Observing the formation of ice and organic crystals in active sites.

abstract：:Distribution studies disclosed that all major cerebral arteries and cortical arterioles of the cat were invested with fine varicose nerve fibers that contained calcitonin gene-related peptide (CGRP)-like immunoreactivity; the trigeminal ganglia likewise contained CGRP immunoreactivity. Sequential immunostaining with a...

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

authors： McCulloch J,Uddman R,Kingman TA,Edvinsson L

更新日期：1986-08-01 00:00:00

abstract：:A defect in the yeast GEF1 gene, a CLC chloride channel homolog leads to an iron requirement and cation sensitivity. The iron requirement is due to a failure to load Cu2+ onto a component of the iron uptake system, Fet3. This process, which requires both Gef1 and the Menkes disease Cu2+-ATPase yeast homolog Ccc2, occu...

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

authors： Gaxiola RA,Yuan DS,Klausner RD,Fink GR

更新日期：1998-03-31 00:00:00

abstract：:The activation of additional promoter sites by production of an alternative sigma subunit for RNA polymerase is a common strategy for the coordinate regulation of gene expression. Many alternative sigma factors control genes for specialized, and often narrowly distributed, functions. For example, most of the alternati...

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

authors： Chen YF,Helmann JD

更新日期：1992-06-01 00:00:00

abstract：:The trace metals nickel and platinum, which are not substrates for ferrochelatase and thus do not form heme in biological systems, were found to act similaryl to cobalt, and heme itself, in regulating heme metabolism in liver and kidney. These metals induced heme oxygenase activity in both organs with the peak of indu...

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

authors： Maines MD,Kappas A

更新日期：1977-05-01 00:00:00

abstract：:Two-dimensional 1H NMR investigations were used to locate elements of regular secondary structure in the human complement protein C3a (the des-Arg77 derivative) in solution. The results were compared to a refined crystal structure based on the 3.2-A resolution structure of des-Arg77-C3a [Huber, R., Scholze, H., Paques...

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

authors： Nettesheim DG,Edalji RP,Mollison KW,Greer J,Zuiderweg ER

更新日期：1988-07-01 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：:Cell-specific activation of the transcription factor sigma F during sporulation in Bacillus subtilis is controlled by a regulatory pathway involving the proteins SpoIIE, SpoIIAA, and SpoIIAB. SpoIIAB is an antagonist of sigma F, and SpoIIAA, which is capable of overcoming SpoIIAB-mediated inhibition of sigma F, is an ...

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

authors： Arigoni F,Duncan L,Alper S,Losick R,Stragier P

更新日期：1996-04-16 00:00:00

abstract：:Bacteria in the human oral cavity often grow in an attached multispecies biofilm community. Members of this community display defined interactions that have an impact on the physiology of the individual and the group. Here, we show that during coculture growth with streptococci, the oral pathogen Aggregatibacter actin...

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

authors： Ramsey MM,Whiteley M

更新日期：2009-02-03 00:00:00

abstract：:The betaalpha barrel is the common protein fold of numerous enzymes and was proposed recently to be the result of gene duplication and fusion of an ancient half-barrel. The initial enzyme of shikimate biosynthesis possesses the additional feature of feedback regulation. The crystal structure and kinetic studies on chi...

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

authors： Hartmann M,Schneider TR,Pfeil A,Heinrich G,Lipscomb WN,Braus GH

更新日期：2003-02-04 00:00:00

abstract：:Cytosine, 5-methylcytosine, and 5-hydroxymethylcytosine were identified during translocation of single DNA template strands through a modified Mycobacterium smegmatis porin A (M2MspA) nanopore under control of phi29 DNA polymerase. This identification was based on three consecutive ionic current states that correspond...

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

authors： Schreiber J,Wescoe ZL,Abu-Shumays R,Vivian JT,Baatar B,Karplus K,Akeson M

更新日期：2013-11-19 00:00:00

abstract：:Extracellular stimuli regulate neuronal differentiation and subtype specification during brain development, although the intracellular signaling pathways that mediate these processes remain largely unclear. We now show that the PDK1-Akt pathway regulates differentiation of telencephalic neural precursor cells (NPCs). ...

