mutagenicity of N-ace...
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.75.2.928
更新日期:1978-02-01 00:00:00
abstract::The proteins cdc2 and cyclin form a heterodimer (maturation promoting factor) that controls the major events of the cell cycle. A mathematical model for the interactions of cdc2 and cyclin is constructed. Simulation and analysis of the model show that the control system can operate in three modes: as a steady state wi...
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.88.16.7328
更新日期:1991-08-15 00:00:00
abstract::The method of in situ hybridization has become a significant technique for specific-site chromosome mapping. We show that the resolution of in situ hybridization can be increased by hybridizing the probe to stretched prometaphase chromosomes with high-resolution banding obtained after 5-bromodeoxyuridine treatment 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.80.22.6932
更新日期:1983-11-01 00:00:00
abstract::Single-nucleotide polymorphisms (SNPs) in the human ether-a-go-go-related gene 1, hERG1, are associated with cardiac arrhythmias. The Kv11.1 channels encoded by hERG1 are also essential for rhythmic excitability of the pituitary, where they are regulated by thyroid hormone through a signal transduction cascade involvi...
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.0802250105
更新日期:2008-09-23 00:00:00
abstract::A full-length placental alkaline phosphatase (PLAP) cDNA was used to identify and clone the PLAP-like Nagao isozyme gene from human genomic libraries. The entire nucleotide sequence of the gene reveals the existence of 11 exons interrupted by 10 small introns (76-427 base pairs). Putative regulatory sequences have bee...
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.85.9.3024
更新日期:1988-05-01 00:00:00
abstract::The mechanism of contrast enhancement of tumors using magnetic resonance imaging was investigated in MCF7 human breast cancer implanted in nude mice. Dynamic contrast-enhanced images recorded at high spatial resolution were analyzed by an image analysis method based on a physiological model, which included the blood 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.93.13.6247
更新日期:1996-06-25 00:00:00
abstract::An explicitly polarizable force field based exclusively on quantum data is applied to calculations of relative binding affinities of ligands to proteins. Five ligands, differing by replacement of an atom or functional group, in complexes with three serine proteases-trypsin, thrombin, and urokinase-type plasminogen act...
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.0803847105
更新日期:2008-07-29 00:00:00
abstract::Retinoblastoma is a childhood tumor that can arise because of mutant alleles acquired as somatic or germinal mutations. The mutant allele can be carried in the germ line. The mutations creating these alleles act by inactivating copies of a recessive oncogene located within band q14 of chromosome 13 and termed the RB1 ...
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.84.24.9059
更新日期:1987-12-01 00:00:00
abstract::While cells within tissues generate and sense 3D states of strain, the current understanding of the mechanics of fibrous extracellular matrices (ECMs) stems mainly from uniaxial, biaxial, and shear tests. Here, we demonstrate that the multiaxial deformations of fiber networks in 3D cannot be inferred solely based on 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.1815659116
更新日期:2019-04-02 00:00:00
abstract::We have demonstrated the existence of human cytokine synthesis inhibitory factor (CSIF) [interleukin 10 (IL-10)]. cDNA clones encoding human IL-10 (hIL-10) were isolated from a tetanus toxin-specific human T-cell clone. Like mouse IL-10, hIL-10 exhibits strong DNA and amino acid sequence homology to an open reading fr...
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.88.4.1172
更新日期:1991-02-15 00:00:00
abstract::The unfolded protein response (UPR) is an evolutionarily conserved mechanism by which all eukaryotic cells adapt to the accumulation of unfolded proteins in the endoplasmic reticulum (ER). Inositol-requiring kinase 1 (IRE1) and PKR-related ER kinase (PERK) are two type I transmembrane ER-localized protein kinase recep...
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.0606480103
更新日期:2006-09-26 00:00:00
abstract::Covalent attachment of myristic acid (C14:0) to the NH2-terminal glycine residue of a number of cellular, viral, and oncogene-encoded proteins is essential for full expression of their biological function. Substitution of oxygen for methylene groups in this fatty acid does not produce a significant change in chain len...
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.87.21.8511
更新日期:1990-11-01 00:00:00
abstract::Molecular mechanisms that initiate meiosis have been studied in fungi and mammals, but little is known about the mechanisms directing the meiosis transition in other organisms. To elucidate meiosis initiation in plants, we characterized and cloned the ameiotic1 (am1) gene, which affects the transition to meiosis and p...
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.0810115106
更新日期:2009-03-03 00:00:00
abstract::A human collagenase inhibitor (CI) of Mr 28,500 has been extensively characterized in skin fibroblasts and identified in a variety of connective tissues. Because human alveolar macrophages synthesize and secrete both a collagenase and CI that are immunologically and functionally identical to their counterparts in fibr...
