Decomposition of the linking number of a closed ribbon: A problem from molecular biology.

abstract：:Most small multicopy antibiotic-resistance plasmids of Staphylococcus aureus contain a major axis of hyphenated dyad symmetry (palA) that is required for normal replication and stability, although located outside of the minimal replicon. Rearrangements affecting palA cause plasmid instability, a marked reduction in co...

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

authors： Gruss AD,Ross HF,Novick RP

更新日期：1987-04-01 00:00:00

abstract：:Cry proteins produced by Bacillus thuringiensis are selective biodegradable insecticides used increasingly in bacterial insecticides and transgenic plants as alternatives to synthetic chemical insecticides. However, the potential for development of resistance and cross-resistance in target insect populations to Cry pr...

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

authors： Wirth MC,Georghiou GP,Federici BA

更新日期：1997-09-30 00:00:00

abstract：:p21(WAF1/Cip1) is one of the best characterized downstream targets of p53, and the growth suppressing function of this cyclin-dependent kinase inhibitor is well established. However, whether p21 exerts a tumor-suppressing function of its own remains to be established. We report here that, similarly to loss of p53, dis...

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

authors： Topley GI,Okuyama R,Gonzales JG,Conti C,Dotto GP

更新日期：1999-08-03 00:00:00

abstract：:The antigenic sites of horse and rat cytochromes c in the major antigenic region were compared using a panel of variant cytochromes c and a large number of BALB/c mouse monoclonal antibodies (mAbs) in competitive ELISAs. The major antigenic region of cytochrome c is located on the surface opposite of that containing t...

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

authors： Jemmerson R,Johnson JG

更新日期：1991-05-15 00:00:00

abstract：:A yeast gene has been identified by screening for DNA replication mutants using a permeabilized cell replication assay. The mutant is temperature sensitive for growth and shows a cell cycle phenotype typical of DNA replication mutants. RNA synthesis is normal in the mutant but DNA synthesis ceases upon shift to the no...

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

authors： Budd ME,Campbell JL

更新日期：1995-08-15 00:00:00

abstract：:Quinate:NAD(+) 3-oxidoreductase (EC 1.1.1.24) from carrot cell suspension cultures has previously been shown to be activated by phosphorylation and inactivated by dephosphorylation. Here it is shown that the reactivation of the inactivated quinate:NAD(+) oxidoreductase is an enzyme-mediated process that requires ATP a...

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

authors： Ranjeva R,Refeno G,Boudet AM,Marmé D

更新日期：1983-09-01 00:00:00

abstract：:It has been recently shown that malignant activation of the c-has/bas proto-oncogene in T24 human bladder carcinoma cells was mediated by a single point mutation. A deoxyguanosine located at position 35 of the first exon of this proto-oncogene was substituted by thymidine. These findings predicted that the resulting o...

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

authors： Santos E,Reddy EP,Pulciani S,Feldmann RJ,Barbacid M

更新日期：1983-08-01 00:00:00

abstract：:Vaccination is the most effective medical intervention ever introduced and, together with clean water and sanitation, it has eliminated a large part of the infectious diseases that once killed millions of people. A recent study concluded that since 1924 in the United States alone, vaccines have prevented 40 million ca...

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

authors： Rappuoli R,Pizza M,Del Giudice G,De Gregorio E

更新日期：2014-08-26 00:00:00

abstract：:The expression of the adenovirus (Ad) early coding region 1a (E1a) is required for virus-induced cell transformation and for the activation of other viral early genes and some cellular genes. Two overlapping early mRNAs of 13S and 12S that are transcribed from this region code for a 289-amino acid protein and a 243-am...

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

authors： Hurwitz DR,Chinnadurai G

更新日期：1985-01-01 00:00:00

abstract：:The molecular circadian clocks in the mammalian retina are locally synchronized by environmental light cycles independent of the suprachiasmatic nuclei (SCN) in the brain. Unexpectedly, this entrainment does not require rods, cones, or melanopsin (OPN4), possibly suggesting the involvement of another retinal photopigm...

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

authors： Buhr ED,Yue WW,Ren X,Jiang Z,Liao HW,Mei X,Vemaraju S,Nguyen MT,Reed RR,Lang RA,Yau KW,Van Gelder RN

更新日期：2015-10-20 00:00:00

abstract：:Obesity is associated with increased risk for developing pancreatic cancer, and it is suggested that insulin resistance provides the missing link. Here we demonstrate that under the context of genetic susceptibility, a high fat diet (HFD) predisposes mice with oncogenic K-ras activation to accelerated pancreatic intra...

