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1. Actin, a Central Player in Cell Shape and Movement

Author:
Pollard, Thomas D.; Cooper, John A.
Source:
Science 2009 v.326 no.5957 pp. 1208-1212
ISSN:
0036-8075
Subject:
actin; biological properties and phenomena; computer simulation; mathematical models; quantitative analysis
Abstract:
... The protein actin forms filaments that provide cells with mechanical support and driving forces for movement. Actin contributes to biological processes such as sensing environmental forces, internalizing membrane vesicles, moving over surfaces, and dividing the cell in two. These cellular activities are complex; they depend on interactions of actin monomers and filaments with numerous other protei ...
DOI:
10.1126/science.1175862
PubMed:
19965462
PubMed Central:
PMC3677050

2. A High-Resolution Structure of the Pre-microRNA Nuclear Export Machinery

Author:
Okada, Chimari; Yamashita, Eiki; Lee, Soo Jae; Shibata, Satoshi; Katahira, Jun; Nakagawa, Atsushi; Yoneda, Yoshihiro; Tsukihara, Tomitake
Source:
Science 2009 v.326 no.5957 pp. 1275-1279
ISSN:
0036-8075
Subject:
X-radiation; biogenesis; guanine; guanosine triphosphate; guanosinetriphosphatase; hydrogen bonding; microRNA; nucleotide sequences; physiological transport
Abstract:
... Nuclear export of microRNAs (miRNAs) by exportin-5 (Exp-5) is an essential step in miRNA biogenesis. Here, we present the 2.9 angstrom structure of the pre-miRNA nuclear export machinery formed by pre-miRNA complexed with Exp-5 and a guanine triphosphate (GTP)-bound form of the small nuclear guanine triphosphatase (GTPase) Ran (RanGTP). The x-ray structure shows that Exp-5:RanGTP recognizes the 2- ...
DOI:
10.1126/science.1178705

3. Anatomic Demarcation of Cells: Genes to Patterns

Author:
Chang, Howard Y.
Source:
Science 2009 v.326 no.5957 pp. 1206-1207
ISSN:
0036-8075
Subject:
animals; chromatin; gene expression; genes; genomics; loci
Abstract:
... An organizing principle of the diverse cell types in multicellular organisms is their anatomic location. In turn, anatomic location is patterned by the positional identities of cells along developmental axes. Recent progress in functional genomics and chromatin biology illustrates how cells use specific gene expression programs to encode location. Dynamic chromatin states of key genes, notably the ...
DOI:
10.1126/science.1175686

4. Cell Signaling in Space and Time: Where Proteins Come Together and When They're Apart

Author:
Scott, John D.; Pawson, Tony
Source:
Science 2009 v.326 no.5957 pp. 1220-1224
ISSN:
0036-8075
Subject:
enzymes; plasma membrane; proteins; signal transduction; space and time
Abstract:
... Signal transduction can be defined as the coordinated relay of messages derived from extracellular cues to intracellular effectors. More simply put, information received on the cell surface is processed across the plasma membrane and transmitted to intracellular targets. This requires that the activators, effectors, enzymes, and substrates that respond to cellular signals come together when they n ...
DOI:
10.1126/science.1175668
PubMed:
19965465
PubMed Central:
PMC3041271

5. Climate-Driven Basin-Scale Decadal Oscillations of Oceanic Phytoplankton

Author:
Martinez, Elodie; Antoine, David; D'Ortenzio, Fabrizio; Gentili, Bernard
Source:
Science 2009 v.326 no.5957 pp. 1253-1256
ISSN:
0036-8075
Subject:
aquatic food webs; carbon dioxide; carbon dioxide fixation; chlorophyll; climate change; evolution; microalgae; photosynthesis; phytoplankton; prediction; satellites; surface water temperature
Abstract:
... Phytoplankton--the microalgae that populate the upper lit layers of the ocean--fuel the oceanic food web and affect oceanic and atmospheric carbon dioxide levels through photosynthetic carbon fixation. Here, we show that multidecadal changes in global phytoplankton abundances are related to basin-scale oscillations of the physical ocean, specifically the Pacific Decadal Oscillation and the Atlanti ...
DOI:
10.1126/science.1177012

