Replication initiator protein of plasmid R6K autoregulates its own synthesis at the transcriptional step.

abstract：:The PsaF-deficient mutant 3bF of Chlamydomonas reinhardtii was used to modify PsaF by nuclear transformation and site-directed mutagenesis. Four lysine residues in the N-terminal domain of PsaF, which have been postulated to form the positively charged face of a putative amphipathic alpha-helical structure were altere...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hippler M,Drepper F,Haehnel W,Rochaix JD

更新日期：1998-06-23 00:00:00

abstract：:The monomeric VDAC channel shows an accelerated pH titration of its transport properties with a Hill coefficient of about 2. This manifests itself as a sharp peak in conductance noise as well as a fast change in channel selectivity with pH. On the basis of the known structure of this channel, we propose that this coop...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rostovtseva TK,Liu TT,Colombini M,Parsegian VA,Bezrukov SM

更新日期：2000-07-05 00:00:00

abstract：:A fundamental property of ecosystems is a tradeoff between the number and size of habitats: as the number of habitats within a fixed area increases, the average area per habitat must decrease. This tradeoff is termed the "area-heterogeneity tradeoff." Theoretical models suggest that the reduction in habitat sizes unde...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ben-Hur E,Kadmon R

更新日期：2020-03-03 00:00:00

abstract：:Although most nuclear hormone receptors are ligand-dependent transcriptional activators, certain members of this superfamily, such as thyroid hormone receptor (TR) and retinoic acid receptor (RAR), are involved in transcriptional repression. The silencing function of these receptors has been localized to the ligand bi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Nawaz Z,Tsai MJ,O'Malley BW

更新日期：1995-12-05 00:00:00

abstract：:Astrogenesis is repressed in the early embryonic period and occurs in the late embryonic period. A variety of external and internal signals contribute to the sequential differentiation of neural stem cells. Here, we discovered that immune-related CD93 plays a critical negative role in the regulation of astrogenesis in...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Liang Q,Su L,Zhang D,Jiao J

更新日期：2020-04-28 00:00:00

abstract：:von Willebrand factor (vWF) is a multimeric glycoprotein that mediates the adhesion of platelets to the subendothelium by binding to platelet glycoprotein Ib. For human vWF, this interaction can be induced in vitro by the antibiotic ristocetin or the snake venom protein botrocetin. A missense mutation, Gly-561-->Ser, ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rabinowitz I,Tuley EA,Mancuso DJ,Randi AM,Firkin BG,Howard MA,Sadler JE

更新日期：1992-10-15 00:00:00

abstract：:Hookworms are hematophagous nematodes that infect a wide range of mammalian hosts, including humans. There has been speculation for nearly a century as to the identity of the anticoagulant substances) used by these organisms to subvert host hemostasis. Using molecular cloning, we describe a family of potent small prot...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Stassens P,Bergum PW,Gansemans Y,Jespers L,Laroche Y,Huang S,Maki S,Messens J,Lauwereys M,Cappello M,Hotez PJ,Lasters I,Vlasuk GP

更新日期：1996-03-05 00:00:00

abstract：:A model is presented for age-specific selection on the genotypes in a population. Each genotype is assigned a life table that specifies the viability and fecundity of its age classes. Breeding and reproduction occur at regular intervals, and generations overlap. Examples were generated on a digital computer. Gene freq...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Anderson WW,King CE

更新日期：1970-07-01 00:00:00

abstract：:Digestion of mouse L cell mitochondrial DNA with EcoRI restriction endonuclease produces two linear duplex fragments comprising 86.3 +/- 2.0% and 14.2 +/- 1.0% of the circular genome length (16,000 +/- 470 nucleotide pairs). Digestion of human HeLa cell mitochondrial DNA with EcoRI produces three linear duplex fragmen...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Robberson DL,Clayton DA,Morrow JF

更新日期：1974-11-01 00:00:00

abstract：:A computer code to investigate the equilibrium and stability of a diffuse plasma in three dimensions is described that generalizes earlier work on a sharp free boundary model. Toroidal equilibria of a plasma are determined by considering paths of steepest descent associated with a new version of the variational princi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Betancourt O,Garabedian P

