Bio-Med Roundup July 2006 

This month in Bio-Med Roundup:  
  • Vagin et al . and Lau et al . reported the initial characterization of a third putative RNA silencing pathway in animals.
  • Roche et al . and Heldwein et al. showed that glycoproteins from two different viruses share the same novel structure.
  • Metz et al . showed that mast cells can help protect mice from the effects of toxic snake and bee venoms.
  • Reith et al. found that soil bacteria contribute to the formation of gold grains and nuggets.

Jump to:
Cell/Developmental Biology
Medicine
Microbiology
Structural Biology
Molecular Biology
Plant Science
Neuroscience/Psychology



This month’s Bio-Med Roundup is sponsored by Polyplus-transfection
Polyplus’ INTERFERinTM siRNA transfection reagent achieves over 90 % silencing efficiency at 1 nM siRNA in a wide variety of cells with excellent viability. Using low siRNA concentrations avoids unwanted toxic and off-target effects. INTERFERinTM is ready to use and the transfection protocol is simple. It is compatible with serum and antibiotics. For more information, please visit INTERFERinTM siRNA transfection reagent page and ask for a trial size.


CELL/DEVELOPMENTAL BIOLOGY

Decay of Endoplasmic Reticulum–Localized mRNAs During the Unfolded Protein Response ( 7 July 2006 )
J. Hollien and J. S. Weissman
When stressed, cells selectively degrade those messenger RNAs that encode secretory proteins, preventing overloading of the endoplasmic reticulum.
http://www.sciencemag.org/cgi/content/abstract/313/5783/104
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5783/52

Polo-Like Kinase Cdc5 Controls the Local Activation of Rho1 to Promote Cytokinesis (
7 July 2006 )
S. Yoshida, K. Kono, D. M. Lowery, S. Bartolini, M. B. Yaffe, Y. Ohya, D. Pellman
In yeast, regulatory enzymes work together to activate actin in the contractile ring, causing it to constrict and separate daughter cells during cell division.
http://www.sciencemag.org/cgi/content/abstract/313/5783/108

Hox Control of Organ Size by Regulation of Morphogen Production and Mobility (
7 July 2006 )
M. A. Crickmore and R. S. Mann
The small size of the Drosophila hindwing results from spatial restriction of the critical morphogen by binding proteins not expressed in the larger forewing.
http://www.sciencemag.org/cgi/content/abstract/313/5783/63
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5783/50

Arginylation of
β-Actin Regulates Actin Cytoskeleton and Cell Motility ( 14 July 2006 )
M. Karakozova, M. Kozak, C. C. L. Wong, A. O. Bailey, J. R. Yates, III, A. Mogilner, H. Zebroski, A. Kashina
Addition of an amino acid to actin modulates its properties, affecting (for example) its localization and the formation of lamellae in motile cells.
http://www.sciencemag.org/cgi/content/abstract/313/5784/192
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5784/180

Ca 2+ Entry Through Plasma Membrane IP3 Receptors (
14 July 2006 )
O. Dellis, S. G. Dedos, S. C. Tovey, Taufiq-Ur-Rahman, S. J. Dubel, C. W. Taylor
Just two copies of an ion-conducting receptor in the membrane of immune cells can apparently contribute significantly to calcium entry after antigen stimulation.
http://www.sciencemag.org/cgi/content/abstract/313/5784/229
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5784/183

Receptor Activation Alters Inner Surface Potential During Phagocytosis (
21 July 2006 )
T. Yeung, M. Terebiznik, L. Yu, J. Silvius, W. M. Abidi, M. Philips, T. Levine, A. Kapus, S. Grinstein
As macrophages ingest material, changes in their phospholipids alter the charge on the membrane surface, releasing signaling molecules retained by electrostatic interactions.
http://www.sciencemag.org/cgi/content/abstract/313/5785/347

MC1R Germline Variants Confer Risk for BRAF -Mutant Melanoma (
28 July 2006 )
M. T. Landi, J. Bauer, R. M. Pfeiffer, D. E. Elder, B. Hulley, P. Minghetti, D. Calista, P. A. Kanetsky, D. Pinkel, B. C. Bastian
Individuals carrying certain normal variants of a receptor for melanocortin have a much greater risk of developing a type of melanoma that is not caused by sun damage.
http://www.sciencemag.org/cgi/content/abstract/313/5786/521

