Architecture of a minimal signaling pathway explains the T-cell response to a 1 million-fold variation in antigen affinity and dose.

abstract：:Xenopus oocytes express a gene encoding bovine rhodopsin as well as its SP6 RNA polymerase-derived transcripts and total retinal mRNA. The opsin produced is in unglycosylated (30 kDa) and two glycosylated (35 kDa and 41 kDa) forms. Incubation of the cells expressing the above proteins with 11-cis-retinal generates rho...

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

authors： Khorana HG,Knox BE,Nasi E,Swanson R,Thompson DA

更新日期：1988-11-01 00:00:00

abstract：:Heme A is an essential cofactor for respiratory terminal oxidases and vital for respiration in aerobic organisms. The final step of heme A biosynthesis is formylation of the C-8 methyl group of heme molecule by heme A synthase (HAS). HAS is a heme-containing integral membrane protein, and its structure and reaction me...

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

authors： Niwa S,Takeda K,Kosugi M,Tsutsumi E,Mogi T,Miki K

更新日期：2018-11-20 00:00:00

abstract：:Nitrogen metabolism in bacteria and archaea is regulated by a ubiquitous class of proteins belonging to the P(II)family. P(II) proteins act as sensors of cellular nitrogen, carbon, and energy levels, and they control the activities of a wide range of target proteins by protein-protein interaction. The sensing mechanis...

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

authors： Rajendran C,Gerhardt EC,Bjelic S,Gasperina A,Scarduelli M,Pedrosa FO,Chubatsu LS,Merrick M,Souza EM,Winkler FK,Huergo LF,Li XD

更新日期：2011-11-22 00:00:00

abstract：:Uniparentally inherited mutations to antibiotic resistance and dependence in Chlamydomonas reinhardi exhibit an altered chloroplast ribosome phenotype. Genetic studies demonstrate an absolute correlation between the drug resistance or dependence and the ribosome phenotype in two such mutants. ...

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

authors： Gillham NW,Boynton JE,Burkholder B

更新日期：1970-10-01 00:00:00

abstract：:Synthesis of the iron-storage protein ferritin is thought to be regulated at the translational level by the cytosolic content of chelatable iron. This response to iron is regulated by the iron-modulated binding to ferritin mRNAs of a repressor protein, the iron regulatory element-binding protein. From measurements mad...

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

authors： Eisenstein RS,Garcia-Mayol D,Pettingell W,Munro HN

更新日期：1991-02-01 00:00:00

abstract：:The bioluminescent bacterium Vibrio fischeri initiates a specific, persistent symbiosis in the light organ of the squid Euprymna scolopes. During the early stages of colonization, V. fischeri is exposed to host-derived nitric oxide (NO). Although NO can be both an antimicrobial component of innate immunity and a key s...

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

authors： Wang Y,Dufour YS,Carlson HK,Donohue TJ,Marletta MA,Ruby EG

更新日期：2010-05-04 00:00:00

abstract：:The sequence of a nucleotide region of f1 bacteriophage was determined on a bonded ultrathin acrylamide gel with a discontinuous buffer system by using the dideoxy-DNA sequencing method. This sequence and one other were analyzed for maximal base pairing with tRNAs. The results allow a prediction of the direction and p...

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

authors： Pieczenik G

更新日期：1980-06-01 00:00:00

abstract：:The history of southern Africa involved interactions between indigenous hunter-gatherers and a range of populations that moved into the region. Here we use genome-wide genetic data to show that there are at least two admixture events in the history of Khoisan populations (southern African hunter-gatherers and pastoral...

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

authors： Pickrell JK,Patterson N,Loh PR,Lipson M,Berger B,Stoneking M,Pakendorf B,Reich D

更新日期：2014-02-18 00:00:00

abstract：:Methane can be converted to triose dihydroxyacetone (DHA) by chemical processes with formaldehyde as an intermediate. Carbon dioxide, a by-product of various industries including ethanol/butanol biorefineries, can also be converted to formaldehyde and then to DHA. DHA, upon entry into a cell and phosphorylation to DHA...

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

authors： Wang L,Chauliac D,Rhee MS,Panneerselvam A,Ingram LO,Shanmugam KT

更新日期：2018-04-24 00:00:00

abstract：:The S100A8/S100A9 heterodimer calprotectin (CP) functions in the host response to pathogens through a mechanism termed "nutritional immunity." CP binds Mn(2+) and Zn(2+) with high affinity and starves bacteria of these essential nutrients. Combining biophysical, structural, and microbiological analysis, we identified ...

