Proceedings of the National Academy of Sciences current issue

[This Week in PNAS] In This Issue

2008-05-06

[Commentary] Why conservation planning needs socioeconomic data

Polasky, S. — 2008-05-06

[Perspective] What's the point of the type III secretion system needle?

2008-05-06

Recent work by several groups has significantly expanded our knowledge of the structure, regulation of assembly, and function of components...

[Chemistry] Folding of a donor-acceptor polyrotaxane by using noncovalent bonding interactions

2008-05-06

Mechanically interlocked compounds, such as bistable catenanes and bistable rotaxanes, have been used to bring about actuation in nanoelectromechanical systems...

[Geology] Younger Dryas "black mats" and the Rancholabrean termination in North America

Haynes, C. V. — 2008-05-06

Of the 97 geoarchaeological sites of this study that bridge the Pleistocene-Holocene transition (last deglaciation), approximately two thirds have a...

[Geophysics] Prediction of an U2S3-type polymorph of Al2O3 at 3.7 Mbar

Umemoto, K., Wentzcovitch, R. M. — 2008-05-06

We predict by first principles a phase transition in alumina at 3.7 Mbar and room temperature from the CaIrO₃-type polymorph...

[Applied_Biological_Sciences] Mice lacking angiotensin-converting enzyme have increased energy expenditure, with reduced fat mass and improved glucose clearance

2008-05-06

In addition to its role in the storage of fat, adipose tissue acts as an endocrine organ, and it contains...

[Applied_Biological_Sciences] Cyclic distension of fibrin-based tissue constructs: Evidence of adaptation during growth of engineered connective tissue

Syedain, Z. H., Weinberg, J. S., Tranquillo, R. T. — 2008-05-06

Tissue engineering provides a means to create functional living tissue replacements. Here, we examine the effects of 3 weeks of...

[Biochemistry] Investigations of valanimycin biosynthesis: Elucidation of the role of seryl-tRNA

Garg, R. P., Qian, X. L., Alemany, L. B., Moran, S., Parry, R. J. — 2008-05-06

The antibiotic valanimycin is a naturally occurring azoxy compound produced by Streptomyces viridifaciens MG456-hF10. Precursor incorporation experiments showed that valanimycin...

[Biochemistry] Biogenesis of extracellular microfibrils: Multimerization of the fibrillin-1 C terminus into bead-like structures enables self-assembly

2008-05-06

Microfibrils are essential elements in elastic and nonelastic tissues contributing to homeostasis and growth factor regulation. Fibrillins form the core...

[Biochemistry] Hypusine modification for growth is the major function of spermidine in Saccharomyces cerevisiae polyamine auxotrophs grown in limiting spermidine

Chattopadhyay, M. K., Park, M. H., Tabor, H. — 2008-05-06

Spermidine and its derivative, hypusinated eIF5A, are essential for the growth of Saccharomyces cerevisiae. Very low concentrations of spermidine (10^–8...

[Biochemistry] Structural and mechanistic insight into the basis of mucopolysaccharidosis IIIB

Ficko-Blean, E., Stubbs, K. A., Nemirovsky, O., Vocadlo, D. J., Boraston, A. B. — 2008-05-06

Mucopolysaccharidosis III (MPS III) has four forms (A–D) that result from buildup of an improperly degraded glycosaminoglycan in lysosomes. MPS...

[Biochemistry] The crystal structure and dimerization interface of GADD45{gamma}

2008-05-06

Gadd45 proteins are recognized as tumor and autoimmune suppressors whose expression can be induced by genotoxic stresses. These proteins are...

[Biochemistry] Revealing the moonlighting role of NADP in the structure of a flavin-containing monooxygenase

Alfieri, A., Malito, E., Orru, R., Fraaije, M. W., Mattevi, A. — 2008-05-06

Flavin-containing monooxygenases (FMOs) are, after cytochromes P450, the most important monooxygenase system in humans and are involved in xenobiotics metabolism...

