This month in Bio-Med Roundup:
- He et al. showed that a mutation in the transcriptional factor DEC2 is associated with short sleep in humans and mice.
- Parker et al. reported that the short-legged phenotype of certain dog breeds is associated with a gene that arose recently by RNA-based gene duplication.
- Nurieva et al. and Johnston et al. identified the transcription factors that regulate follicular T helper cell differentiation.
- Buckler et al. and McMullen et al. investigated maize genetic diversity and found that flowering time is influenced by a large number of genetic loci with small effects.
BIOCHEMISTRY
Multiscale Mechanics of Fibrin Polymer: Gel Stretching with Protein Unfolding and Loss of Water (7 August 2009)
A. E. X. Brown et al.
Protein unfolding in stretched fibrin blood clots creates porous gels that can withstand high strains.
The C-Ala Domain Brings Together Editing and Aminoacylation Functions on One tRNA (7 August 2009)
M. Guo et al.
Many alanyl–transfer RNA synthetases contain a domain that promotes aminoacylation and editing of transfer RNA.
Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules (14 August 2009)
V. Bormuth et al.
Rupture of bonds between a molecular machine and its track creates friction, which constrains speed and efficiency.
See related Perspective.
Formation of the First Peptide Bond: The Structure of EF-P Bound to the 70S Ribosome (21 August 2009)
G. Blaha et al.
Elongation factor P binds to the ribosome so as to position the initiator transfer RNA for the first bond formation.
Structure and Mechanism of a Na+-Independent Amino Acid Transporter (21 August 2009)
P. L. Shaffer et al.
The structure of the transporter ApcT reveals common architectural principles between proton- and sodium-coupled transporters.
Structures of the Ribosome in Intermediate States of Ratcheting (21 August 2009)
W. Zhang et al.
Structures of the Escherichia coli 70S ribosome show how the large and small subunits rotate to facilitate protein synthesis.
CELL BIOLOGY
Effects of Antibiotics and a Proto-Oncogene Homolog on Destruction of Protein Translocator SecY (7 August 2009)
J. van Stelten et al.
Antibiotics promote the destruction of a vital protein translocation complex in bacteria.
See related Perspective.
Lysine Acetylation Targets Protein Complexes and Co-Regulates Major Cellular Functions (14 August 2009)
C. Choudhary et al.
A proteomic-scale analysis of protein acetylation suggests that it is an important biological regulatory mechanism.
Mechanistic Analysis of a Dynamin Effector (14 August 2009)
L. L. Lackner et al.
During mitochondrial division, a pair of proteins interacts to promote membrane scission.
ER Stress Controls Iron Metabolism Through Induction of Hepcidin (14 August 2009)
C. Vecchi et al.
Stress signals in the endoplasmic reticulum activate a transcription factor that induces expression of an iron-regulatory hormone.
Motile Cilia of Human Airway Epithelia Are Chemosensory (28 August 2009)
A. S. Shah et al.
Airway epithelia directly sense and respond to noxious substances.
See related Perspective.
The E3 Ligase TRAF6 Regulates Akt Ubiquitination and Activation (28 August 2009)
W.-L. Yang et al.
Localization and activation of signaling proteins in cancer cells are controlled by ubiquitin labeling.
See related Perspective.
NEUROSCIENCE/PSYCHOLOGY
Synaptic Integration in Tuft Dendrites of Layer 5 Pyramidal Neurons: A New Unifying Principle (7 August 2009)
M. E. Larkum et al.
Thin tuft and basal dendrites of pyramidal neurons use N-methyl-D-aspartate spikes to sum up synaptic inputs in semi-independent compartments.
Spinal Endocannabinoids and CB1 Receptors Mediate C-Fiber–Induced Heterosynaptic Pain Sensitization (7 August 2009)
A. J. Pernía-Andrade et al.
Noxious stimulation releases endocannabinoids in the spinal cord that may promote, rather than inhibit, the perception of pain.
Capuchin Monkeys Display Affiliation Toward Humans Who Imitate Them (14 August 2009)
A. Paukner et al.
The chameleon effect also operates in monkeys.
See related Perspective.
Mindblind Eyes: An Absence of Spontaneous Theory of Mind in Asperger Syndrome (14 August 2009)
A. Senju et al.
Asperger syndrome individuals do not pass a nonverbal false-belief test.
