This month in Bio-Med Roundup:
· El-Sayed et al., Berriman et al., and Ivens et al. presented genome sequences of the tritryp parasites.
· Leutgeb et al. found that hippocampal neurons encode spatial and episodic memory by different mechanisms.
· Kujoth et al. discussed how mitochondrial mutations increase the propensity of cells to undergo apoptosis.
· Brandes et al. showed that a subset of nonconventional T cells unexpectedly act as professional antigen-presenting cells.
Jump to:
Microbiology
Neuroscience
Biochemistry
Molecular Biology
Plant Science
Genetics
Cell Biology
Genome Analysis Reveals Pili in Group B Streptococcus (1 July 2005)
P. Lauer, C. D. Rinaudo, M. Soriani, I. Margarit, D. Maione, R. Rosini, A. R. Taddei, M. Mora, R. Rappuoli, G. Grandi, J. L. Telford
Long thin pili, previously overlooked, extend from the surface of certain disease-causing bacteria and are required for pathogenesis.
http://www.sciencemag.org/cgi/content/abstract/309/5731/105
Identification of a Universal Group B Streptococcus Vaccine by Multiple Genome Screen (1 July 2005)
D. Maione, I. Margarit, C. D. Rinaudo, V. Masignani, M. Mora, M. Scarselli, H. Tettelin, C. Brettoni, E. T. Iacobini, R. Rosini et al.
A broadly specific vaccine for strep was developed by using many strains of the bacteria to select the target antigens, potentially replacing the need for multiple vaccines.
http://www.sciencemag.org/cgi/content/abstract/309/5731/148
Cell-to-Cell Transfer of Bacterial Outer Membrane Lipoproteins (1 July 2005)
E. Nudleman, D. Wall, D. Kaiser
Membrane proteins can be directly exchanged among bacteria, leading to correction of motility defects in mutant strains.
http://www.sciencemag.org/cgi/content/abstract/309/5731/125
Long-Term Monitoring of Bacteria Undergoing Programmed Population Control in a Microchemostat (1 July 2005)
F. K. Balagaddé, L. You, C. L. Hansen, F. H. Arnold, S. R. Quake
A small population of floating bacteria genetically engineered to regulate their own density can be maintained and thereby studied in a microfluidic culture system.
http://www.sciencemag.org/cgi/content/abstract/309/5731/137
Comparative Genomics of Trypanosomatid Parasitic Protozoa (15 July 2005)
N. M. El-Sayed, P. J. Myler, G. Blandin, M. Berriman, J. Crabtree, G. Aggarwal, E. Caler, H. Renauld, E. A. Worthey, C. Hertz-Fowler et al.
A comparison of the genomes of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters.
http://www.sciencemag.org/cgi/content/abstract/309/5733/404
The Genome Sequence of Trypanosoma cruzi, Etiologic Agent of Chagas Disease (15 July 2005)
N. M. El-Sayed, P. J. Myler, D. C. Bartholomeu, D. Nilsson, G. Aggarwal, A.-N. Tran, E. Ghedin, E. A. Worthey, A. L. Delcher, G. Blandin et al.
Whole-genome sequencing of T. cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs.
http://www.sciencemag.org/cgi/content/abstract/309/5733/409
The Genome Sequence of the African Trypanosome Trypanosoma brucei (15 July 2005)
M. Berriman, E. Ghedin, C. Hertz-Fowler, G. Blandin, H. Renauld, D. C. Bartholomeu, N. J. Lennard, E. Caler, N. E. Hamlin, B. Haas et al.
The 26-megabase genome of T. brucei contains 9068 predicted genes, including ~900 pseudogenes and ~1700 T. brucei–specific genes.
http://www.sciencemag.org/cgi/content/abstract/309/5733/416
The Genome of the Kinetoplastic Parasite, Leishmania major (15 July 2005)
A. C. Ivens, C. S. Peacock, E. A. Worthey, L. Murphy, G. Aggarwal, M. Berriman, E. Sisk, M.-A. Rajandream, E. Adlem, R. Aert et al.