[Biochemistry] Design of protein function leaps by directed domain interface evolution

Huang, J., Koide, A., Makabe, K., Koide, S. — 2008-05-06

Most natural proteins performing sophisticated tasks contain multiple domains where an active site is located at the domain interface. Comparative...

[Biochemistry] Activation of PI3K/Akt and MAPK pathways regulates Myc-mediated transcription by phosphorylating and promoting the degradation of Mad1

Zhu, J., Blenis, J., Yuan, J. — 2008-05-06

Mad1, a member of the Myc/Max/Mad family, suppresses Myc-mediated transcriptional activity by competing with Myc for heterodimerization with its obligatory...

[Biophysics] From the Cover: Assembly mechanism of recombinant spider silk proteins

Rammensee, S., Slotta, U., Scheibel, T., Bausch, A. R. — 2008-05-06

Spider silk threads are formed by the irreversible aggregation of silk proteins in a spinning duct with dimensions of only...

[Biophysics] Release of hydrophobic molecules from polymer micelles into cell membranes revealed by Forster resonance energy transfer imaging

Chen, H., Kim, S., Li, L., Wang, S., Park, K., Cheng, J.-X. — 2008-05-06

It is generally assumed that polymeric micelles, upon administration into the blood stream, carry drug molecules until they are taken...

[Biophysics] Single-molecule nonequilibrium periodic Mg2+-concentration jump experiments reveal details of the early folding pathways of a large RNA

Qu, X., Smith, G. J., Lee, K. T., Sosnick, T. R., Pan, T., Scherer, N. F. — 2008-05-06

The evolution of RNA conformation with Mg²⁺ concentration ([Mg²⁺]) is typically determined from equilibrium titration measurements or nonequilibrium single [Mg²⁺]-jump...

[Cell_Biology] Mathematical modeling identifies Smad nucleocytoplasmic shuttling as a dynamic signal-interpreting system

Schmierer, B., Tournier, A. L., Bates, P. A., Hill, C. S. — 2008-05-06

TGF-β-induced Smad signal transduction from the membrane into the nucleus is not linear and unidirectional, but rather a dynamic network...

[Cell_Biology] {beta}-Arrestin-1 mediates glucagon-like peptide-1 signaling to insulin secretion in cultured pancreatic {beta} cells

2008-05-06

Glucagon-like peptide-1 (GLP-1) is a polypeptide hormone secreted from enteroendocrine L cells and potentiates glucose-dependent insulin secretion in pancreatic β...

[Cell_Biology] Bone marrow-derived circulating endothelial precursors do not contribute to vascular endothelium and are not needed for tumor growth

2008-05-06

The mechanisms by which bone marrow (BM)-derived stem cells might contribute to angiogenesis and the origin of neovascular endothelial cells...

[Cell_Biology] Rapid signal transduction in living cells is a unique feature of mechanotransduction

Na, S., Collin, O., Chowdhury, F., Tay, B., Ouyang, M., Wang, Y., Wang, N. — 2008-05-06

It is widely postulated that mechanotransduction is initiated at the local force–membrane interface by inducing local conformational changes of proteins,...

[Cell_Biology] Phenotypic transcription factors epigenetically mediate cell growth control

2008-05-06

Ribosomal RNA (rRNA) genes are down-regulated during osteogenesis, myogenesis, and adipogenesis, necessitating a mechanistic understanding of interrelationships between growth control...

[Cell_Biology] Cardiac developmental defects and eccentric right ventricular hypertrophy in cardiomyocyte focal adhesion kinase (FAK) conditional knockout mice

2008-05-06

Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that plays an important role in integrin-mediated signal transduction. To explore...

[Developmental_Biology] Pygopus activates Wingless target gene transcription through the mediator complex subunits Med12 and Med13

Carrera, I., Janody, F., Leeds, N., Duveau, F., Treisman, J. E. — 2008-05-06

Wnt target gene transcription is mediated by nuclear translocation of stabilized β-catenin, which binds to TCF and recruits Pygopus, a...

[Developmental_Biology] Functional specialization among insect chitinase family genes revealed by RNA interference

Zhu, Q., Arakane, Y., Beeman, R. W., Kramer, K. J., Muthukrishnan, S. — 2008-05-06

The biological functions of individual members of the large family of chitinase-like proteins from the red flour beetle, Tribolium castaneum...

