Bio-Med Roundup

This month in Bio-Med Roundup:
  • DeWan et al . and Yang et al . identified a single nucleotide polymorphism in the HTRA1 gene that confers increased susceptibility to age-related macular degeneration.
  • Conti et al . showed that transgenic mice engineered to have a 0.5 ° C reduction in their core body temperature live about 15% longer than their wild-type littermates.
  • Revyakin et al . and Kapanidis et al. described a DNA scrunching mechanism involved in the initial steps of transcription.
  • Roumagnac et al. traced the evolutionary history of Salmonella Typhi, the bacterial strain that causes typhoid fever.
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This month’s Bio-Med Roundup is sponsored by: Eppendorf
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centrifuges; all in one space-saving unit.
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NEUROSCIENCE/PSYCHOLOGY

Protrudin Induces Neurite Formation by Directional Membrane Trafficking ( 3 November 2006 )
M. Shirane and K. I. Nakayama
Complete free-energy landscapes for folding single DNA hairpins have been determined experimentally and agree well with theoretical calculations.

Diminishing Reciprocal Fairness by Disrupting the Right Prefrontal Cortex ( 3 November 2006 )
D. Knoch, A. Pascual-Leone, K. Meyer, V. Treyer, E. Fehr
Inhibition of a high-level brain region reduces an individual’s ability to suppress selfish desires and produce generous acts.

The Polarity Protein Par-3 Directly Interacts with p75NTR to Regulate Myelination ( 3 November 2006 )
J. R. Chan, C. Jolicoeur, J. Yamauchi, J. Elliott, J. P. Fawcett, B. K. Ng, M. Cayouette
A cell polarity protein aids myelin formation at the junction between certain glial cells and axons by recruiting a growth factor receptor.

The Psychological Consequences of Money ( 17 November 2006 )
K. D. Vohs, N. L. Mead, M. R. Goode
In a laboratory experiment, individuals with money are less likely to seek help or offer assistance to other people.
See related Perspective

Predictive Codes for Forthcoming Perception in the Frontal Cortex ( 24 November 2006 )
C. Summerfield, T. Egner, M. Greene, E. Koechlin, J. Mangels, J. Hirsch
Functional brain imaging reveals that, as individuals visually identify objects, neural activity in the frontal cortex influences activity in the visual cortex.



GENETICS

Accelerated Evolution of Conserved Noncoding Sequences in Humans ( 3 November 2006 )
S. Prabhakar, J. P. Noonan, S. Pääbo, E. M. Rubin
The human genome contains conserved noncoding sequences that have evolved quickly and are located near neuronal genes, suggesting a role in cognition.

Human Hair Growth Deficiency Is Linked to a Genetic Defect in the Phospholipase Gene LIPH ( 10 November 2006 )
A. Kazantseva, A. Goltsov, R. Zinchenko, A. P. Grigorenko, A. V. Abrukova, Y. K. Moliaka, A. G. Kirillov, Z. Guo, S. Lyle, E. K. Ginter, E. I. Rogaev
Families with an inherited form of hair loss carry a defective enzyme that disrupts lipid signaling and thus provides a potential therapeutic target.

HTRA1 Promoter Polymorphism in Wet Age-Related Macular Degeneration( 10 November 2006 )
A. DeWan, M. Liu, S. Hartman, S. S. Zhang, D. T. L. Liu, C. Zhao, P. O. S. Tam, W. M. Chan, D. S. C. Lam, M. Snyder et al.

A Variant of the HTRA1 Gene Increases Susceptibility to Age-Related Macular Degeneration ( 10 November 2006 )
Z. Yang, N. J. Camp, H. Sun, Z. Tong, D. Gibbs, D. J. Cameron, H. Chen, Y. Zhao, E. Pearson, X. Li, J. Chien et al.
People who have one of the normal variants of a protein-degrading enzyme are at increased risk of developing an aggressive form of age-related macular degeneration.

Sequencing and Analysis of Neanderthal Genomic DNA ( 17 November 2006 )
J. P. Noonan, G. Coop, S. Kudaravalli, D. Smith, J. Krause, J. Alessi, F. Chen, D. Platt, S. Pääbo, J. K. Pritchard, E. M. Rubin
The sequences of DNA fragments from Neanderthal bones date the divergence of humans and Neanderthals to about 370,000 years ago.