6. Crystal Structure of a Nucleocapsid-Like Nucleoprotein-RNA Complex of Respiratory Syncytial Virus

Author:
Tawar, Rajiv G.; Duquerroy, Stéphane; Vonrhein, Clemens; Varela, Paloma F.; Damier-Piolle, Laurence; Castagné, Nathalie; MacLellan, Kirsty; Bedouelle, Hugues; Bricogne, Gérard; Bhella, David; Eléouët, Jean-François; Rey, Félix A.
Source:
Science 2009 v.326 no.5957 pp. 1279-1283
ISSN:
0036-8075
Subject:
RNA; RNA viruses; crystal structure; electron microscopy; humans; models; nucleocapsid; nucleoproteins; nucleotides; pathogens; ribonucleoproteins; vaccines; viruses
Abstract:
... The respiratory syncytial virus (RSV) is an important human pathogen, yet neither a vaccine nor effective therapies are available to treat infection. To help elucidate the replication mechanism of this RNA virus, we determined the three-dimensional (3D) crystal structure at 3.3 Å resolution of a decameric, annular ribonucleoprotein complex of the RSV nucleoprotein (N) bound to RNA. This complex mi ...
DOI:
10.1126/science.1177634

7. Crystal Structure of the Catalytic Core of an RNA-Polymerase Ribozyme

Author:
Shechner, David M.; Grant, Robert A.; Bagby, Sarah C.; Koldobskaya, Yelena; Piccirilli, Joseph A.; Bartel, David P.
Source:
Science 2009 v.326 no.5957 pp. 1271-1275
ISSN:
0036-8075
Subject:
RNA; RNA ligase (ATP); RNA replication; active sites; catalytic activity; crystal structure; cytosine; models; phosphates
Abstract:
... Primordial organisms of the putative RNA world would have required polymerase ribozymes able to replicate RNA. Known ribozymes with polymerase activity best approximating that needed for RNA replication contain at their catalytic core the class I RNA ligase, an artificial ribozyme with a catalytic rate among the fastest of known ribozymes. Here we present the 3.0 angstrom crystal structure of this ...
DOI:
10.1126/science.1174676
PubMed:
19965478
PubMed Central:
PMC3978776

8. Directed Transport of Atoms in a Hamiltonian Quantum Ratchet

Author:
Salger, Tobias; Kling, Sebastian; Hecking, Tim; Geckeler, Carsten; Morales-Molina, Luis; Weitz, Martin
Source:
Science 2009 v.326 no.5957 pp. 1241-1243
ISSN:
0036-8075
Subject:
photons; rubidium
Abstract:
... Classical ratchet potentials, which alternate a driving potential with periodic random dissipative motion, can account for the operation of biological motors. We demonstrate the operation of a quantum ratchet, which differs from classical ratchets in that dissipative processes are absent within the observation time of the system (Hamiltonian regime). An atomic rubidium Bose-Einstein condensate is ...
DOI:
10.1126/science.1179546

9. Extensive, Recent Intron Gains in Daphnia Populations

Author:
Li, Wenli; Tucker, Abraham E.; Sung, Way; Thomas, W. Kelley; Lynch, Michael
Source:
Science 2009 v.326 no.5957 pp. 1260-1262
ISSN:
0036-8075
Subject:
Daphnia pulex; alleles; exons; genetic drift; introns; loci; organisms; phylogeny
Abstract:
... Rates and mechanisms of intron gain and loss have traditionally been inferred from alignments of highly conserved genes sampled from phylogenetically distant taxa. We report a population-genomic approach that detected 24 discordant intron/exon boundaries between the whole-genome sequences of two Daphnia pulex isolates. Sequencing of presence/absence loci across a collection of D. pulex isolates an ...
DOI:
10.1126/science.1179302
PubMed:
19965475
PubMed Central:
PMC3878872

10. Formation of Compositionally Abrupt Axial Heterojunctions in Silicon-Germanium Nanowires

Author:
Wen, C.-Y.; Reuter, M.C.; Bruley, J.; Tersoff, J.; Kodambaka, S.; Stach, E.A.; Ross, F.M.
Source:
Science 2009 v.326 no.5957 pp. 1247-1250
ISSN:
0036-8075
Subject:
alloys; catalysts; droplets; growth models; image analysis; nanowires; quantum dots; silicon; solubility
Abstract:
... We have formed compositionally abrupt interfaces in silicon-germanium (Si-Ge) and Si-SiGe heterostructure nanowires by using solid aluminum-gold alloy catalyst particles rather than the conventional liquid semiconductor-metal eutectic droplets. We demonstrated single interfaces that are defect-free and close to atomically abrupt, as well as quantum dots (i.e., Ge layers tens of atomic planes thick ...
DOI:
10.1126/science.1178606

11. Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly

Author:
Mann, Michael E.; Zhang, Zhihua; Rutherford, Scott; Bradley, Raymond S.; Hughes, Malcolm K.; Shindell, Drew; Ammann, Caspar; Faluvegi, Greg; Ni, Fenbiao
Source:
Science 2009 v.326 no.5957 pp. 1256-1260
ISSN:
0036-8075
Subject:
El Nino; climate; cooling; radiative forcing; surface temperature
Abstract:
... Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This per ...
DOI:
10.1126/science.1177303