Mast Cells Can Enhance Resistance to Snake and Honeybee Venoms (
28 July 2006 )
M. Metz, A. M. Piliponsky, C.-C. Chen, V. Lammel, M. Åbrink, G. Pejler, M. Tsai, S. J. Galli
Immune cells responsible for allergic reactions help protect mice from the effects of snake and bee venoms.
http://www.sciencemag.org/cgi/content/abstract/313/5786/526

Multiple Phosphorylation Sites Confer Reproducibility of the Rod’s Single-Photon Responses (
28 July 2006 )
T. Doan, A. Mendez, P. B. Detwiler, J. Chen, F. Rieke
One photon produces a highly reproducible response in the light sensor rhodopsin by triggering inhibitory phosphorylations.
http://www.sciencemag.org/cgi/content/abstract/313/5786/530

Activated Signal Transduction Kinases Frequently Occupy Target Genes (
28 July 2006 )
D. K. Pokholok, J. Zeitlinger, N. M. Hannett, D. B. Reynolds, R. A. Young
Signaling molecules such as protein kinases that regulate gene expression are unexpectedly bound to the transcribed regions of their target genes.
http://www.sciencemag.org/cgi/content/abstract/313/5786/533
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5786/449




MEDICINE

Presymptomatic Detection of Prions in Blood (
7 July 2006 )
P. Saa, J. Castilla, C. Soto
Infectious prions can be detected in the blood of infected hamsters before they exhibit any signs of illness.
http://www.sciencemag.org/cgi/content/abstract/313/5783/92

Prion-Induced Amyloid Heart Disease with High Blood Infectivity in Transgenic Mice (
7 July 2006 )
M. J. Trifilo, T. Yajima, Y. Gu, N. Dalton, K. L. Peterson, R. E. Race, K. Meade-White, J. L. Portis, E. Masliah, K. U. Knowlton et al.
Transgenic mice with a soluble form of the prion protein develop heart disease and high blood levels after infection with the scrapie prion.
http://www.sciencemag.org/cgi/content/abstract/313/5783/94

α-Synuclein Blocks ER-Golgi Traffic and Rab1 Rescues Neuron Loss in Parkinson’s Models (
21 July 2006 )
A. A. Cooper, A. D. Gitler, A. Cashikar, C. M. Haynes, K. J. Hill, B. Bhullar, K. Liu, K. Xu, K. E. Strathearn, F. Liu et al.
An abnormal protein that causes a defect in membrane trafficking may account for some of the pathology of Parkinson’s disease.
http://www.sciencemag.org/cgi/content/abstract/313/5785/324

Chimpanzee Reservoirs of Pandemic and Nonpandemic HIV-1 (
28 July 2006 )
B. F. Keele, F. Van Heuverswyn, Y. Li, E. Bailes, J. Takehisa, M. L. Santiago, F. Bibollet-Ruche, Y. Chen, L. V. Wain, F. Liegeois et al.
The origins of HIV are traced to specific reservoir populations of wild chimpanzees.
http://www.sciencemag.org/cgi/content/abstract/313/5786/523




MICROBIOLOGY

Antibiotic Stress Induces Genetic Transformability in the Human Pathogen Streptococcus pneumoniae (
7 July 2006 )
M. Prudhomme, L. Attaiech, G. Sanchez, B. Martin, J.-P. Claverys
In addition to selecting for resistance, antibiotic treatment of Streptococcus bacteria stimulates exchange of genetic material among individuals, further enhancing resistance and virulence.
http://www.sciencemag.org/cgi/content/abstract/313/5783/89

Biomineralization of Gold: Biofilms on Bacterioform Gold (
14 July 2006 )
F. Reith, S. L. Rogers, D. C. McPhail, D. Webb
Bacteria that can cause precipitation of gold are found coating many secondary gold grains from Australian mines.
http://www.sciencemag.org/cgi/content/abstract/313/5784/233