The haploid genome of L. major has a predicted 911 RNA genes, 39 pseudogenes, and 8272 protein-coding genes, of which 36% can be ascribed a putative function.
http://www.sciencemag.org/cgi/content/abstract/309/5733/436
Apolipoprotein L-I Promotes Trypanosome Lysis by Forming Pores in Lysosomal Membranes (15 July 2005)
D. Pérez-Morga, B. Vanhollebeke, F. Paturiaux-Hanocq, D. P. Nolan, L. Lins, F. Homblé, L. Vanhamme, P. Tebabi, A. Pays, P. Poelvoorde et al.
A protein in human blood kills African trypanosomes by forming pores in the membrane of the parasite’s lysosomes.
http://www.sciencemag.org/cgi/content/abstract/309/5733/469
The Trypanosoma cruzi Proteome (15 July 2005)
J. A. Atwood III, D. B. Weatherly, T. A. Minning, B. Bundy, C. Cavola, F. R. Opperdoes, R. Orlando, R. L. Tarleton
Proteome analysis of T. cruzi,which causes Chagas’ disease, indicates that the individual stages of the parasite rely on different sources of energy.
http://www.sciencemag.org/cgi/content/abstract/309/5733/473
Complete Replication of Hepatitis C Virus in Cell Culture (22 July 2005)
B. D. Lindenbach, M. J. Evans, A. J. Syder, B. Wölk, T. L. Tellinghuisen, C. C. Liu, T. Maruyama, R. O. Hynes, D. R. Burton, J. A. McKeating, C. M. Rice
The complete replication cycle of the hepatitis C virus is reproduced in cell culture, an advance that will facilitate the development of antiviral drugs to treat infections.
http://www.sciencemag.org/cgi/content/abstract/309/5734/623
Recognition of Host Immune Activation by Pseudomonas aeruginosa (29 July 2005)
L.Wu, O. Estrada, O. Zaborina, M. Bains, L. Shen, J. E. Kohler, N. Patel, M. W. Musch, E. B. Chang, Y.-X. Fu
A pathogenic bacterium detects a defensive chemical released by the infected host and responds by expressing genes that boost its own virulence.
http://www.sciencemag.org/cgi/content/abstract/309/5735/774
A Phenylalanine Clamp Catalyzes Protein Translocation Through the Anthrax Toxin Pore (29 July 2005)
B. A. Krantz, R. A. Melnyk, S. Zhang, S. J. Juris, D. B. Lacy, Z. Wu, A. Finkelstein, R. J. Collier
A ring of phenylalanine residues within the transmembrane pore of anthrax protective antigen may facilitate protein translocation through the pore.
http://www.sciencemag.org/cgi/content/abstract/309/5735/777
See related Perspective at http://www.sciencemag.org/cgi/content/summary/309/5735/709
Crossmodal Interactions Between Olfactory and Visual Learning in Drosophila (8 July 2005)
J. Guo and A. Guo
Weak visual and olfactory stimuli act synergistically,when neither would suffice alone, to induce learning in flies.
http://www.sciencemag.org/cgi/content/abstract/309/5732/307
Evidence for Ectopic Neurotransmission at a Neuronal Synapse (15 July 2005)
J. S. Coggan, T. M. Bartol, E. Esquenazi, J. R. Stiles, S. Lamont, M. E. Martone, D. K. Berg, M. H. Ellisman, T. J. Sejnowski
Monte Carlo simulations model a synapse and its surroundings, predicting that transmitter release occurs outside the synapse itself.
http://www.sciencemag.org/cgi/content/abstract/309/5733/446
See related Perspective at http://www.sciencemag.org/cgi/content/summary/309/5733/387
Shared Cortical Anatomy for Motor Awareness and Motor Control (15 July 2005)
A. Berti, G. Bottini, M. Gandola, L. Pia, N. Smania, A. Stracciari, I. Castiglioni, G. Vallar, E. Paulesu
Patients unaware of their limb paralysis have lesions in movement-related brain areas, suggesting that the neural substrate for awareness overlaps that for movement.
http://www.sciencemag.org/cgi/content/abstract/309/5733/488
Distinct Kinetic Changes in Neurotransmitter Release After SNARE Protein Cleavage (15 July 2005)
T. Sakaba, A. Stein, R. Jahn, E. Neher
Toxins that cleave three different subunits of the vesicular fusion machinery reveal the detailed kinetics of synaptic vesicle release.
http://www.sciencemag.org/cgi/content/abstract/309/5733/491
Tau Suppression in a Neurodegenerative Mouse Model Improves Memory Function (15 July 2005)
K. SantaCruz, J. Lewis, T. Spires, J. Paulson, L. Kotilinek, M. Ingelsson, A. Guimaraes, M. DeTure, M. Ramsden, E. McGowan, C. Forster et al.
