Abstract:
:Two adjacent, divergently transcribed, developmentally regulated genes of the maize chloroplast chromosome have different superhelical density/transcriptional activation profiles when transcribed in vitro by the homologous DNA-dependent RNA polymerase. Promoter-specific transcription of the gene for the beta and epsilon subunits of coupling factor 1 (cf1BE) increases and plateaus from templates of increasing negative superhelicity, while transcription of the gene for ribulose bisphosphate carboxylase large subunit (rcL) rises and then falls. Maximal transcription from the two promoters occurs at different template negative superhelical densities and transcription of the two genes is stimulated to different degrees. The different superhelicity profiles alter the molar ratios of the two transcripts over an order of magnitude. Changes in DNA conformation represent one possible mechanism for the differential regulation of the genes.
journal_name
Proc Natl Acad Sci U S Aauthors
Stirdivant SM,Crossland LD,Bogorad Ldoi
10.1073/pnas.82.15.4886subject
Has Abstractpub_date
1985-08-01 00:00:00pages
4886-90issue
15eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::The ability of lysosomes to move within the cytoplasm is important for many cellular functions. This ability is particularly critical in neurons, which comprise vast, highly differentiated domains such as the axon and dendrites. The mechanisms that control lysosome movement in these domains, however, remain poorly und...
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.1616363114
更新日期:2017-04-04 00:00:00
abstract::A mutation in RPB5 (rpb5-9), an essential RNA polymerase subunit assembled into RNA polymerases I, II, and III, revealed a role for this subunit in transcriptional activation. Activation by GAL4-VP16 was impaired upon in vitro transcription with mutant whole-cell extracts. In vivo experiments using inducible reporter ...
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.95.26.15281
更新日期:1998-12-22 00:00:00
abstract::The 2012-2015 drought has left California with severely reduced snowpack, soil moisture, ground water, and reservoir stocks, but the impact of this estimated millennial-scale event on forest health is unknown. We used airborne laser-guided spectroscopy and satellite-based models to assess losses in canopy water conten...
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.1523397113
更新日期:2016-01-12 00:00:00
abstract::The coupling of calcium transport to ATP hydrolysis in rabbit muscle sarcoplasmic reticulum vesicles was determined under steady-state conditions in the presence of 5 mM oxalate and using various concentrations of vesicles to modulate the concentration of free Ca2+ in the medium. This experimental approach takes advan...
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.82.1.98
更新日期:1985-01-01 00:00:00
abstract::Local inhomogeneities in lipid composition play a crucial role in regulation of signal transduction and membrane traffic. Nevertheless, most evidence for microdomains in cells remains indirect, and the nature of membrane inhomogeneities has been difficult to characterize. We used lipid analogs and lipid-anchored prote...
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.231377398
更新日期:2001-11-06 00:00:00
abstract::Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar ...
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.2012745117
更新日期:2020-12-01 00:00:00
abstract::Barttin is an accessory subunit of a subgroup of ClC-type chloride channels expressed in renal and inner ear epithelia. In this study, we examined the effects of barttin on two ClC-K channel isoforms, rat ClC-K1 and human ClC-Kb, using heterologous expression, patch clamping, confocal imaging, and flow cytometry. 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.0601631103
更新日期:2006-07-25 00:00:00
abstract::Treatment of the Daudi Burkitt lymphoma-derived cell line with human interferon alpha, which inhibits cell proliferation in this system, induces differentiation of these B-lymphoid cells into cells with a plasmacytoid phenotype. This differentiation, quantified by the appearance of surface antigens characteristic 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.84.18.6467
更新日期:1987-09-01 00:00:00
abstract::Ezrin plays a key role in coupling signal transduction to cortical cell organization. This actin-membrane linker undergoes a series of conformational changes that modulate its interactions with various partners and its localization in membrane or cytosolic pools. Its mobility and exchange rates within and between thes...
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.192084599
更新日期:2002-10-01 00:00:00
abstract::A galanin receptor protein was solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) from pig brain membranes and then purified by single-step affinity chromatography. The product exhibits saturable and specific binding for galanin with a binding activity of 17 nmol/mg of protein and a dis...
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.90.9.3845
更新日期:1993-05-01 00:00:00
abstract::The thylakoid compartments of plant chloroplasts are a vital destination for copper. Copper is needed to form holo-plastocyanin, which must shuttle electrons between photosystems to convert light into biologically useful chemical energy. Copper can bind tightly to proteins, so it has been hypothesized that copper part...
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.0600142103
更新日期:2006-05-30 00:00:00
abstract::The X gene product encoded by the hepatitis B virus, termed pX, is a promiscuous transactivator of a variety of viral and cellular genes under the control of diverse cis-acting elements. Although pX does not appear to directly bind DNA, pX-responsive elements include the NF-kappa B, AP-1, and CRE (cAMP response elemen...
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.92.9.3819
更新日期:1995-04-25 00:00:00
abstract::Most current diagnostic tests for tuberculosis do not reveal the species or strain of pathogen causing pulmonary infection, which can lead to inappropriate treatment regimens and the spread of disease. Here, we report an assay for mycobacterial strain assignment based on genetically conserved mycobacterial sulfatases....
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.1222041110
更新日期:2013-08-06 00:00:00
abstract::In eukaryotes, ubiquitination is an important posttranslational process achieved through a cascade of ubiquitin-activating (E1), conjugating (E2), and ligase (E3) enzymes. Many pathogenic bacteria deliver virulence factors into the host cell that function as E3 ligases. How these bacterial "Trojan horses" integrate in...
