The frailty of adaptive hypotheses for the origins of organismal complexity.

abstract：:The biological realm has inherited symmetries from the physicochemical realm, but with the increasing complexity at higher phenomenological levels of life, some inherited symmetries are broken while novel symmetries appear. These symmetries are of two types, structural and operational. Biological novelties result from...

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

authors： García-Bellido A

更新日期：1996-12-10 00:00:00

abstract：:During protein synthesis, elongation factor G (EF-G) binds to the ribosome and promotes the step of translocation, a process in which tRNA moves from the A to the P site of the ribosome and the mRNA is advanced by one codon. By using three-dimensional cryo-electron microscopy, we have visualized EF-G in a ribosome-EF-...

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

authors： Agrawal RK,Penczek P,Grassucci RA,Frank J

更新日期：1998-05-26 00:00:00

abstract：:The 24-hr intracarotid infusion of plasma-treated glycyl-L-glutamine (3 microM) produced significant enhancement of the monomeric G1 and tetrameric G4 forms of acetylcholinesterase of the cat superior cervical ganglion 48 hr after denervation, in comparison with denervated, noninfused controls. No significant effect o...

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

authors： Koelle GB,Skau KA,Thampi NS,Hymel DM,Han MS

更新日期：1988-08-01 00:00:00

abstract：:Sugar transport across tonoplasts is essential for maintaining cellular sugar homeostasis and metabolic balance in plant cells. It remains unclear, however, how this process is regulated among different classes of sugar transporters. Here, we identified a tonoplast H+/glucose symporter, MdERDL6-1, from apples, which w...

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

authors： Zhu L,Li B,Wu L,Li H,Wang Z,Wei X,Ma B,Zhang Y,Ma F,Ruan YL,Li M

更新日期：2021-01-05 00:00:00

abstract：:The number of red blood cells is normally tightly regulated by a classic homeostatic mechanism based on oxygen sensing in the kidney. Decreased oxygen delivery resulting from anemia induces the production of erythropoietin, which increases red cell production and hence oxygen delivery. Investigations of erythropoietin...

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

authors： Percy MJ,Zhao Q,Flores A,Harrison C,Lappin TR,Maxwell PH,McMullin MF,Lee FS

更新日期：2006-01-17 00:00:00

abstract：:It has long been known that cholera outbreaks can be initiated when Vibrio cholerae, the bacterium that causes cholera, is present in drinking water in sufficient numbers to constitute an infective dose, if ingested by humans. Outbreaks associated with drinking or bathing in unpurified river or brackish water may dire...

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

authors： Lobitz B,Beck L,Huq A,Wood B,Fuchs G,Faruque AS,Colwell R

更新日期：2000-02-15 00:00:00

abstract：:The exact role of the endocannabinoid system (ECS) during spermatogenesis has not been clarified. We used purified germ cell fractions representative of all phases of spermatogenesis and primary cultures of spermatogonia. This approach allowed the precise quantification of the cannabinoid receptor ligands, anandamide ...

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

authors： Grimaldi P,Orlando P,Di Siena S,Lolicato F,Petrosino S,Bisogno T,Geremia R,De Petrocellis L,Di Marzo V

更新日期：2009-07-07 00:00:00

abstract：:Little is known about how genetic variation and epigenetic marks interact to shape differences in behavior. The foraging (for) gene regulates behavioral differences between the rover and sitter Drosophila melanogaster strains, but the molecular mechanisms through which it does so have remained elusive. We show that th...

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

authors： Anreiter I,Kramer JM,Sokolowski MB

更新日期：2017-11-21 00:00:00

abstract：:The nusB5 mutant of Escherichia coli was originally selected for reduced ability to support the antitermination of transcription that is mediated by the gene N product of bacteriophage lambda. By analyzing pulse-labeled RNA with an RNA.DNA filter hybridization technique, we have shown that, in the nusB5 mutant, the ra...

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

authors： Sharrock RA,Gourse RL,Nomura M

更新日期：1985-08-01 00:00:00

abstract：:Methanogenic archaea are major contributors to the global carbon cycle and were long thought to belong exclusively to the euryarchaeal phylum. Discovery of the methanogenesis gene cluster methyl-coenzyme M reductase (Mcr) in the Bathyarchaeota, and thereafter the Verstraetearchaeota, led to a paradigm shift, pushing b...