The cognitive decline seen in mice overexpressing a neurodegeneration-associated protein can be reversed by suppression of the transgene.
http://www.sciencemag.org/cgi/content/abstract/309/5733/476
Independent Codes for Spatial and Episodic Memory in Hippocampal Neuronal Ensembles (22 July 2005)
S. Leutgeb, J. K. Leutgeb, C. A. Barnes, E. I. Moser, B. L. McNaughton, M.-B. Moser
Reconciling apparently contradictory findings, hippocampal neurons are found to code for both place and events, one by changes in firing location and the other by firing rate.
http://www.sciencemag.org/cgi/content/abstract/309/5734/619
See related Perspective at http://www.sciencemag.org/cgi/content/summary/309/5734/568
Genetic Tracing Shows Segregation of Taste Neuronal Circuitries for Bitter and Sweet (29 July 2005)
M. Sugita and Y. Shiba
Bitter and sweet tastes activate separate multineuronal pathways terminating in distinct areas of the cortex.
http://www.sciencemag.org/cgi/content/abstract/309/5735/781
An Interneuronal Chemoreceptor Required for Olfactory Imprinting in C. elegans (29 July 2005)
J.-J. Remy and O. Hobert
Worms acquire a long-lasting memory of an odor while young (olfactory imprinting) through changes in a particular neuron and its expression of a membrane receptor.
http://www.sciencemag.org/cgi/content/abstract/309/5735/787
Ubiquitination on Nonlysine Residues by a Viral E3 Ubiquitin Ligase (1 July 2005)
K. Cadwell and L. Coscoy
The peptide tags that mark proteins for degradation can be attached to cysteine residues in addition to the well-known lysine attachment sites.
http://www.sciencemag.org/cgi/content/abstract/309/5731/127
Variable Control of Ets-1 DNA Binding by Multiple Phosphates in an Unstructured Region (1 July 2005)
M. A. Pufall, G. M. Lee, M. L. Nelson, H.-S. Kang, A. Velyvis, L. E. Kay, L. P. McIntosh, B. J. Graves
Variable phosphorylation on a flexible region of a transcription factor acts as a rheostat to regulate DNA binding by gradually shifting the equilibrium between high and low affinity states.
http://www.sciencemag.org/cgi/content/abstract/309/5731/142
Inferential Structure Determination (8 July 2005)
W. Rieping, M. Habeck, M. Nilges
A probabilistic method of calculating molecular structure from nuclear magnetic resonance data improves structural quality, provides an objective measure of precision, and minimizes human bias.
http://www.sciencemag.org/cgi/content/abstract/309/5732/303
Chromatic Adaptation of Photosynthetic Membranes (15 July 2005)
S. Scheuring and J. N. Sturgis
Proteins in photosynthetic membranes assemble in paracrystalline, light-harvesting domains that enlarge at low light levels.
http://www.sciencemag.org/cgi/content/abstract/309/5733/484
Crystal Structure of Human Toll-Like Receptor 3 (TLR3) Ectodomain (22 July 2005)
J. Choe, M. S. Kelker, I. A.Wilson
A Toll-like receptor, which helps the immune system sense microbes, is a large horseshoe-shaped glycoprotein that may be activated when double-stranded RNA binds to its side.
http://www.sciencemag.org/cgi/content/abstract/309/5734/581
Organization of Iron-Sulfur Clusters in Respiratory Complex I (29 July 2005)
P. Hinchliffe and L. A. Sazanov
In one of the protein complexes in the energy-generating system of cells, electrons move along an 84 A path comprising seven (of nine) metal clusters.