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.1115025109
更新日期:2012-02-07 00:00:00
abstract::Past research found that the ingestion of glucose can enhance self-control. It has been widely assumed that basic physiological processes underlie this effect. We hypothesized that the effect of glucose also depends on people's theories about willpower. Three experiments, both measuring (experiment 1) and manipulating...
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.1313475110
更新日期:2013-09-10 00:00:00
abstract::An 125I-labeled synthetic analog of bovine parathyroid hormone, [8-norleucine,18-norleucine,34-tyrosine]PTH-(1-34) amide ([Nle]PTH-(1-34)-NH2), purified by high-pressure liquid chromatography (HPLC), was employed to label the parathyroid hormone (PTH) receptor in cell lines derived from PTH target tissues: the ROS 17/...
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.84.1.26
更新日期:1987-01-01 00:00:00
abstract::Charcot-Marie-Tooth disease type 4C (CMT4C) is an early-onset, autosomal recessive form of demyelinating neuropathy. The clinical manifestations include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. The gene mutated in CMT4C disease, SH3TC2/KIA...
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.0905523106
更新日期:2009-10-13 00:00:00
abstract::The neural pathway that governs an escape response of Drosophila to sudden changes in light intensity can be artificially induced by electrical stimulation of the brain and monitored by electrical recording from the effector muscles. We have refined previous work in this system to permit reliable ascertainment of two ...
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.93.19.10446
更新日期:1996-09-17 00:00:00
abstract::The grand partition function for a long linear system of alternating alpha and beta sequences with the restraint of a fixed number, N(alphabeta), of alphabeta boundaries depends in an extremely simple way on the alpha-sequence and beta-sequence grand partition functions, xi(alpha) and xi(beta). When the restraint is r...
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.69.5.1165
更新日期:1972-05-01 00:00:00
abstract::Arginine is an amino acid that serves as a substrate for nitric oxide synthase and arginase. As such, arginine has the potential to influence diverse fundamental processes in the lung. Here we report that the arginine transport protein, cationic amino acid transporter (CAT)2, has a critical role in regulating lung inf...
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.0605478103
更新日期:2006-10-03 00:00:00
abstract::The 1,25-dihydroxyvitamin D3 [1,25-(OH)2vitamin D3] analog KH1060 exerts very potent effects on cell proliferation and cell differentiation via the vitamin D receptor (VDR). However, the activities of KH1060 are not associated with an increased affinity for the VDR. We now show that increased stabilization of the VDR-...
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.93.20.10685
更新日期:1996-10-01 00:00:00
abstract::The values of the moment of inertia of the ground-state band of (168)Hf from J = 0(+) to 22(+) are interpreted as involving a revolving cluster with composition increasing steadily from p(10.5)n(14) to p(20.5)n(24), with radius of revolution 6.390 fm. The excited bands from 14(+) to 34(+), 21(-) to 33(-), and 18(-) to...
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.81.10.3261
更新日期:1984-05-01 00:00:00
abstract::The circadian hormone melatonin is synthesized predominantly in the pineal gland by the actions of two pineal-specific enzymes: serotonin N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT). Pineal night-specific ATPase (PINA), another pineal- and night-specific protein we recently identified, is 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.95.4.1876
更新日期:1998-02-17 00:00:00
abstract::During the late Pleistocene, early anatomically modern humans coexisted in Europe with the anatomically archaic Neandertals for some thousand years. Under the recent variants of the multiregional model of human evolution, modern and archaic forms were different but related populations within a single evolving species,...
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.1130343100
更新日期:2003-05-27 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::The biconcave disk shape and deformability of mammalian RBCs rely on the membrane skeleton, a viscoelastic network of short, membrane-associated actin filaments (F-actin) cross-linked by long, flexible spectrin tetramers. Nonmuscle myosin II (NMII) motors exert force on diverse F-actin networks to control cell shapes,...
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.1718285115
更新日期:2018-05-08 00:00:00
abstract::The β-1,3-glucan chrysolaminarin is the main storage polysaccharide of diatoms. In contrast to plants and green algae, diatoms and most other algal groups do not accumulate storage polysaccharides in their plastids. The diatom Phaeodactylum tricornutum possesses only a single gene encoding a putative β-1,3-glucan synt...
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.1719274115
更新日期:2018-05-01 00:00:00
abstract::Herpes simplex virus (HSV) is known to bud from the inner membrane of the nuclear envelope. The structural gene for the glycoprotein gB, which is essential for virus entry and cell fusion induced by HSV type 1, has been cloned in a transient expression vector containing the adenovirus major late promoter, tripartite l...
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.84.16.5675
更新日期:1987-08-01 00:00:00
abstract::We present a simple theory that uses thermodynamic parameters to predict the probability that a protein retains the wild-type structure after one or more random amino acid substitutions. Our theory predicts that for large numbers of substitutions the probability that a protein retains its structure will decline expone...
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.0406744102
更新日期:2005-01-18 00:00:00
abstract::Seeking research funding is an essential part of academic life. Funded projects are primarily collaborative in nature through internal and external partnerships, but what role does funding play in the formulation of these partnerships? Here, by examining over 43,000 scientific projects funded over the past three decad...
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.1513651112
更新日期:2015-12-01 00:00:00