更新日期：1976-04-01 00:00:00

abstract：:The Fbw7 (F-box/WD repeat-containing protein 7) ubiquitin ligase targets multiple oncoproteins for degradation and is commonly mutated in cancers. Like other pleiotropic tumor suppressors, Fbw7's complex biology has impeded our understanding of how Fbw7 mutations promote tumorigenesis and hindered the development of t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Davis RJ,Gönen M,Margineantu DH,Handeli S,Swanger J,Hoellerbauer P,Paddison PJ,Gu H,Raftery D,Grim JE,Hockenbery DM,Margolin AA,Clurman BE

更新日期：2018-05-22 00:00:00

abstract：:We have carried out free energy perturbation calculations on DNA double-stranded hexanucleotides. The sequence d(CGCGCG)2 has been "mutated" into d(CGTGCG).d(CGCACG) with the oligonucleotide in the A, B, and Z structural forms, both in vacuo and in aqueous solution. In addition, model free energy calculations have bee...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dang LX,Pearlman DA,Kollman PA

更新日期：1990-06-01 00:00:00

abstract：:Type 2 diabetes mellitus (T2DM) is strongly associated with obesity in most, but not all, ethnic groups, suggesting important ethnic differences in disease susceptibility. Although it is clear that insulin resistance plays a major role in the pathogenesis of T2DM and that insulin resistance is strongly associated with...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Petersen KF,Dufour S,Feng J,Befroy D,Dziura J,Dalla Man C,Cobelli C,Shulman GI

更新日期：2006-11-28 00:00:00

abstract：:We have assayed carbonic anhydrase activity (carbonate dehydratase, carbonate hydro-lyase, EC 4.2.1.1) and bicarbonate permeability in suspensions of broken and intact guinea pig mitochondria by monitoring the disappearance of C16O18O. We found significant activity in preparations from liver and skeletal muscle, but n...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dodgson SJ,Forster RE 2nd,Storey BT,Mela L

更新日期：1980-09-01 00:00:00

abstract：:The T lineage repertoire is shaped by T cell receptor (TCR)-dependent positive and negative thymic selection processes. Using TCR-transgenic (N15tg) beta2-microglobulin-deficient (beta2m-/-) RAG-2(-/-) H-2(b) mice specific for the VSV8 (RGYVYQGL) octapeptide bound to Kb, we identified a single weak agonist peptide var...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ghendler Y,Teng MK,Liu JH,Witte T,Liu J,Kim KS,Kern P,Chang HC,Wang JH,Reinherz EL

更新日期：1998-08-18 00:00:00

abstract：:A key feature of immune evasion for African trypanosomes is the functional specialization of their surface membrane in an invagination known as the flagellar pocket (FP), the cell's sole site of endocytosis and exocytosis. The FP membrane is biochemically distinct yet continuous with those of the cell body and the fla...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gadelha C,Rothery S,Morphew M,McIntosh JR,Severs NJ,Gull K

更新日期：2009-10-13 00:00:00

abstract：:Comparisons were made of the T1 ribonuclease digests of 32P-labeled nucleolar 45S RNA of intact Novikoff hepatoma cells and the RNA synthesized in vitro by isolated nucleoli. Approximately 200 oligonucleotide spots were found in the two-dimensional chromatogram of 45S nucleolar RNA labeled in vivo, which includes frag...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ballal NR,Choi YC,Mouche R,Busche H

更新日期：1977-06-01 00:00:00

abstract：:Multiple biological processes involve the stretching of nucleic acids (NAs). Stretching forces induce local changes in the molecule structure, inhibiting or promoting the binding of proteins, which ultimately affects their functionality. Understanding how a force induces changes in the structure of NAs at the atomic l...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Marin-Gonzalez A,Vilhena JG,Perez R,Moreno-Herrero F

更新日期：2017-07-03 00:00:00

abstract：:Human hepatitis B virus genome encodes a protein, termed HBx, that is widely recognized as a transcriptional transactivator. While HBx does not directly bind cis-acting transcriptional control elements, it has been shown to associate with cellular proteins that bind DNA. Because HBx transactivated a large number of vi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Qadri I,Conaway JW,Conaway RC,Schaack J,Siddiqui A