Selective Silencing of Foreign DNA with Low GC Content by the H-NS Protein in Salmonella (
14 July 2006 )
W. W. Navarre, S. Porwollik, Y. Wang, M. McClelland, H. Rosen, S. J. Libby, F. C. Fang
Bacteria can recognize and silence invading foreign DNA by virtue of its lower overall GC content.
http://www.sciencemag.org/cgi/content/abstract/313/5784/236

Aneuploidy and Isochromosome Formation in Drug-Resistant Candida albicans (
21 July 2006 )
A. Selmecki, A. Forche, J. Berman
A fungal pathogen develops resistance to antifungal azole drugs by assembling an isochromosome consisting of extra copies of the left arm of chromosome 5.
http://www.sciencemag.org/cgi/content/abstract/313/5785/367

Genome of Rice Cluster I Archaea--the Key Methane Producers in the Rice Rhizosphere (
21 July 2006 )
C. Erkel, M. Kube, R. Reinhardt, W. Liesack
A methane-producing Archaea from rice fields can perform assimilatory sulfate reduction and is surprisingly tolerant of oxygen, explaining its ecological success.
http://www.sciencemag.org/cgi/content/abstract/313/5785/370




STRUCTURAL BIOLOGY

Crystal Structure of the Low-pH Form of the Vesicular Stomatitis Virus Glycoprotein G (
14 July 2006 )
S. Roche, S. Bressanelli, F. A. Rey, Y. Gaudin
Glycoprotein G from an RNA virus shows a reversible conformational change upon fusion with the host cell and is homologous to glycoprotein gB from herpesvirus.
http://www.sciencemag.org/cgi/content/abstract/313/5784/187
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5784/177

Crystal Structure of Glycoprotein B from Herpes Simplex Virus 1 (
14 July 2006 )
E. E. Heldwein, H. Lou, F. C. Bender, G. H. Cohen, R. J. Eisenberg, S. C. Harrison
Glycoprotein B from herpesvirus, a conserved component of the cell entry apparatus, has features of fusion proteins and is homologous to protein G from vesicular stomatitis virus.
http://www.sciencemag.org/cgi/content/abstract/313/5784/217
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5784/177

Crystal Structure of a Divalent Metal Ion Transporter CorA at 2.9 Angstrom Resolution (
21 July 2006 )
S. Eshaghi, D. Niegowski, A. Kohl, D. M. Molina, S. A. Lesley, P. Nordlund
A transporter for divalent metal ions has a long narrow pore with potential selectivity filters at both ends and two metal binding sites that probably regulate transport.
http://www.sciencemag.org/cgi/content/abstract/313/5785/354

Structure of the Vesicular Stomatitis Virus Nucleoprotein-RNA Complex (
21 July 2006 )
T. J. Green, X. Zhang, G. W. Wertz, M. Luo
http://www.sciencemag.org/cgi/content/abstract/313/5785/357

Crystal Structure of the Rabies Virus Nucleoprotein-RNA Complex (
21 July 2006 )
A. A. V. Albertini, A. K. Wernimont, T. Muziol, R. B. G. Ravelli, C. R. Clapier, G. Schoehn, W. Weissenhorn, R. W. H. Ruigrok
http://www.sciencemag.org/cgi/content/abstract/313/5785/360
Two viruses sequester their RNA genome within nucleoprotein to protect it from the host immune response but can expose it for transcription and replication.




MOLECULAR BIOLOGY

A Distinct Small RNA Pathway Silences Selfish Genetic Elements in the Germline (
21 July 2006 )
V. V. Vagin, A. Sigova, C. Li, H. Seitz, V. Gvozdev, P. D. Zamore
A third class of small RNAs, distinct from miRNAs and siRNAs, silences endogenous selfish genetic elements and repetitive sequences in animals.
http://www.sciencemag.org/cgi/content/abstract/313/5785/320
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5785/305

Characterization of the piRNA Complex from Rat Testes (
21 July 2006 )
N. C. Lau, A. G. Seto, J. Kim, S. Kuramochi-Miyagawa, T. Nakano, D. P. Bartel, R. E. Kingston
A class of noncoding RNAs, about eight nucleotides longer than siRNA or miRNA, assembles into complexes that probably participate in gene silencing.
http://www.sciencemag.org/cgi/content/abstract/313/5785/363
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5785/305