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

authors： Khasawneh J,Schulz MD,Walch A,Rozman J,Hrabe de Angelis M,Klingenspor M,Buck A,Schwaiger M,Saur D,Schmid RM,Klöppel G,Sipos B,Greten FR,Arkan MC

更新日期：2009-03-03 00:00:00

abstract：:To clone the gene for the human Na+/H+ antiporter, we first constructed a stable mouse LTK- cell line (LAP1) lacking Na+/H+ antiport activity. Second, we devised a selective technique based on acid killing that specifically sorts out cells expressing low levels of Na+/H+ antiport activity from a population of antiport...

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

authors： Franchi A,Perucca-Lostanlen D,Pouyssegur J

更新日期：1986-12-01 00:00:00

abstract：:Mammalian cells present a fingerprint of their proteome to the adaptive immune system through the display of endogenous peptides on MHC-I complexes. MHC-I-bound peptides originate from protein degradation by the proteasome, suggesting that stably folded, long-lived proteins could evade monitoring. Here, we investigate...

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

authors： Trentini DB,Pecoraro M,Tiwary S,Cox J,Mann M,Hipp MS,Hartl FU

更新日期：2020-02-25 00:00:00

abstract：:Helicobacter hepaticus-infected Rag2(-/-) mice emulate many aspects of human inflammatory bowel disease, including the development of colitis and colon cancer. To elucidate mechanisms of inflammation-induced carcinogenesis, we undertook a comprehensive analysis of histopathology, molecular damage, and gene expression ...

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

authors： Mangerich A,Knutson CG,Parry NM,Muthupalani S,Ye W,Prestwich E,Cui L,McFaline JL,Mobley M,Ge Z,Taghizadeh K,Wishnok JS,Wogan GN,Fox JG,Tannenbaum SR,Dedon PC

更新日期：2012-07-03 00:00:00

abstract：:Recent laboratory studies have demonstrated that isoprene oxidation products can partition to atmospheric aerosols by reacting with condensed phase sulfuric acid, forming low-volatility organosulfate compounds. We have identified organosulfate compounds in free tropospheric aerosols by single particle mass spectrometr...

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

authors： Froyd KD,Murphy SM,Murphy DM,de Gouw JA,Eddingsaas NC,Wennberg PO

更新日期：2010-12-14 00:00:00

abstract：:Experimental allergic encephalomyelitis (EAE), an autoimmune model of multiple sclerosis, is a complex disease influenced by genetic, intrinsic, and environmental factors. In this study, we questioned whether parent-of-origin effects influence EAE, using reciprocal F2 intercross progeny generated between EAE-susceptib...

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

authors： Teuscher C,Noubade R,Spach K,McElvany B,Bunn JY,Fillmore PD,Zachary JF,Blankenhorn EP

更新日期：2006-05-23 00:00:00

abstract：:Osteocalcin, a bone-specific protein and marker of the mature osteoblast, is expressed only in nonproliferating osteoblasts in a mineralizing extracellular matrix, while type I collagen is expressed in proliferating cells. The nuclear proteins encoded by the c-fos and c-jun protooncogenes are expressed during the prol...

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

authors： Owen TA,Bortell R,Yocum SA,Smock SL,Zhang M,Abate C,Shalhoub V,Aronin N,Wright KL,van Wijnen AJ

更新日期：1990-12-01 00:00:00

abstract：:Soil systems are being increasingly exposed to the interactive effects of biological invasions and climate change, with rising temperatures expected to benefit alien over indigenous species. We assessed this expectation for an important soil-dwelling group, the springtails, by determining whether alien species show br...

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

authors： Janion-Scheepers C,Phillips L,Sgrò CM,Duffy GA,Hallas R,Chown SL

更新日期：2018-01-02 00:00:00

abstract：:The oligodendrocyte (Od), a glial cell that produces myelin in the central nervous system, may be a target for autoreactive T cells in autoimmune demyelinating processes, although not expressing major histocompatibility complex (MHC) products. To analyze Od-T-cell interactions, we selected from normal SJL/J mouse sple...

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

authors： Jewtoukoff V,Lebar R,Bach MA

更新日期：1989-04-01 00:00:00

abstract：:Childhood exposure to low-level lead can permanently reduce intelligence, but the neurobiologic mechanism for this effect is unknown. We examined the impact of lead exposure on the development of cortical columns, using the rodent barrel field as a model. In all areas of mammalian neocortex, cortical columns constitut...