12. Haploid Genetic Screens in Human Cells Identify Host Factors Used by Pathogens

Author:
Carette, Jan E.; Guimaraes, Carla P.; Varadarajan, Malini; Park, Annie S.; Wuethrich, Irene; Godarova, Alzbeta; Kotecki, Maciej; Cochran, Brent H.; Spooner, Eric; Ploegh, Hidde L.; Brummelkamp, Thijn R.
Source:
Science 2009 v.326 no.5957 pp. 1231-1235
ISSN:
0036-8075
Subject:
biochemical pathways; chromosomes; cytotoxicity; diploidy; exotoxins; gene targeting; haploidy; human cell lines; humans; influenza; insertional mutagenesis; loss-of-function mutation; models; null alleles; pathogens; screening; yeasts
Abstract:
... Loss-of-function genetic screens in model organisms have elucidated numerous biological processes, but the diploid genome of mammalian cells has precluded large-scale gene disruption. We used insertional mutagenesis to develop a screening method to generate null alleles in a human cell line haploid for all chromosomes except chromosome 8. Using this approach, we identified host factors essential f ...
DOI:
10.1126/science.1178955

13. Impact of Genome Reduction on Bacterial Metabolism and Its Regulation

Author:
Yus, Eva; Maier, Tobias; Michalodimitrakis, Konstantinos; van Noort, Vera; Yamada, Takuji; Chen, Wei-Hua; Wodke, Judith A.H.; Güell, Marc; Martínez, Sira; Bourgeois, Ronan; Kühner, Sebastian; Raineri, Emanuele; Letunic, Ivica; Kalinina, Olga V.; Rode, Michaela; Herrmann, Richard; Gutiérrez-Gallego, Ricardo; Russell, Robert B.; Gavin, Anne-Claude; Bork, Peer; Serrano, Luis
Source:
Science 2009 v.326 no.5957 pp. 1263-1268
ISSN:
0036-8075
Subject:
Mycoplasma pneumoniae; bacteria; biomass; enzymes; gene expression; genome; metabolism; metabolites; nutrient content; nutrients; topology
Abstract:
... To understand basic principles of bacterial metabolism organization and regulation, but also the impact of genome size, we systematically studied one of the smallest bacteria, Mycoplasma pneumoniae. A manually curated metabolic network of 189 reactions catalyzed by 129 enzymes allowed the design of a defined, minimal medium with 19 essential nutrients. More than 1300 growth curves were recorded in ...
DOI:
10.1126/science.1177263

14. Induced Chromosomal Proximity and Gene Fusions in Prostate Cancer

Author:
Mani, Ram-Shankar; Tomlins, Scott A.; Callahan, Kaitlin; Ghosh, Aparna; Nyati, Mukesh K.; Varambally, Sooryanarayana; Palanisamy, Nallasivam; Chinnaiyan, Arul M.
Source:
Science 2009 v.326 no.5957 pp. 1230
ISSN:
0036-8075
Subject:
5' untranslated regions; DNA damage; disease course; fluorescence in situ hybridization; gamma radiation; gene fusion; genes; humans; loci; neoplasm cells; prostatic neoplasms; transcription (genetics); transcription factors
Abstract:
... Gene fusions play a critical role in cancer progression. The mechanisms underlying their genesis and cell type specificity are not well understood. About 50% of human prostate cancers display a gene fusion involving the 5' untranslated region of TMPRSS2, an androgen-regulated gene, and the protein-coding sequences of ERG, which encodes an erythroblast transformation-specific (ETS) transcription fa ...
DOI:
10.1126/science.1178124
PubMed:
19933109
PubMed Central:
PMC2935583

15. Proteome Organization in a Genome-Reduced Bacterium

Author:
Kühner, Sebastian; van Noort, Vera; Betts, Matthew J.; Leo-Macias, Alejandra; Batisse, Claire; Rode, Michaela; Yamada, Takuji; Maier, Tobias; Bader, Samuel; Beltran-Alvarez, Pedro; Castaño-Diez, Daniel; Chen, Wei-Hua; Devos, Damien; Güell, Marc; Norambuena, Tomas; Racke, Ines; Rybin, Vladimir; Schmidt, Alexander; Yus, Eva; Aebersold, Ruedi; Herrmann, Richard; Böttcher, Bettina; Frangakis, Achilleas S.; Russell, Robert B.; Serrano, Luis; Bork, Peer; Gavin, Anne-Claude
Source:
Science 2009 v.326 no.5957 pp. 1235-1240
ISSN:
0036-8075
Subject:
Mycoplasma pneumoniae; bacteria; data collection; electron microscopy; genome; models; multiprotein complexes; proteome; spectroscopy
Abstract:
... The genome of Mycoplasma pneumoniae is among the smallest found in self-replicating organisms. To study the basic principles of bacterial proteome organization, we used tandem affinity purification-mass spectrometry (TAP-MS) in a proteome-wide screen. The analysis revealed 62 homomultimeric and 116 heteromultimeric soluble protein complexes, of which the majority are novel. About a third of the he ...
DOI:
10.1126/science.1176343