Two Dobzhansky-Muller Genes Interact to Cause Hybrid Lethality in Drosophila ( 24 November 2006 )
N. J. Brideau, H. A. Flores, J. Wang, S. Maheshwari, X. Wang, D. A. Barbash
Sterility in the hybrid offspring of two fruit fly species is caused by a pair of interacting genes, one of which has been positively selected.



BIOCHEMISTRY

Where Water Is Oxidized to Dioxygen: Structure of the Photosynthetic Mn4 Ca Cluster ( 3 November 2006 )
J. Yano, J. Kern, K. Sauer, M. J. Latimer, Y. Pushkar, J. Biesiadka, B. Loll, W. Saenger, J. Messinger, A. Zouni, V. K. Yachandra
X-ray absorption spectrometry and available crystal structures begin to resolve the structure for the metal cluster that catalyzes oxidation of water during photosynthesis.

Direct Measurement of the Full, Sequence-Dependent Folding Landscape of a Nucleic Acid ( 10 November 2006 )
M. T. Woodside, P. C. Anthony, W. M. Behnke-Parks, K. Larizadeh, D. Herschlag, S. M. Block
Complete free-energy landscapes for folding single DNA hairpins have been determined experimentally and agree well with theoretical calculations.

Ion Selectivity in a Semisynthetic K + Channel Locked in the Conductive Conformation ( 10 November 2006 )
F. I. Valiyaveetil, M. Leonetti, T. W. Muir, R. MacKinnon
A mutant potassium channel stuck in the open position still conducts K + but not Na + , indicating that its conformation and the presence of K+ in the pore confer selectivity.

Abortive Initiation and Productive Initiation by RNA Polymerase Involve DNA Scrunching ( 17 November 2006 )
A. Revyakin, C. Liu, R. H. Ebright, T. R. Strick

Initial Transcription by RNA Polymerase Proceeds Through a DNA-Scrunching Mechanism ( 17 November 2006 )
A. N. Kapanidis, E. Margeat, S. O. Ho, E. Kortkhonjia, S. Weiss, R. H. Ebright
RNA polymerase bound to DNA begins transcription by pulling downstream DNA into itself to form a scrunched intermediate that provides the force for subsequent steps.
See related Perspective

N-Linked Glycosylation of Folded Proteins by the Bacterial Oligosaccharyltransferase ( 17 November 2006 )
M. Kowarik, S. Numao, M. F. Feldman, B. L. Schulz, N. Callewaert, E. Kiermaier, I. Catrein, M. Aebi
Bacteria can add sugars to proteins after the latter have folded, whereas eukaryotic cells do so during the protein folding process.



PHYSIOLOGY

Transgenic Mice with a Reduced Core Body Temperature Have an Increased Life Span ( 3 November 2006 )
B. Conti, M. Sanchez-Alavez, R. Winsky-Sommerer, M. C. Morale, J. Lucero, S. Brownell, V. Fabre, S. Huitron-Resendiz, S. Henriksen, E. P. Zorrilla et al.
Transgenic mice engineered to have a 0.5°C reduction in their core body temperature live about 15 percent longer than their wild-type littermates.
See related Perspective

Dissecting the Functions of the Mammalian Clock Protein BMAL1 by Tissue-Specific Rescue in Mice ( 24 November 2006 )
E. L. McDearmon, K. N. Patel, C. H. Ko, J. A. Walisser, A. C. Schook, J. L. Chong, L. D. Wilsbacher, E. J. Song, H.-K. Hong, C. A. Bradfield, J. S. Takahashi
A transcription factor required in the mouse brain for producing circadian rhythms also acts in muscle to control the animals’ activity and body weight.



MEDICINE

New Strategies for the Elimination of Polio from India ( 17 November 2006 )
N. C. Grassly, C. Fraser, J. Wenger, J. M. Deshpande, R. W. Sutter, D. L. Heymann, R. B. Aylward
Use of monovalent vaccines may eliminate polio from areas where poor sanitation and high population density facilitate transmission and interfere with vaccine efficacy.

A Bacterial Protein Enhances the Release and Efficacy of Liposomal Cancer Drugs ( 24 November 2006 )
I. Cheong, X. Huang, C. Bettegowda, L. A. Diaz, Jr., K. W. Kinzler, S. Zhou, B. Vogelstein
A lipid-cleaving enzyme from a bacterium that selectively infects tumors can cause the tumor-specific release of chemotherapeutic drugs carried by liposomes.



