Abstract:
:Aquaporin (AQP) 4 is the predominant water channel in the mammalian brain, abundantly expressed in the blood-brain and brain-cerebrospinal fluid interfaces of glial cells. Its function in cerebral water balance has implications in neuropathological disorders, including brain edema, stroke, and head injuries. The 1.8-A crystal structure reveals the molecular basis for the water selectivity of the channel. Unlike the case in the structures of water-selective AQPs AqpZ and AQP1, the asparagines of the 2 Asn-Pro-Ala motifs do not hydrogen bond to the same water molecule; instead, they bond to 2 different water molecules in the center of the channel. Molecular dynamics simulations were performed to ask how this observation bears on the proposed mechanisms for how AQPs remain totally insulating to any proton conductance while maintaining a single file of hydrogen bonded water molecules throughout the channel.
journal_name
Proc Natl Acad Sci U S Aauthors
Ho JD,Yeh R,Sandstrom A,Chorny I,Harries WE,Robbins RA,Miercke LJ,Stroud RMdoi
10.1073/pnas.0902725106subject
Has Abstractpub_date
2009-05-05 00:00:00pages
7437-42issue
18eissn
0027-8424issn
1091-6490pii
0902725106journal_volume
106pub_type
杂志文章abstract::The neural crest (NC) emerges from combinatorial inductive events occurring within its progenitor domain, the neural border (NB). Several transcription factors act early at the NB, but the initiating molecular events remain elusive. Recent data from basal vertebrates suggest that ap2 might have been critical for NC em...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1010740107
更新日期:2011-01-04 00:00:00
abstract::Ovarian cancer remains the most lethal gynecologic malignancy. We analyzed the mutational landscape of 64 primary, 41 metastatic, and 17 recurrent fresh-frozen tumors from 77 patients along with matched normal DNA, by whole-exome sequencing (WES). We also sequenced 13 pairs of synchronous bilateral ovarian cancer (SBO...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1814027116
更新日期:2019-01-08 00:00:00
abstract::Never before have individuals had to adapt to social environments defined by such magnitudes of ethnic diversity and cultural differentiation. However, neurobiological evidence informing about strategies to reduce xenophobic sentiment and foster altruistic cooperation with outsiders is scarce. In a series of experimen...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,随机对照试验
doi:10.1073/pnas.1705853114
更新日期:2017-08-29 00:00:00
abstract::The surface distributions of three different membrane integral proteins, beta2-microglobulin (part of the histocompatibility antigen complex), aminopeptidase (alpha-aminoacyl-peptide hydrolase; EC 3.4.11.2), and the Na+,K+-ATPase (ATP phosphohydrolase; EC 3.6.1.3) on human fibroblasts grown in monolayer culture have b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.12.5584
更新日期:1977-12-01 00:00:00
abstract::We report substantially improved performance of high-power quantum cascade lasers (QCLs) by using epitaxial-side-down mounting that provides superior heat dissipation properties. We used aluminum nitride as the heatsink material and gold-tin eutectic solder. We have obtained continuous wave power output of 450 mW at 2...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0600859103
更新日期:2006-03-28 00:00:00
abstract::The three lipin phosphatidate phosphatase (PAP) enzymes catalyze a step in glycerolipid biosynthesis, the conversion of phosphatidate to diacylglycerol. Lipin-1 is critical for lipid synthesis and homeostasis in adipose tissue, liver, muscle, and peripheral nerves. Little is known about the physiological role of lipin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1205221109
更新日期:2012-09-11 00:00:00
abstract::Molecular clocks have been used to date the divergence of humans and chimpanzees for nearly four decades. Nonetheless, this date and its confidence interval remain to be firmly established. In an effort to generate a genomic view of the human-chimpanzee divergence, we have analyzed 167 nuclear protein-coding genes and...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0509585102
更新日期:2005-12-27 00:00:00
abstract::We present the use of our recently described multiple-loci polymorphic DNA markers ("alumorphs") for linkage mapping of the human genome. By using the polymerase chain reaction (PCR) with an Alu-specific primer we could reveal, in a single experiment, up to 20 genomic polymorphisms seen as the presence or absence of a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.18.8448
更新日期:1992-09-15 00:00:00