Transcript-Assisted Transcriptional Proofreading (
28 July 2006 )
N. Zenkin, Y. Yuzenkova, K. Severinov
During transcription, misincorporated nucleotides participate in their own removal by providing active groups and coordination bonds.
http://www.sciencemag.org/cgi/content/abstract/313/5786/496
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5786/447

Nuclear Gene Indicates Coat-Color Polymorphism in Mammoths (
7 July 2006 )
H. Römpler, N. Rohland, C. Lalueza-Fox, E. Willerslev, T. Kuznetsova, G. Rabeder, J. Bertranpetit, T. Schöneberg, M. Hofreiter
The sequence of the melanocortin receptor gene from mammoth DNA indicates the presence of two alleles, which may have specified light or dark hair coloration.
http://www.sciencemag.org/cgi/content/abstract/313/5783/62

A Single Amino Acid Mutation Contributes to Adaptive Beach Mouse Color Pattern (
7 July 2006 )
H. E. Hoekstra, R. J. Hirschmann, R. A. Bundey, P. A. Insel, J. P. Crossland
An allele of the melanocortin receptor found in mice adapted for living on beach sand is responsible for their light fur.
http://www.sciencemag.org/cgi/content/abstract/313/5783/101




PLANT SCIENCE

Hierarchical Action and Inhibition of Plant Dicer-Like Proteins in Antiviral Defense (
7 July 2006 )
A. Deleris, J. Gallego-Bartolome, J. Bao, K. D. Kasschau, J. C. Carrington, O. Voinnet
RNA silencing blocks infection and long-distance transport of infecting viruses in Arabidopsis .
http://www.sciencemag.org/cgi/content/abstract/313/5783/68
See related Perspective at http://www.sciencemag.org/cgi/content/summary/313/5783/54

A Bacterial Virulence Protein Suppresses Host Innate Immunity to Cause Plant Disease (
14 July 2006 )
K. Nomura, S. DebRoy, Y. H. Lee, N. Pumplin, J. Jones, S. Y. He
A bacterial plant pathogen co-opts the target cell’s own proteasome to degrade a defensive immunity protein used by the plant.
http://www.sciencemag.org/cgi/content/abstract/313/5784/220

Transcriptional Repression Distinguishes Somatic from Germ Cell Lineages in a Plant (
28 July 2006 )
F. Haerizadeh, M. B. Singh, P. L. Bhalla
Plant cells differentiate into sperm when they lack a repressive transcription factor that suppresses this differentiation in other cells.
http://www.sciencemag.org/cgi/content/abstract/313/5786/496




NEUROSCIENCE/PSYCHOLOGY

Teaching in Wild Meerkats (
14 July 2006 )
A. Thornton and K. McAuliffe
Adult wild meerkats train younger meerkats to kill prey by opportunity teaching, in which they provide pupils with the chance to practice skills in an interactive process.
http://www.sciencemag.org/cgi/content/abstract/313/5784/227

Cortical 5-HT2A Receptor Signaling Modulates Anxiety-Like Behaviors in Mice (
28 July 2006 )
N. V. Weisstaub, M. Zhou, A. Lira, E. Lambe, J. González-Maeso, J.-P. Hornung, E. Sibille, M. Underwood, S. Itohara, W. T. Dauer et al.
When one type of serotonin receptor is genetically removed from the cortex of mice, they show reduced anxiety.
http://www.sciencemag.org/cgi/content/abstract/313/5786/536


This month’s Bio-Med Roundup is sponsored by Polyplus-transfection
Polyplus’ INTERFERinTM siRNA transfection reagent achieves over 90 % silencing efficiency at 1 nM siRNA in a wide variety of cells with excellent viability. Using low siRNA concentrations avoids unwanted toxic and off-target effects. INTERFERinTM is ready to use and the transfection protocol is simple. It is compatible with serum and antibiotics. For more information, please visit INTERFERinTM siRNA transfection reagent page and ask for a trial size.