http://www.sciencemag.org/cgi/content/abstract/309/5735/771
tRNA Actively Shuttles Between the Nucleus and Cytosol in Yeast (1 July 2005)
A. Takano, T. Endo, T. Yoshihisa
Transfer RNAs, which form in the nucleus but are then exported for protein synthesis are transported back into the nucleus in yeast, perhaps for further quality control.
http://www.sciencemag.org/cgi/content/abstract/309/5731/140
RNA Polymerase II Is Required for RNAi-Dependent Heterochromatin Assembly (15 July 2005)
H. Kato, D. B. Goto, R. A. Martienssen, T. Urano, K. Furukawa, Y. Murakami
RNA polymerase II is required for silencing the chromosome regions around the centromere of fission yeast, a process directed by small RNAs transcribed from this region.
http://www.sciencemag.org/cgi/content/abstract/309/5733/467
Genome-Scale Identification of Nucleosome Positions in S. cerevisiae (22 July 2005)
G.-C. Yuan, Y.-Jong Liu, M. F. Dion, M. D. Slack, L. F. Wu, S. J. Altschuler, O. J. Rando
The proteins that pack DNA into the yeast nucleus are usually found next to genes, whereas large regulatory regions, which have evolved little, are left exposed.
http://www.sciencemag.org/cgi/content/abstract/309/5734/626
Regulation of X-Chromosome Counting by Tsix and Xite Sequences (29 July 2005)
J. T. Lee
Two DNA sequences are necessary for monitoring the cell’s complement of X chromosomes, so that the extra one in females can be silenced.
http://www.sciencemag.org/cgi/content/abstract/309/5735/768
Stomatal Patterning and Differentiation by Synergistic Interactions of Receptor Kinases (8 July 2005)
E. D. Shpak, J. M. McAbee, L. J. Pillitteri, K. U. Torii
A family of receptor-like kinases interacts with known receptors to control the number and distribution of stomata, the leaf pores that allow photosynthesis and respiration.
http://www.sciencemag.org/cgi/content/abstract/309/5732/290
FKF1 F-Box Protein Mediates Cyclic Degradation of a Repressor of CONSTANS in Arabidopsis (8 July 2005)
T. Imaizumi, T. F. Schultz, F. G. Harmon, L. A. Ho, S. A. Kay
As days lengthen, a repressor of a main regulatory molecule is degraded, triggering flowering in plants.
http://www.sciencemag.org/cgi/content/abstract/309/5732/293
Plant Circadian Clocks Increase Photosynthesis, Growth, Survival, and Competitive Advantage (22 July 2005)
A. N. Dodd, N. Salathia, A. Hall, E. Kévei, R. Tóth, F. Nagy, J. M. Hibberd, A. J. Millar, A. A. R. Webb
Synchrony between a plant’s intrinsic circadian clock and actual daylight cycles improves productivity and growth, perhaps accounting for the selective advantage of near-synchronous clocks.
http://www.sciencemag.org/cgi/content/abstract/309/5734/630
Cytokinin Oxidase Regulates Rice Grain Production (29 July 2005)
M. Ashikari, H. Sakakibara, S. Lin, T. Yamamoto, T. Takashi, A. Nishimura, E. R. Angeles, Q. Qian, H. Kitano, M. Matsuoka
The addition of genetic loci favoring greater seed production and shorter plants significantly improves the yield of a strain of rice.
http://www.sciencemag.org/cgi/content/abstract/309/5735/741
Genome of the Host-Cell Transforming Parasite Theileria annulata Compared with T. parva (1 July 2005)
A. Pain, H. Renauld, M. Berriman, L. Murphy, C. A. Yeats, W. Weir, A. Kerhornou, M. Aslett, R. Bishop, C. Bouchier et al.
http://www.sciencemag.org/cgi/content/abstract/309/5731/131
Genome Sequence of Theileria parva, a Bovine Pathogen That Transforms Lymphocytes (1 July 2005)
M. J. Gardner, R. Bishop, T. Shah, E. P. de Villiers, J. M. Carlton, N. Hall, Q. Ren, I. T. Paulsen, A. Pain, M. Berriman et al.
http://www.sciencemag.org/cgi/content/abstract/309/5731/134
Two parasitic protozoans that cause tick-borne disease in cattle and man unexpectedly carry no obvious genes that account for their ability to transform host lymphocytes.