abstract::In the absence of adaptive immunity displayed by animals, plants respond locally to biotic challenge via inducible basal defense networks activated through recognition and response to conserved pathogen-associated molecular patterns. In addition, immunity can be induced in tissues remote from infection sites by system...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0605423104
更新日期:2007-01-16 00:00:00
abstract::We have previously described how T and natural killer (NK) lineage commitment proceeds from common T/NK progenitors (p-T/NK) in the murine fetal thymus (FT), with the use of a clonal assay system capable of discriminating p-T/NK from unipotent T or NK lineage-committed progenitors (p-T and p-NK, respectively). The mol...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.091537598
更新日期:2001-04-24 00:00:00
abstract::alpha-1-Antitrypsin is a serum protein that inhibits many proteolytic enzymes. Recently, it was suggested that the alpha-1-antitrypsin-trypsin complex is an acyl ester analogous to the acyl intermediate that forms between trypsin and its substrates. In previous work we showed that the alpha-1-antitrypsin-trypsin compl...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.10.4311
更新日期:1977-10-01 00:00:00
abstract::The template for transcription and replication of negative-stranded RNA viruses is a ribonucleoprotein structure, the nucleocapsid. We have developed a system that supports assembly of the negative-stranded RNA genome of a defective interfering (DI) particle of vesicular stomatitis virus (VSV) into a nucleocapsid in v...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.20.7511
更新日期:1988-10-01 00:00:00
abstract::Because synaptic vesicle exocytosis is a nano-mechanical process, it should be influenced by the mechanical properties of the cell membrane to which the vesicle fuses. By dissolving surfactants at various concentrations in the neuronal membrane, we have perturbed mechanical properties of the membrane and have found th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0809714105
更新日期:2008-11-18 00:00:00
abstract::Subunits A and B of chloroplast glyceraldehyde-3-phosphate dehydrogenase are synthesized as higher molecular weight precursors when polyadenylylated mRNA from angiosperm seedlings is translated in vitro by wheat germ ribosomes. The in vivo levels of mRNA coding for these precursors are strongly light dependent, and th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.24.7624
更新日期:1982-12-01 00:00:00
abstract::Among the most striking aspects of the movement of many animal groups are their sudden coherent changes in direction. Recent observations of locusts and starlings have shown that this directional switching is an intrinsic property of their motion. Similar direction switches are seen in self-propelled particle and othe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0811195106
更新日期:2009-04-07 00:00:00
abstract::To monitor inaccuracy in gene expression in living cells, we designed an experimental system in the bacterium Bacillus subtilis whereby spontaneous errors can be visualized and quantified at a single-cell level. Our strategy was to introduce mutations into a chromosomally encoded gfp allele, such that errors in protei...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0912989107
更新日期:2010-06-22 00:00:00
abstract::The epothilones represent a promising class of natural product-based antitumor drug candidates. Although these compounds operate through a microtubule stabilization mechanism similar to that of taxol, the epothilones offer a major potential therapeutic advantage in that they retain their activity against multidrug-res...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0804773105
更新日期:2008-09-02 00:00:00
abstract::Natural killer-22 (NK-22) cells are a human NK cell subset situated in mucosal-associated lymphoid tissues that specialize in IL-22 secretion in response to IL-23. Here we investigated the cytokine requirements for NK-22 cell expansion. IL-7 maintained the survival of NK-22 cells and IL-22 production in response to IL...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1005641107
更新日期:2010-06-15 00:00:00
abstract::An in vitro system for replication of lambda dv plasmid DNA has been constructed. This system consists of an ammonium sulfate fraction from Escherichia coli extract, exogenously added purified lambda O and P proteins, and lambda dv DNA in closed circular form. More than 85% of the added template DNA replicated semicon...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.24.7639
更新日期:1982-12-01 00:00:00