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

authors： Berghuis BA,Yu FB,Schulz F,Blainey PC,Woyke T,Quake SR

更新日期：2019-03-12 00:00:00

abstract：:Two major themes in the physics of condensed matter are quantum critical phenomena and unconventional superconductivity. These usually occur in the context of competing interactions in systems of strongly correlated electrons. All this interesting physics comes together in the behavior of the recently discovered iron ...

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

authors： Dai J,Si Q,Zhu JX,Abrahams E

更新日期：2009-03-17 00:00:00

abstract：:Reduction of prefrontal cortex glutamic acid decarboxylase (GAD67) and reelin (mRNAs and proteins) expression is the most consistent finding reported by several studies of postmortem schizophrenia (SZ) brains. Converging evidence suggests that the reduced GAD67 and reelin expression in cortical GABAergic interneurons ...

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

authors： Dong E,Agis-Balboa RC,Simonini MV,Grayson DR,Costa E,Guidotti A

更新日期：2005-08-30 00:00:00

abstract：:Gene expression has a stochastic component because of the single-molecule nature of the gene and the small number of copies of individual DNA-binding proteins in the cell. We show how the statistics of such systems can be mapped onto quantum many-body problems. The dynamics of a single gene switch resembles the spin-b...

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

authors： Sasai M,Wolynes PG

更新日期：2003-03-04 00:00:00

abstract：:The x-ray crystal structure of the tetrameric T-antigen-binding lectin from peanut, M(r) 110,000, has been determined by using the multiple isomorphous replacement method and refined to an R value of 0.218 for 22,155 reflections within the 10- to 2.95-A resolution range. Each subunit has essentially the same character...

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

authors： Banerjee R,Mande SC,Ganesh V,Das K,Dhanaraj V,Mahanta SK,Suguna K,Surolia A,Vijayan M

更新日期：1994-01-04 00:00:00

abstract：:A microfluidic mixer is applied to study the kinetics of calmodulin conformational changes upon Ca2+ binding. The device facilitates rapid, uniform mixing by decoupling hydrodynamic focusing from diffusive mixing and accesses time scales of tens of microseconds. The mixer is used in conjunction with multiphoton micros...

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

authors： Park HY,Kim SA,Korlach J,Rhoades E,Kwok LW,Zipfel WR,Waxham MN,Webb WW,Pollack L

更新日期：2008-01-15 00:00:00

abstract：:Tumor necrosis factor-related, activation-induced cytokine (TRANCE), a tumor necrosis factor family member, mediates survival of dendritic cells in the immune system and is required for osteoclast differentiation and activation in the skeleton. We report the skeletal phenotype of TRANCE-deficient mice and its rescue b...

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

authors： Kim N,Odgren PR,Kim DK,Marks SC Jr,Choi Y

更新日期：2000-09-26 00:00:00

abstract：:Understanding the effects of the external environment on bacterial gene expression can provide valuable insights into an array of cellular mechanisms including pathogenesis, drug resistance, and, in the case of Mycobacterium tuberculosis, latency. Because of the absence of poly(A)+ mRNA in prokaryotic organisms, studi...

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

authors： Alland D,Kramnik I,Weisbrod TR,Otsubo L,Cerny R,Miller LP,Jacobs WR Jr,Bloom BR

更新日期：1998-10-27 00:00:00

abstract：:A common complaint among pain patients is that they lose their appetite. These accounts are anecdotal, however, and the neural mechanism underlying pain-induced loss of appetite remains unknown. In this study, we documented the occurrence of appetite loss in patients under migraine attack and investigated the neuronal...

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

authors： Malick A,Jakubowski M,Elmquist JK,Saper CB,Burstein R

更新日期：2001-08-14 00:00:00

abstract：:Recent research on rainforest speciation has highlighted the importance of habitat variation in generating population diversification but lacks evidence of an associated reduction in gene flow. This paper describes a study in which molecular markers were used to examine the effects of allopatric divergence and habitat...

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

authors： Ogden R,Thorpe RS

更新日期：2002-10-15 00:00:00

abstract：:Antibiotic resistance in clinically important bacteria can be mediated by target protection mechanisms, whereby a protein binds to the drug target and protects it from the inhibitory effects of the antibiotic. The most prevalent source of clinical resistance to the antibiotic fusidic acid (FA) is expression of the Fus...