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

authors： Oishi K,Watatani K,Itoh Y,Okano H,Guillemot F,Nakajima K,Gotoh Y

更新日期：2009-08-04 00:00:00

abstract：:Recent advances in metabolic engineering have demonstrated that microbial biosynthesis can provide a viable alternative to chemical synthesis for the production of bulk and fine chemicals. Introduction of a new biosynthetic pathway typically requires the expression of multiple heterologous enzymes in the production ho...

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

authors： Michener JK,Nielsen J,Smolke CD

更新日期：2012-11-20 00:00:00

abstract：:The mammalian retina contains an autonomous circadian clock system that controls many physiological functions within this tissue. Previous studies on young mice have reported that removal of the key circadian clock gene Bmal1 from the retina affects the circadian regulation of visual function, but does not affect phot...

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

authors： Baba K,Piano I,Lyuboslavsky P,Chrenek MA,Sellers JT,Zhang S,Gargini C,He L,Tosini G,Iuvone PM

更新日期：2018-12-18 00:00:00

abstract：:When various wild strains of Penicillium lanosum and Aspergillus niger were placed in the same mild laboratory environment, their frequencies of new spontaneous mutations were clearly related to whether they had been isolated from a region of high or low microclimatic stress. In the mild environment, the total frequen...

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

authors： Lamb BC,Mandaokar S,Bahsoun B,Grishkan I,Nevo E

更新日期：2008-04-15 00:00:00

abstract：:T cell-dependent B-cell responses decline with age, suggesting defective CD4 T-cell function. CD4 memory T cells from individuals older than 65 y displayed increased and sustained transcription of the dual-specific phosphatase 4 (DUSP4) that shortened expression of CD40-ligand (CD40L) and inducible T-cell costimulator...

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

authors： Yu M,Li G,Lee WW,Yuan M,Cui D,Weyand CM,Goronzy JJ

更新日期：2012-04-10 00:00:00

abstract：:Replication of HIV-1 and N-tropic murine leukemia virus (N-MLV) is restricted in a number of different primate cells. In some cell lines, cross-saturation experiments suggest that the two viruses are interacting with the same restriction factor. Recently, Trim5alpha protein from rhesus monkey was found to restrict HIV...

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

authors： Yap MW,Nisole S,Lynch C,Stoye JP

更新日期：2004-07-20 00:00:00

abstract：:Male relationships in most species of mammals generally are characterized by intense intrasexual competition, with little bonding among unrelated individuals. In contrast, human societies are characterized by high levels of cooperation and strong bonds among both related and unrelated males. The emergence of cooperati...

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

authors： Patzelt A,Kopp GH,Ndao I,Kalbitzer U,Zinner D,Fischer J

更新日期：2014-10-14 00:00:00

abstract：:Addition of acetylcholine to growing cultures of mouse neuroblastoma cells induced a 37-fold increase in the specific activity of acetylcholinesterase (EC 3.1.1.7). Morphological changes, consisting of neurite-extensions, were also observed during the logarithmic phase of growth of cells stimulated with acetylcholine....

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

authors： Harkins J,Arsenault M,Schlesinger K,Kates J

更新日期：1972-11-01 00:00:00

abstract：:An electrophoretic karyotype of Aspergillus nidulans has been obtained using contour-clamped homogeneous electric field gel electrophoresis. Six chromosomal bands were separated, with two of the bands migrating as doublets. Using the Schizosaccharomyces pombe and Saccharomyces cerevisiae chromosomes as size standards,...

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

authors： Brody H,Carbon J

更新日期：1989-08-01 00:00:00

abstract：:We have investigated the biochemical basis for negative regulation of interleukin 2 receptor alpha-chain (IL-2R alpha) gene expression. Transient transfection studies employing internally deleted forms of the IL-2R alpha promoter localized a negative regulatory element (NRE) between nucleotides -400 and -368 relative ...

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

authors： Smith MR,Greene WC

更新日期：1989-11-01 00:00:00

abstract：:Cell-free DNA shed by cancer cells has been shown to be a rich source of putative tumor-specific biomarkers. Because cell-free DNA from brain and spinal cord tumors cannot usually be detected in the blood, we studied whether the cerebrospinal fluid (CSF) that bathes the CNS is enriched for tumor DNA, here termed CSF-t...