16. Selective Phenol Hydrogenation to Cyclohexanone Over a Dual Supported Pd-Lewis Acid Catalyst

Author:
Liu, Huizhen; Jiang, Tao; Han, Buxing; Liang, Shuguang; Zhou, Yinxi
Source:
Science 2009 v.326 no.5957 pp. 1250-1252
ISSN:
0036-8075
Subject:
Lewis acids; aluminum chloride; aluminum oxide; carbon; carbon dioxide; catalysts; cyclohexanones; hydrogen; hydrogenation; nylon; palladium; phenol; solvents; spectral analysis; temperature; zeolites
Abstract:
... Cyclohexanone is an industrially important intermediate in the synthesis of materials such as nylon, but preparing it efficiently through direct hydrogenation of phenol is hindered by over-reduction to cyclohexanol. Here we report that a previously unappreciated combination of two common commercial catalysts[horizontal bar]nanoparticulate palladium (supported on carbon, alumina, or NaY zeolite) an ...
DOI:
10.1126/science.1179713

17. Subcellular mRNA Localization in Animal Cells and Why It Matters

Author:
Holt, Christine E.; Bullock, Simon L.
Source:
Science 2009 v.326 no.5957 pp. 1212-1216
ISSN:
0036-8075
Subject:
cell biology; messenger RNA; protein products
Abstract:
... Subcellular localization of messenger RNAs (mRNAs) can give precise control over where protein products are synthesized and operate. However, just 10 years ago many in the broader cell biology community would have considered this a specialized mechanism restricted to a very small fraction of transcripts. Since then, it has become clear that subcellular targeting of mRNAs is prevalent, and there is ...
DOI:
10.1126/science.1176488
PubMed:
19965463
PubMed Central:
PMC3785123

18. The Extracellular Matrix: Not Just Pretty Fibrils

Author:
Hynes, Richard O.
Source:
Science 2009 v.326 no.5957 pp. 1216-1219
ISSN:
0036-8075
Subject:
adhesion; cell adhesion; extracellular matrix; genetic disorders; growth factors; integrins; ligands; neoplasms; niches; receptors; stem cells
Abstract:
... The extracellular matrix (ECM) and ECM proteins are important in phenomena as diverse as developmental patterning, stem cell niches, cancer, and genetic diseases. The ECM has many effects beyond providing structural support. ECM proteins typically include multiple, independently folded domains whose sequences and arrangement are highly conserved. Some of these domains bind adhesion receptors such ...
DOI:
10.1126/science.1176009
PubMed:
19965464
PubMed Central:
PMC3536535

19. Transcriptome Complexity in a Genome-Reduced Bacterium

Author:
Güell, Marc; van Noort, Vera; Yus, Eva; Chen, Wei-Hua; Leigh-Bell, Justine; Michalodimitrakis, Konstantinos; Yamada, Takuji; Arumugam, Manimozhiyan; Doerks, Tobias; Kühner, Sebastian; Rode, Michaela; Suyama, Mikita; Schmidt, Sabine; Gavin, Anne-Claude; Bork, Peer; Serrano, Luis
Source:
Science 2009 v.326 no.5957 pp. 1268-1271
ISSN:
0036-8075
Subject:
Mycoplasma pneumoniae; bacteria; eukaryotic cells; non-coding RNA; operon; transcription (genetics); transcriptome; transcriptomics
Abstract:
... To study basic principles of transcriptome organization in bacteria, we analyzed one of the smallest self-replicating organisms, Mycoplasma pneumoniae. We combined strand-specific tiling arrays, complemented by transcriptome sequencing, with more than 252 spotted arrays. We detected 117 previously undescribed, mostly noncoding transcripts, 89 of them in antisense configuration to known genes. We i ...
DOI:
10.1126/science.1176951

20. Visualizing the 3D Internal Structure of Calcite Single Crystals Grown in Agarose Hydrogels

Author:
Li, Hanying; Xin, Huolin L.; Muller, David A.; Estroff, Lara A.
Source:
Science 2009 v.326 no.5957 pp. 1244-1247
ISSN:
0036-8075
Subject:
agarose; calcite; chemical composition; composite materials; crystals; hydrogels; nanofibers; polymers; tomography
Abstract:
... Single crystals are usually faceted solids with homogeneous chemical compositions. Biogenic and synthetic calcite single crystals, however, have been found to incorporate macromolecules, spurring investigations of how large molecules are distributed within the crystals without substantially disrupting the crystalline lattice. Here, electron tomography reveals how random, three-dimensional networks ...
DOI:
10.1126/science.1178583