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.82.16.5380
更新日期:1985-08-01 00:00:00
abstract::Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Althoug...
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.0910275107
更新日期:2010-09-21 00:00:00
abstract::The inward Na+ current underlying the action potential in nerve is terminated by inactivation. The preceding report shows that deletions within the intracellular linker between domains III and IV remove inactivation, but mutation of conserved basic and paired acidic amino acids has little effect. Here we show that sub...
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.89.22.10910
更新日期:1992-11-15 00:00:00
abstract::Delayed gastric ulcer healing is a well recognized problem associated with the use of cyclooxygenase (COX) inhibitors. In contrast, NO-releasing COX inhibitors do not interfere with ulcer healing. These divergent effects may in part be due to differences in their effects on platelets, which are known to influence ulce...
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.202392199
更新日期:2002-10-01 00:00:00
abstract::We previously purified a 48-kDa protein (p48) that specifically reacts with an antiserum directed against the 12 carboxyl-terminal amino acids of the c-myc gene product. Using an antiserum directed against the purified p48, we have cloned a cDNA from a human expression library. This cDNA hybrid-selects an mRNA that tr...
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.83.18.6741
更新日期:1986-09-01 00:00:00
abstract::The two major disease-causing biotypes of Vibrio cholerae, classical and El Tor, exhibit differences in their epidemic nature. Their behavior in the laboratory also differs in that El Tor strains produce two major virulence factors, cholera toxin (CT) and the toxin coregulated pilus (TCP), only under very restricted g...
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.93.15.7991
更新日期:1996-07-23 00:00:00
abstract::Malignant B lymphocytes from several patients with chronic lymphocytic leukemia (CLL) were examined for reactivity with murine monoclonal antibody 17.109. This antibody, prepared against the rheumatoid factor (RF) paraprotein Sie, recognizes a crossreactive idiotype on 48% of human IgM RF paraproteins, but does not 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.84.9.2916
更新日期:1987-05-01 00:00:00
abstract::Because of increased numbers of recorded pertussis cases in the United States, this study sought to understand the role of nonmedical vaccine exemptions and waning immunity may have had on the resurgence of pertussis in the United States at the community level. We used geospatial scan statistics, SaTScan, version 9.4,...
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.1700240114
更新日期:2017-07-03 00:00:00
abstract::Male mice were injected intraperitoneally with 125 microCi (1 Ci = 3.7 X 10(10) becquerels) of [3H]thymidine at 1-hr intervals and killed 1 hr after the second injection. Testes were prepared for bright-field and electron microscopic autoradiography. Primary spermatocytes, identified by light microscopy to be at the p...
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.77.11.6720
更新日期:1980-11-01 00:00:00
abstract::Fibrodysplasia ossificans progressiva (FOP) patients carry a missense mutation in ACVR1 [617G > A (R206H)] that leads to hyperactivation of BMP-SMAD signaling. Contrary to a previous study, here we show that FOP fibroblasts showed an increased efficiency of induced pluripotent stem cell (iPSC) generation. This 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.1603668113
更新日期:2016-11-15 00:00:00
abstract::A major involvement of IFNalpha in the etiopathogenesis of systemic lupus erythematosus has been suggested by clinical observations, including the increase of serum levels of this cytokine in patients with active disease. Supporting this hypothesis, we have shown that expression of IFNalpha from a recombinant adenovir...
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.0900615106
更新日期:2009-03-31 00:00:00
abstract::Prostate-specific membrane antigen (PSMA) is a type 2 integral membrane glycoprotein that serves as an attractive target for cancer immunotherapy by virtue of its abundant and restricted expression on the surface of prostate carcinomas and the neovasculature of most other solid tumors. However, relatively little is kn...
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.1735443100
更新日期:2003-10-28 00:00:00
abstract::Cellular DNA and RNA were simultaneously quantitated in individual cells of cycling and quiescent populations by flow cytometry. Based on differences in RNA content, two distinct subcompartments, G1A and G1B, were recognized in the G1 phase of exponentially growing cells. After mitosis, cells reside in the low-RNA, G1...
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.77.11.6696
更新日期:1980-11-01 00:00:00
abstract::How colloidal particles interact with each other is one of the key issues that determines our ability to interpret experimental results for phase transitions in colloidal dispersions and our ability to apply colloid science to various industrial processes. The long-accepted theories for answering this question have be...
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.95.26.15169
更新日期:1998-12-22 00:00:00
abstract::The gamma-aminobutyrate-synthesizing enzyme glutamate decarboxylase (GAD; L-glutamate 1-carboxy-lyase, EC 4.1.1.15) is a major target of autoantibodies associated with both early and late stages of pancreatic beta-cell destruction and development of type 1 diabetes. We have used five monoclonal anti-islet-cell antibod...
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.90.7.2832
更新日期:1993-04-01 00:00:00