See related Perspective at http://www.sciencemag.org/cgi/content/summary/309/5731/72
Mitochondrial DNA Mutations, Oxidative Stress, and Apoptosis in Mammalian Aging (15 July 2005)
G. C. Kujoth, A. Hiona, T. D. Pugh, S. Someya, K. Panzer, S. E. Wohlgemuth, T. Hofer, A. Y. Seo, R. Sullivan, W. A. Jobling et al.
Mitochondrial mutations, which accumulate with age, increase the propensity of cells to undergo apoptosis.
http://www.sciencemag.org/cgi/content/abstract/309/5733/481
Dynamics of Mammalian Chromosome Evolution Inferred from Multispecies Comparative Maps (22 July 2005)
W. J. Murphy, D. M. Larkin, A. Everts-van der Wind, G. Bourque, G. Tesler, L. Auvil, J. E. Beever, B. P. Chowdhary, F. Galibert, L. Gatzke et al.
Comparison of cat, cattle, dog, pig, and horse genomes reveals an increasing rate of chromosome
evolution since the Cretaceous and demonstrates repeated breakage at the same sites.
http://www.sciencemag.org/cgi/content/abstract/309/5734/613
Pesticide Resistance via Transposition-Mediated Adaptive Gene Truncation in Drosophila (29 July 2005)
Y. T. Aminetzach, J. M. Macpherson, D. A. Petrov
A transposable element that confers resistance to organophosphate insecticides evolved rapidly through the world’s population of fruit flies in the last 250 years.
http://www.sciencemag.org/cgi/content/abstract/309/5735/764
CELL BIOLOGY
A Magnetic Nanoprobe Technology for Detecting Molecular Interactions in Live Cells (1 July 2005)
J. Won, M. Kim, Y.-W. Yi, Y. H. Kim, N. Jung, T. K. Kim
Magnetic nanoparticles coupled to small-molecule probes are taken up by living cells and can be used to detect target proteins and activation of signaling pathways.
http://www.sciencemag.org/cgi/content/abstract/309/5731/121
The Kinesin Klp2 Mediates Polarization of Interphase Microtubules in Fission Yeast (8 July 2005)
R. E. Carazo-Salas, C. Antony, P. Nurse
Microtubules in fission yeast are oriented properly in the cell by a molecular motor, allowing the yeast cell to elongate.
http://www.sciencemag.org/cgi/content/abstract/309/5732/297
MicroRNA Expression in Zebrafish Embryonic Development (8 July 2005)
E.Wienholds, W. P. Kloosterman, E. Miska, E. Alvarez-Saavedra, E. Berezikov, E. de Bruijn, H. R. Horvitz,
S. Kauppinen, R. H. A. Plasterk
Maps of RNA expression in zebrafish embryos indicate that small noncoding RNAs participate widely in the later stages of development, controlling tissue differentiation and identity.
http://www.sciencemag.org/cgi/content/abstract/309/5732/310
Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration (8 July 2005)
M. Dezawa, H. Ishikawa, Y. Itokazu, T. Yoshihara, M. Hoshino, S. Takeda, C. Ide, Y. Nabeshima
Bone marrow cells can be directed to differentiate as muscle cells, and restore function in rodents with degenerative muscle disease.
http://www.sciencemag.org/cgi/content/abstract/309/5732/314
Professional Antigen-Presentation Function by Human ?dTCells (8 July 2005)
M. Brandes, K. Willimann, B. Moser
A subset of nonconventional T cells unexpectedly present foreign antigens and stimulate the human immune system.
http://www.sciencemag.org/cgi/content/abstract/309/5732/264
See related Perspective at http://www.sciencemag.org/cgi/content/summary/309/5732/252
A Self-Organized Vortex Array of Hydrodynamically Entrained Sperm Cells (8 July 2005)
I. H. Riedel, K. Kruse, J. Howard
Motile sperm attached by their heads to a surface beat their tails in synchrony without the application of any external synchronizing stimulus.
http://www.sciencemag.org/cgi/content/abstract/309/5732/300