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

authors： Tomlinson JH,Kalverda AP,Calabrese AN

更新日期：2020-10-13 00:00:00

abstract：:Coherent anti-Stokes Raman scattering (CARS) spectra are reported for flavin adenine dinucleotide (FAD) and glucose oxidase (beta-D-glucose:oxygen 1-oxidoreductase; EC 1.1.3.4), in resonance with the 450 nm flavin absorption band. Several isoalloxazine ring modes were observed (1635, 1584, 1507, 1416, and 1359 cm(-1))...

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

authors： Dutta PK,Nestor JR,Spiro TG

更新日期：1977-10-01 00:00:00

abstract：:More than two decades ago, the activation mechanism for the membrane-bound photoreceptor and prototypical G protein-coupled receptor (GPCR) rhodopsin was uncovered. Upon light-induced changes in ligand-receptor interaction, movement of specific transmembrane helices within the receptor opens a crevice at the cytoplasm...

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

authors： Van Eps N,Altenbach C,Caro LN,Latorraca NR,Hollingsworth SA,Dror RO,Ernst OP,Hubbell WL

更新日期：2018-03-06 00:00:00

abstract：:In the northern hemisphere, there is compelling evidence for climate-related advances of spring events, but no such long-term biological time series exist for the southern hemisphere. We have studied a unique data set of dates of first arrival and laying of first eggs over a 55-year period for the entire community of ...

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

authors： Barbraud C,Weimerskirch H

更新日期：2006-04-18 00:00:00

abstract：:Integrated hepatitis B virus (HBV) DNA is almost invariably found in hepatocellular carcinomas (HCC) which develop in HBV carriers. Integrated HBV DNAs from two single-integration HCCs (C3 and C4) have been cloned, and the cellular integration sites have been analyzed. Integrated HBV DNA of C3 is present in chromosome...

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

authors： Hino O,Shows TB,Rogler CE

更新日期：1986-11-01 00:00:00

abstract：:Group A Streptococcus (GAS) and other bacterial pathogens are known to interact with integrins as an initial step in a complex pathway of bacterial ingestion by host cells. Efficient GAS invasion depends on the interaction of bound fibronectin (Fn) with integrins and activation of integrin signaling. TGF-beta1 regulat...

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

authors： Wang B,Li S,Southern PJ,Cleary PP

更新日期：2006-02-14 00:00:00

abstract：:Magnitudes of the larger Soviet underground nuclear weapons tests from the start of the Threshold Test Ban Treaty in 1976 through 1982 are determined for short- and long-period seismic waves. Yields are calculated from the surface wave magnitude for those explosions at the eastern Kazakh test site that triggered a sma...

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

authors： Sykes LR,Cifuentes IL

更新日期：1984-03-01 00:00:00

abstract：:Chromosome-specific gene regulation is known thus far only as a mechanism to equalize the transcriptional activity of the single male X chromosome with that of the two female X chromosomes. In Drosophila melanogaster, a complex including the five Male-Specific Lethal (MSL) proteins, "paints" the male X chromosome, med...

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

authors： Larsson J,Chen JD,Rasheva V,Rasmuson-Lestander A,Pirrotta V

更新日期：2001-05-22 00:00:00

abstract：:Splice variants (SVs) of receptors for growth hormone-releasing hormone (GHRH) have been found in primary human prostate cancers and diverse human cancer cell lines. GHRH antagonists inhibit growth of various experimental human cancers, including pancreatic and colorectal, xenografted into nude mice or cultured in vit...

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

authors： Busto R,Schally AV,Varga JL,Garcia-Fernandez MO,Groot K,Armatis P,Szepeshazi K

更新日期：2002-09-03 00:00:00

abstract：:p-Coumaric acid is the precursor of phenylpropanoids, which are plant secondary metabolites that are beneficial to human health. Tyrosine ammonia lyase catalyzes the production of p-coumaric acid from tyrosine. Because of their photosynthetic ability and biosynthetic versatility, cyanobacteria are promising candidates...

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

authors： Xue Y,Zhang Y,Cheng D,Daddy S,He Q

更新日期：2014-07-01 00:00:00

abstract：:The effects of calcium ion on the Na+ activation gate were studied in squid giant axons. Saxitoxin (STX) was used to block ion entry into Na+ channels without hindering access to the membrane surface, making it possible to distinguish surface effects of calcium from pore-occupancy effects. In the presence of STX, gati...

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

authors： Armstrong CM

更新日期：1999-03-30 00:00:00