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

authors： Damo SM,Kehl-Fie TE,Sugitani N,Holt ME,Rathi S,Murphy WJ,Zhang Y,Betz C,Hench L,Fritz G,Skaar EP,Chazin WJ

更新日期：2013-03-05 00:00:00

abstract：:The dorsolateral striatum (DLS) is essential for motor and procedure learning, but the role of DLS spiny projection neurons (SPNs) of direct and indirect pathways, as marked, respectively, by D1 and D2 receptor (D1R and D2R) expression, remains to be clarified. Long-term two-photon calcium imaging of the same neuronal...

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

authors： Sheng MJ,Lu D,Shen ZM,Poo MM

更新日期：2019-05-28 00:00:00

abstract：:During reverse transcription of retroviral RNA, synthesis of (-) strand DNA is primed by a cellular tRNA that anneals to an 18-nt primer binding site within the 5' long terminal repeat. For (+) strand synthesis using a (-) strand DNA template linked to the tRNA primer, only the first 18 nt of tRNA are replicated to re...

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

authors： Burnett BP,McHenry CS

更新日期：1997-07-08 00:00:00

abstract：:We have previously shown that the G protein of vesicular stomatitis virus (VSV-G) can be incorporated into the virions of retroviruses. Since expression of VSV-G is toxic to most mammalian cells, development of stable VSV-G packaging cell lines requires inducible VSV-G expression. We have modified the tetracycline-ind...

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

authors： Chen ST,Iida A,Guo L,Friedmann T,Yee JK

更新日期：1996-09-17 00:00:00

abstract：:Proofreading mechanisms increase specificity in biochemical reactions by allowing for the dissociation of intermediate complexes. These mechanisms disrupt and reset the reaction to undo errors at the cost of increased time of reaction and free energy expenditure. Here, we draw an analogy between proofreading and micro...

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

authors： Murugan A,Huse DA,Leibler S

更新日期：2012-07-24 00:00:00

abstract：:Metazoan arrestins bind to seven-transmembrane (7TM) receptors to regulate function. Aspergillus nidulans PalF, a protein involved in the fungal ambient pH signaling pathway, contains arrestin N-terminal and C-terminal domains and binds strongly to two different regions within the C-terminal cytoplasmic tail of the 7T...

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

authors： Herranz S,Rodríguez JM,Bussink HJ,Sánchez-Ferrero JC,Arst HN Jr,Peñalva MA,Vincent O

更新日期：2005-08-23 00:00:00

abstract：:p38 mitogen-activated protein kinase (MAPK) regulates cytokines in arthritis and is, in turn, regulated by MAPK kinase (MKK) 3 and MKK6. To modulate p38 function but potentially minimize toxicity, we evaluated the utility of targeting MKK3 by using MKK3(-/-) mice. These studies showed that TNF-alpha increased phosphor...

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

authors： Inoue T,Boyle DL,Corr M,Hammaker D,Davis RJ,Flavell RA,Firestein GS

更新日期：2006-04-04 00:00:00

abstract：:FtsZ, the ancestral homolog of eukaryotic tubulins, is a GTPase that assembles into a cytokinetic ring structure essential for cell division in prokaryotic cells. Similar to tubulin, purified FtsZ polymerizes into dynamic protofilaments in the presence of GTP; polymer assembly is accompanied by GTP hydrolysis. We used...

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

authors： Margalit DN,Romberg L,Mets RB,Hebert AM,Mitchison TJ,Kirschner MW,RayChaudhuri D

更新日期：2004-08-10 00:00:00

abstract：:In normal adult rats anesthetized with urethane, intravenous injections of beta-endorphin (30--150 micrograms kg-1) induced a transient fall of blood pressure followed by a small hypertension and a prolonged hypotension. Prior administration of naloxone completely blocked these effects, whereas naloxone, given 1 hr af...

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

authors： Lemaire I,Tseng R,Lemaire S

更新日期：1978-12-01 00:00:00

abstract：:Pyrimethamine (Pyr) targets dihydrofolate reductase of Plasmodium vivax (PvDHFR) as well as other malarial parasites, but its use as antimalarial is hampered by the widespread high resistance. Comparison of the crystal structures of PvDHFR from wild-type and the Pyr-resistant (SP21, Ser-58 --> Arg + Ser-117 --> Asn) s...

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

authors： Kongsaeree P,Khongsuk P,Leartsakulpanich U,Chitnumsub P,Tarnchompoo B,Walkinshaw MD,Yuthavong Y

更新日期：2005-09-13 00:00:00

abstract：:Atherosclerosis is associated with alterations in nitric oxide (NO)/cGMP signaling. In early stages of the disease, inflammatory and possibly other cells produce reactive oxygen species that scavenge vasoprotective NO. In addition to the oxidative stress, expression and activity of enzymes downstream to NO formation m...