Dopamine Controls Persistence of Long-Term Memory Storage (21 August 2009)
J. I. Rossato et al.
Pharmacological and biochemical analyses reveal that dopamine determines the duration of fear memory storage.
MICROBIOLOGY/VIROLOGY
An Alternative DNA Structure Is Necessary for Pilin Antigenic Variation in Neisseria gonorrhoeae (7 August 2009)
L. A. Cahoon and H. S. Seifert
A guanine quartet DNA structure regulates antigenic variation in Neisseria gonorrheae.
Local Adaptation of Bacteriophages to Their Bacterial Hosts in Soil (14 August 2009)
M. Vos et al.
A host-parasite system indicates how ecological and evolutionary mechanisms shape the distribution of microbes in soil.
Bacteriophages Encode Factors Required for Protection in a Symbiotic Mutualism (21 August 2009)
K. M. Oliver et al.
A virus endows a bacterial symbiont of an aphid with virulence factors that kill parasitoid wasps.
Functional Characterization of the Antibiotic Resistance Reservoir in the Human Microflora (28 August 2009)
M. O. A. Sommer et al.
Large numbers of previously unidentified antibiotic resistance genes occur in gut bacteria.
IMMUNOLOGY
Bcl6 Mediates the Development of T Follicular Helper Cells (21 August 2009)
R. I. Nurieva et al.
Bcl6 and Blimp-1 Are Reciprocal and Antagonistic Regulators of T Follicular Helper Cell Differentiation (21 August 2009)
R. J. Johnston et al.
The transcription factors that regulate follicular T helper cell differentiation are identified.
See related Perspective.
Eos Mediates Foxp3-Dependent Gene Silencing in CD4+ Regulatory T Cells (28 August 2009)
F. Pan et al.
A transcription factor required for gene supression in regulatory T cells is identified.
MEDICINE/PHYSIOLOGY
The Transcriptional Repressor DEC2 Regulates Sleep Length in Mammals (14 August 2009)
Y. He et al.
Some people are genetically determined to get by with less sleep than other people.
See related Perspective.
DICER1 Mutations in Familial Pleuropulmonary Blastoma (21 August 2009)
D. A. Hill et al.
A rare form of lung cancer in children is associated with mutational disruption of an enzyme that generates small noncoding RNAs.
SDH5, a Gene Required for Flavination of Succinate Dehydrogenase, Is Mutated in Paraganglioma (28 August 2009)
H.-X. Hao et al.
Analysis of a yeast mitochondrial protein reveals a human tumor susceptibility gene.
PLANT SCIENCE
The Genetic Architecture of Maize Flowering Time (7 August 2009)
E. S. Buckler et al.
Assaying nearly a million plants reveals that maize flowering time is not controlled by a large effect at any single locus.
See related Perspective.
Genetic Properties of the Maize Nested Association Mapping Population (7 August 2009)
M. D. McMullen et al.
Outcrossing vigor in maize is most likely due to retained variability in regions around the centromeres.
See related Perspective.
Loss of Function of a Proline-Containing Protein Confers Durable Disease Resistance in Rice (21 August 2009)
S. Fukuoka et al.
Quantitative trait loci may offer a particularly durable strategy for disease resistance.
Gene-for-Gene Resistance in Striga-Cowpea Associations (28 August 2009)
J. Li and M. P. Timko
A gene thought to defend plants against infectious bacterial pathogens also supplies defense against a parasitic plant.
GENETICS
An Expressed Fgf4 Retrogene Is Associated with Breed-Defining Chondrodysplasia in Domestic Dogs (21 August 2009)
H. G. Parker et al.
The short legs that characterize certain dog breeds are associated with a gene that arose recently by RNA-based gene duplication.
See related Perspective.
On the Origin and Spread of an Adaptive Allele in Deer Mice (28 August 2009)
C. R. Linnen et al.
The light coat-color variant in deer mice is a mutation selected for its adaptive value for living in sand hills.
MOLECULAR BIOLOGY
C3PO, an Endoribonuclease That Promotes RNAi by Facilitating RISC Activation (7 August 2009)
Y. Liu et al.
Reconstitution of RNA interference reveals that Slicer activity is enhanced by the protein C3PO.