更新日期：1996-10-01 00:00:00

abstract：:Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face-object associations were scanned during passive rest and during encoding of new related and unre...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schlichting ML,Preston AR

更新日期：2014-11-04 00:00:00

abstract：:A residual sphere is formed by projecting seismic ray travel-time anomalies, relative to a reference Earth model, onto an imaginary sphere around an earthquake. Any dominant slab-like fast band can be determined with spherical harmonic expansion. The technique is useful in detecting trends associated with high-velocit...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Zhou HW,Anderson DL

更新日期：1989-11-01 00:00:00

abstract：:Which network structures favor the rapid spread of new ideas, behaviors, or technologies? This question has been studied extensively using epidemic models. Here we consider a complementary point of view and consider scenarios where the individuals' behavior is the result of a strategic choice among competing alternati...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Montanari A,Saberi A

更新日期：2010-11-23 00:00:00

abstract：:The recent discovery of small molecules targeting the cytochrome bc 1 :aa 3 in Mycobacterium tuberculosis triggered interest in the terminal respiratory oxidases for antituberculosis drug development. The mycobacterial cytochrome...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kalia NP,Hasenoehrl EJ,Ab Rahman NB,Koh VH,Ang MLT,Sajorda DR,Hards K,Grüber G,Alonso S,Cook GM,Berney M,Pethe K

更新日期：2017-07-11 00:00:00

abstract：:The mode of action of "allogeneic supernatant" (the culture supernatant of a 24-hr mixedlymphocyte reaction), has been studied. This factor stimulates the response of spleen cell cultures depleted in thymus-derived lymphoid cells (T-cells) to antigens that elicit a thymus-dependent response. We used a limiting dilutio...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hunter P,Kettman JR

更新日期：1974-02-01 00:00:00

abstract：:To investigate the mechanisms of asbestos-induced carcinogenesis, expression of c-fos and c-jun protooncogenes was examined in rat pleural mesothelial cells and hamster tracheal epithelial cells after exposure to crocidolite or chrysotile asbestos. In contrast to phorbol 12-myristate 13-acetate, which induces rapid an...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Heintz NH,Janssen YM,Mossman BT

更新日期：1993-04-15 00:00:00

abstract：:Antinuclear autoantibodies (ANA) appeared in the plasma of lethally irradiated H-2d histocompatible DBA/2 and BALB/c mice several weeks after intravenous transplantation of 2 to 4 x 10(6) bone marrow cells from 3-week-old animals of the autoimmune New Zealand Black (NZB) strain. Little or no ANA development was observ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Morton JI,Siegel BV

更新日期：1974-06-01 00:00:00

abstract：:The effect of different total enzyme concentrations on the flux through the bacterial phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) in vitro was determined by measuring PTS-mediated carbohydrate phosphorylation at different dilutions of cell-free extract of Escherichia coli. The dependence of the fl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rohwer JM,Postma PW,Kholodenko BN,Westerhoff HV

更新日期：1998-09-01 00:00:00

abstract：:In contrast to the immunosuppressive potential of UVB (280-320 nm) radiation in experimental animals and humans, UVA (320-400 nm) radiation at environmentally relevant doses appears to be immunologically inert. However, such exposure to UVA radiation has been observed unexpectedly to induce resistance to UVB-induced i...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Reeve VE,Tyrrell RM

更新日期：1999-08-03 00:00:00

abstract：:The CRR1 (Copper Response Regulator) locus, required for both activating and repressing target genes of a copper- and hypoxia-sensing pathway in Chlamydomonas, encodes a 1,232-residue candidate transcription factor with a plant-specific DNA-binding domain named SBP, ankyrin repeats, and a C-terminal Cys-rich region, w...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kropat J,Tottey S,Birkenbihl RP,Depège N,Huijser P,Merchant S

更新日期：2005-12-20 00:00:00

abstract：:Human X chromosome DNA was partially purified from a mouse-human hybrid cell line containing a single human chromosome, the X. Enrichment of such DNA was accomplished by two sequential reassociations of radiolabeled hybrid cell DNA with large excesses of mouse DNA. Unreassociated hybrid cell DNA was used as a probe fo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schmeckpeper BJ,Smith KD,Dorman BP,Ruddle FH,Talbot CC Jr

更新日期：1979-12-01 00:00:00