MICROBIOLOGY

Microtubule-Severing Activity of Shigella Is Pivotal for Intercellular Spreading ( 10 November 2006 )
S. Yoshida, Y. Handa, T. Suzuki, M. Ogawa, M. Suzuki, A. Tamai, A. Abe, E. Katayama, C. Sasakawa
Once inside a host cell, a pathogenic bacterium secretes a protein-degrading enzyme that destroys the host cytoskeleton, easing its passage and facilitating infection.
See related Perspective

5’-Triphosphate RNA Is the Ligand for RIG-I ( 10 November 2006 )
V. Hornung, J. Ellegast, S. Kim, K. Brzózka, A. Jung, H. Kato, H. Poeck, S. Akira, K.-K. Conzelmann, M. Schlee et al.

RIG-I–Mediated Antiviral Responses to Single-Stranded RNA Bearing 5’- Phosphates ( 10 November 2006 )
A. Pichlmair, O. Schulz, C. P. Tan, T. I. Näslund, P. Liljeström, F. Weber, C. Reis e Sousa
A host protein that can bind to the uncapped, single-stranded RNA genomes of many viruses triggers an antiviral response and may be a useful drug target.
See related Perspective

Evolutionary History of Salmonella Typhi ( 24 November 2006 )
R. Roumagnac, F.-X. Weill, C. Dolecek, S. Baker, S. Brisse, N. T. Chinh, T. A. H. Le, C. J. Acosta, J. Farrar, G. Dougan, M. Achtman
A large survey of the bacterial strain that causes human typhoid fever suggests that it spread globally during epidemics and persists in asymptomatic carriers.



CELL BIOLOGY

FG-Rich Repeats of Nuclear Pore Proteins Form a Three-Dimensional Meshwork with Hydrogel-Like Properties ( 3 November 2006 )
S. Frey, R. P. Richter, D. Görlich
The sieve-like mesh within the pores in the nuclear membrane is a reversible protein hydrogel, with hydrophobic bridges connecting polypeptide chains.
See related Perspective

Sara Endosomes and the Maintenance of Dpp Signaling Levels Across Mitosis ( 17 November 2006 )
C. Bökel, A. Schwabedissen, E. Entchev, O. Renaud, M. González-Gaitán
As cells divide during development, daughter cells retain the growth signals received by their parents through equal partitioning of a subpopulation of tagged intracellular vesicles.
See related Perspective

Generation of Gut-Homing IgA-Secreting B Cells by Intestinal Dendritic Cells ( 17 November 2006 )
J. R. Mora, M. Iwata, B. Eksteen, S.-Y. Song, T. Junt, B. Senman, K. L. Otipoby, A. Yokota, H. Takeuchi, P. Ricciardi-Castagnoli et al.
Immune cells in the gut are programmed by other cells in the nearby lymphoid tissue and a vitamin A–related signal to make antibodies that protect against gut pathogens.



PLANT SCIENCE

Localization of Iron in Arabidopsis Seed Requires the Vacuolar Membrane Transporter VIT1 ( 24 November 2006 )
S. A. Kim, T. Punshon, A. Lanzirotti, L. Li, J. M. Alonso, J. R. Ecker, J. Kaplan, M. L. Guerinot
A transporter sequesters iron essential for plant growth in the vacuoles of embryonic vascular cells and may provide a way to enrich the iron content of grains.
See related Perspective

A NAC Gene Regulating Senescence Improves Grain Protein, Zinc, and Iron Content in Wheat ( 24 November 2006 )
C. Uauy, A. Distelfeld, T. Fahima, A. Blechl, J. Dubcovsky
A gene in wild wheat increases its protein, zinc, and iron content and could be inserted into domesticated wheat to increase its nutritional value.
See related Perspective


This month’s Bio-Med Roundup is sponsored by: Eppendorf
One size spins all!
Our 5804/5810 Series benchtop Centrifuges satisfy your application needs by
offering remarkable throughput, high capacity and flexibility for a wide
range of sample containers. Your 3-in-1 Centrifuges. Versatile, high speed
microcentrifuges; large-capacity tube and 16-place capacity microplate
centrifuges; all in one space-saving unit.
More info >>