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

authors： Wilson MA,Johnston MV,Goldstein GW,Blue ME

更新日期：2000-05-09 00:00:00

abstract：:Although neutrophils are known to be fundamental in controlling innate immune responses, their role in regulating adaptive immunity is just starting to be appreciated. We report that human neutrophils exposed to pregnancy hormones progesterone and estriol promote the establishment of maternal tolerance through the ind...

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

authors： Nadkarni S,Smith J,Sferruzzi-Perri AN,Ledwozyw A,Kishore M,Haas R,Mauro C,Williams DJ,Farsky SH,Marelli-Berg FM,Perretti M

更新日期：2016-12-27 00:00:00

abstract：:The assembly of heterogeneous nuclear RNA (hnRNA) into ribonucleoprotein (RNP) particles has been investigated during in vitro transcription in isolated nuclei. Approximately 80% of the in vitro transcription observed in mouse Friend erythroleukemia cell nuclei is attributable to the activity of RNA polymerase II. In ...

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

authors： Economidis IV,Pederson T

更新日期：1982-03-01 00:00:00

abstract：:Cytochrome c oxidase (CcO) uses the energy released by reduction of O2 to H2O to drive eight charges from the high pH to low pH side of the membrane, increasing the electrochemical gradient. Four electrons and protons are used for chemistry, while four more protons are pumped. Proton pumping requires that residues on ...

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

authors： Lu J,Gunner MR

更新日期：2014-08-26 00:00:00

abstract：:Natural resistance-associated macrophage protein (Nramp) family transporters catalyze uptake of essential divalent transition metals like iron and manganese. To discriminate against abundant competitors, the Nramp metal-binding site should favor softer transition metals, which interact either covalently or ionically w...

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

authors： Bozzi AT,Bane LB,Weihofen WA,McCabe AL,Singharoy A,Chipot CJ,Schulten K,Gaudet R

更新日期：2016-09-13 00:00:00

abstract：:A mechanistic understanding of the controls on carbon storage and losses is essential for our capacity to predict and mitigate human impacts on the global carbon cycle. Plant litter decomposition is an important first step for carbon and nutrient turnover, and litter inputs and losses are essential in determining soil...

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

authors： Austin AT,Méndez MS,Ballaré CL

更新日期：2016-04-19 00:00:00

abstract：:New Zealand Black (NZB) mice develop after 16 weeks of age an autoimmune and lymphoproliferative disease which is a model for systemic lupus erythematosus and lymphoid malignancy in humans. At this age, the mice manifest a progressive decline in T lymphocyte (thymus-derived lymphocyte) functions and serum thymosin lev...

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

authors： Dauphinee MJ,Talal N,Goldstein AL,White A

更新日期：1974-07-01 00:00:00

abstract：:In normal messenger RNA for the human beta-globin chain, nucleotide sequences have been identified which can be matched to the amino-acid sequence of the abnormally long segment of the beta-chain of hemoglobin Cranston. The finding of these sequences strengthens the hypothesis that the betaCranston chain arose by a fr...

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

authors： Forget BG,Marotta CA,Weissman SM,Cohen-Solal M

更新日期：1975-09-01 00:00:00

abstract：:In yeast meiosis, crossing-over between homologues is dependent upon double-strand breaks. We demonstrate that the occurrence of these breaks is independent of pairing between homologues by showing that they occur with normal frequency, timing, and position in the absence of a homologue. This observation supports mode...

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

authors： Gilbertson LA,Stahl FW

更新日期：1994-12-06 00:00:00

abstract：:Psychopathy is associated with persistent antisocial behavior and a striking lack of regret for the consequences of that behavior. Although explanatory models for psychopathy have largely focused on deficits in affective responsiveness, recent work indicates that aberrant value-based decision making may also play a ro...

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

authors： Baskin-Sommers A,Stuppy-Sullivan AM,Buckholtz JW

更新日期：2016-12-13 00:00:00

abstract：:To reduce greenhouse gas emissions from deforestation, Indonesia instituted a nationwide moratorium on new license areas ("concessions") for oil palm plantations, timber plantations, and logging activity on primary forests and peat lands after May 2011. Here we indirectly evaluate the effectiveness of this policy usin...

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

authors： Busch J,Ferretti-Gallon K,Engelmann J,Wright M,Austin KG,Stolle F,Turubanova S,Potapov PV,Margono B,Hansen MC,Baccini A

更新日期：2015-02-03 00:00:00