abstract::The importance of dystrophin and its associated proteins in normal muscle function is now well established. Many of these proteins are expressed in nonmuscle tissues, particularly the brain. Here we describe the characterization of beta-dystrobrevin, a dystrophin-related protein that is abundantly expressed in brain a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.1.241
更新日期:1998-01-06 00:00:00
abstract::Human papillomavirus type 18 (HPV-18) infects genital squamous epithelium and is an etiological agent of cervical cancer. Cell-type-specific expression of HPV-18 is directed by the region upstream of the viral early genes that contains a transcriptional enhancer whose function is dependent solely on cellular factors. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.20.9102
更新日期:1991-10-15 00:00:00
abstract::Most proteins are in equilibrium with partially and globally unfolded conformations. In contrast, kinetically stable proteins (KSPs) are trapped by an energy barrier in a specific state, unable to transiently sample other conformations. Among many potential roles, it appears that kinetic stability (KS) is a feature us...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0705417104
更新日期:2007-10-30 00:00:00
abstract::Residues important in the interaction between the 23-residue transmembrane (TM) domains of the integrin alpha(IIb)- and beta(3)-subunits were identified by mutating each non-Leu residue to Leu. Leu substitutions of alpha(IIb) at G972, G976, and T981, and of beta(3) at I693 and G708, increased ligand binding. Substitut...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0409440102
更新日期:2005-03-08 00:00:00
abstract::Antagonists of growth hormone-releasing hormone (GHRH) inhibit the proliferation of various human cancers in vitro and in vivo by mechanisms that include apparent direct effects through specific binding sites expressed on tumors and that differ from pituitary human GHRH (hGHRH) receptors. In this study, GHRH antagonis...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.180313097
更新日期:2000-09-12 00:00:00
abstract::Container-shaped molecules provide structured environments that impart geometric bounds on the motions and conformations of smaller molecular occupants. Moreover, they provide "solvation" that is constrained in time and space. When inwardly directed functional groups are present, they can interact chemically with the ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.0501731102
更新日期:2005-08-02 00:00:00
abstract::Immigration and demographic change have become highly salient in American politics, partly because of the 2016 campaign of Donald Trump. Previous research indicates that local influxes of immigrants or unfamiliar ethnic groups can generate threatened responses, but has either focused on nonelectoral outcomes or analyz...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1909202116
更新日期:2019-12-10 00:00:00
abstract::Deletion of 5 residues (Delta5) from the central cytoplasmic loop of the lactose permease of Escherichia coli has no significant effect on expression or activity, whereas Delta12 leads to increased rates of permease turnover after membrane insertion and decreased transport activity, and Delta20 abolishes insertion and...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.140224497
更新日期:2000-08-01 00:00:00
abstract::3-Hydroxykynurenine (3-HK) is a tryptophan metabolite whose level in the brain is markedly elevated under several pathological conditions, including Huntington disease and human immunodeficiency virus infection. Here we demonstrate that micromolar concentrations (1-100 microM) of 3-HK cause cell death in primary neuro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.22.12553
更新日期:1996-10-29 00:00:00
abstract::The gene IL-3 encodes interleukin 3, a hematopoietic colony-stimulating factor (CSF) that is capable of supporting the proliferation of a broad range of hematopoietic cell types. By using somatic cell hybrids and in situ chromosomal hybridization, we localized this gene to human chromosome 5 at bands q23-31, a chromos...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.16.5913
更新日期:1987-08-01 00:00:00
abstract::Aphids maintain mutualistic symbioses involving consortia of coinherited organisms. All possess a primary endosymbiont, Buchnera, which compensates for dietary deficiencies; many also contain secondary symbionts, such as Hamiltonella defensa, which confers defense against natural enemies. Genome sequences of uncultiva...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0507029102
更新日期:2005-11-22 00:00:00