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

authors： Melichar VO,Behr-Roussel D,Zabel U,Uttenthal LO,Rodrigo J,Rupin A,Verbeuren TJ,Kumar H S A,Schmidt HH

更新日期：2004-11-23 00:00:00

abstract：:An expression in the exterior algebra of a Peano space yielding Pappus' theorem was originally given by Doubilet, Rota, and Stein [Doubilet, P., Rota, G.-C. & Stein, J. (1974) Stud. Appl. Math. 8, 185-216]. Motivated by an identity of Rota, I give an identity in a Grassmann-Cayley algebra of step 3, involving joins an...

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

authors： Hawrylycz M

更新日期：1994-04-12 00:00:00

abstract：:The repeatability of evolutionary change is difficult to quantify because only a single outcome can usually be observed for any precise set of circumstances. In this study, however, we have quantified the frequency of parallel and divergent genetic changes in 12 initially identical populations of Escherichia coli that...

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

authors： Woods R,Schneider D,Winkworth CL,Riley MA,Lenski RE

更新日期：2006-06-13 00:00:00

abstract：:Protein carboxymethylase, an enzyme capable of methylating proteins and polypeptides, was purified from bovine pituitary. The anterior pituitary hormones, luteinizing hormone, follicle-stimulating hormone, adrenocorticotropic hormone, growth hormone, thyroid-stimulating hormone, and prolactin, were found to be substra...

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

authors： Diliberto EJ Jr,Axelrod J

更新日期：1974-05-01 00:00:00

abstract：:Mononegaviruses are promising tools as oncolytic vectors and transgene delivery vectors for gene therapy and regenerative medicine. By using the Magnet proteins, which reversibly heterodimerize upon blue light illumination, photocontrollable mononegaviruses (measles and rabies viruses) were generated. The Magnet prote...

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

authors： Tahara M,Takishima Y,Miyamoto S,Nakatsu Y,Someya K,Sato M,Tani K,Takeda M

更新日期：2019-06-11 00:00:00

abstract：:Tramadol, previously only known as a synthetic analgesic, has now been found in the bark and wood of roots of the African medicinal tree Nauclea latifolia. At present, no direct evidence is available as to the biosynthetic pathway of its unusual skeleton. To provide guidance as to possible biosynthetic precursors, we ...

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

authors： Romek KM,Nun P,Remaud GS,Silvestre V,Taïwe GS,Lecerf-Schmidt F,Boumendjel A,De Waard M,Robins RJ

更新日期：2015-07-07 00:00:00

abstract：:In Saccharomyces cerevisiae cells harboring a GAL1 promoter-linked beta-galactosidase gene, the simultaneous expression of Escherichia coli DNA topoisomerase I and inactivation of yeast DNA topoisomerases I and II reduces the cellular level of beta-galactosidase to an undetectable level. Analysis of intracellular mRNA...

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

authors： Gartenberg MR,Wang JC

更新日期：1992-12-01 00:00:00

abstract：:Intracellular bacterial pathogens evade the bactericidal functions of mammalian cells by physical escape from their phagosome and replication into the cytoplasm or through the modulation of phagosome maturation and biogenesis of a membrane-bound replicative organelle. Here, we detail in murine primary macrophages the ...

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

authors： Checroun C,Wehrly TD,Fischer ER,Hayes SF,Celli J

更新日期：2006-09-26 00:00:00

abstract：:Hepatitis E virus is responsible for both sporadic and epidemic hepatitis in developing countries. The nonenveloped virus is 27-34 nm in diameter and has been shown to contain a single-strand, positive-sense, polyadenylylated RNA genome of approximately 7.5 kilobases. The nucleotide sequence of the Burma strain of hep...

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

authors： Kaur M,Hyams KC,Purdy MA,Krawczynski K,Ching WM,Fry KE,Reyes GR,Bradley DW,Carl M

更新日期：1992-05-01 00:00:00

abstract：:Monoclonal antibodies were used to isolate nonneutralizable antigenic variants in the hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus. It had been found that a large percentage of virus retains infectivity despite binding neutralizing antibody. This high persistent fraction of nonneutralized virus ...

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

authors： Iorio RM,Bratt MA

更新日期：1985-10-01 00:00:00

abstract：:Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E. huxleyi and show that EhV are emitted...

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

authors： Sharoni S,Trainic M,Schatz D,Lehahn Y,Flores MJ,Bidle KD,Ben-Dor S,Rudich Y,Koren I,Vardi A

更新日期：2015-05-26 00:00:00