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

authors： Wang Y,Springer S,Zhang M,McMahon KW,Kinde I,Dobbyn L,Ptak J,Brem H,Chaichana K,Gallia GL,Gokaslan ZL,Groves ML,Jallo GI,Lim M,Olivi A,Quinones-Hinojosa A,Rigamonti D,Riggins GJ,Sciubba DM,Weingart JD,Wolinsky JP

更新日期：2015-08-04 00:00:00

abstract：:The role played by postsynaptic alpha-adrenergic receptors in the stimulation of pineal N-acetyltransferase (EC 2.3.1.5) and [3H]melatonin production was investigated in the rat. In vivo studies indicated that phenylephrine, an alpha-adrenergic agonist, potentiated and prolonged the effects of isoproterenol, a beta-ad...

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

authors： Klein DC,Sugden D,Weller JL

更新日期：1983-01-01 00:00:00

abstract：:Cancer patients and tumor-bearing mice possess serum antibodies that recognize antigens expressed by cancer cells at the time of diagnosis. After diagnosis, cancers progress to more aggressive stages, most often by acquiring new genetic changes that can give rise to new proteins, some of which are antigenic. However, ...

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

authors： Spiotto MT,Reth MA,Schreiber H

更新日期：2003-04-29 00:00:00

abstract：:The role of rising atmospheric CO2 in modulating estuarine carbonate system dynamics remains poorly characterized, likely due to myriad processes driving the complex chemistry in these habitats. We reconstructed the full carbonate system of an estuarine seagrass habitat for a summer period of 2.5 months utilizing a co...

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

authors： Pacella SR,Brown CA,Waldbusser GG,Labiosa RG,Hales B

更新日期：2018-04-10 00:00:00

abstract：:Paleoclimate studies suggest that increased global warmth during the Eocene epoch was greatly amplified at high latitudes, a state that climate models cannot fully reproduce. However, proxy estimates of Eocene near-Antarctic sea surface temperatures (SSTs) have produced widely divergent results at similar latitudes, w...

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

authors： Douglas PM,Affek HP,Ivany LC,Houben AJ,Sijp WP,Sluijs A,Schouten S,Pagani M

更新日期：2014-05-06 00:00:00

abstract：:The symbiotic bacterium Wolbachia pipientis has been considered unique in its ability to cause multiple reproductive anomalies in its arthropod hosts. Here we report that an undescribed bacterium is vertically transmitted and associated with thelytokous parthenogenetic reproduction in Encarsia, a genus of parasitoid w...

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

authors： Zchori-Fein E,Gottlieb Y,Kelly SE,Brown JK,Wilson JM,Karr TL,Hunter MS

更新日期：2001-10-23 00:00:00

abstract：:Thyroid hormone (TH) metabolism, mediated by deiodinase types 1, 2, and 3 (D1, D2, and D3) is profoundly affected by acute illness. We examined the role of TH metabolism during ventilator-induced lung injury (VILI) in mice. Mice exposed to VILI recapitulated the serum TH findings of acute illness, namely a decrease in...

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

authors： Barca-Mayo O,Liao XH,DiCosmo C,Dumitrescu A,Moreno-Vinasco L,Wade MS,Sammani S,Mirzapoiazova T,Garcia JG,Refetoff S,Weiss RE

更新日期：2011-12-06 00:00:00

abstract：:In the wake of the COVID-19 pandemic many countries implemented containment measures to reduce disease transmission. Studies using digital data sources show that the mobility of individuals was effectively reduced in multiple countries. However, it remains unclear whether these reductions caused deeper structural chan...

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

authors： Schlosser F,Maier BF,Jack O,Hinrichs D,Zachariae A,Brockmann D

更新日期：2020-12-29 00:00:00

abstract：:A central role for phenotypic plasticity in adaptive evolution is often posited yet lacks empirical support. Selection for the stable production of an induced phenotype is hypothesized to modify the regulation of preexisting developmental pathways, producing rapid adaptive change. We examined the role of plasticity in...

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

authors： Scoville AG,Pfrender ME

更新日期：2010-03-02 00:00:00

abstract：:Polymorphism may play an important role in speciation because new species could originate from the distinctive morphs observed in polymorphic populations. However, much remains to be understood about the process by which morphs found new species. To detail the steps of this mode of speciation, we studied the geographi...

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

authors： Corl A,Davis AR,Kuchta SR,Sinervo B

更新日期：2010-03-02 00:00:00