[Developmental_Biology] ES cell pluripotency and germ-layer formation require the SWI/SNF chromatin remodeling component BAF250a

Gao, X., Tate, P., Hu, P., Tjian, R., Skarnes, W. C., Wang, Z. — 2008-05-06

ATP-dependent chromatin remodeling complexes are a notable group of epigenetic modifiers that use the energy of ATP hydrolysis to change...

[Developmental_Biology] The fetal liver is a niche for maturation of primitive erythroid cells

Isern, J., Fraser, S. T., He, Z., Baron, M. H. — 2008-05-06

Primitive erythroid cells (EryP) are the earliest differentiated cell type of the mammalian embryo. They appear in the yolk sac...

[Environmental_Sciences-BS] From the Cover: Impacts of climate warming on terrestrial ectotherms across latitude

2008-05-06

The impact of anthropogenic climate change on terrestrial organisms is often predicted to increase with latitude, in parallel with the...

[Environmental_Sciences-BS] On the protection of "protected areas"

Joppa, L. N., Loarie, S. R., Pimm, S. L. — 2008-05-06

Tropical moist forests contain the majority of terrestrial species. Human actions destroy between 1 and 2 million km² of such...

[Evolution] Noncanonical role of Hox14 revealed by its expression patterns in lamprey and shark

Kuraku, S., Takio, Y., Tamura, K., Aono, H., Meyer, A., Kuratani, S. — 2008-05-06

Hox genes are arranged in uninterrupted clusters in vertebrate genomes, and the nested patterns of their expression define spatial identities...

[Immunology] Selective targeting of ITK blocks multiple steps of HIV replication

2008-05-06

Treatment for HIV has relied on the use of antiretroviral agents that can be subject to the development of resistant...

[Immunology] Indoleamine 2,3-dioxygenase in lung dendritic cells promotes Th2 responses and allergic inflammation

2008-05-06

Indoleamine 2,3 dioxygenase (IDO) has emerged as an important mediator of immune tolerance via inhibition of Th1 responses. However, the...

[Immunology] Structural basis for NKG2A/CD94 recognition of HLA-E

Kaiser, B. K., Pizarro, J. C., Kerns, J., Strong, R. K. — 2008-05-06

The NKG2x/CD94 (x = A, C, E) natural killer-cell receptors perform an important role in immunosurveillance by binding to HLA-E...

[Medical_Sciences] High blood pressure arising from a defect in vascular function

2008-05-06

Hypertension, a major cardiovascular risk factor and cause of mortality worldwide, is thought to arise from primary renal abnormalities. However,...

[Medical_Sciences] Microdeletions are a general feature of adult and adolescent acute lymphoblastic leukemia: Unexpected similarities with pediatric disease

2008-05-06

We present here a genome-wide map of abnormalities found in diagnostic samples from 45 adults and adolescents with acute lymphoblastic...

[Medical_Sciences] Inhibition of neural crest migration underlies craniofacial dysmorphology and Hirschsprung's disease in Bardet-Biedl syndrome

2008-05-06

Facial recognition is central to the diagnosis of many syndromes, and craniofacial patterns may reflect common etiologies. In the pleiotropic...

[Medical_Sciences] Targeted deletion of the murine corneodesmosin gene delineates its essential role in skin and hair physiology

2008-05-06

Controlled proteolytic degradation of specialized junctional structures, corneodesmosomes, by epidermal proteases is an essential process for physiological desquamation of the...

[Microbiology] A polycyclic terpenoid that alleviates oxidative stress

Bosak, T., Losick, R. M., Pearson, A. — 2008-05-06

Polycyclic terpenoid lipids such as hopanes and steranes have been widely used to understand ancient biology, Earth history, and the...

[Microbiology] From the Cover: Extreme polyploidy in a large bacterium

Mendell, J. E., Clements, K. D., Choat, J. H., Angert, E. R. — 2008-05-06

Cells rely on diffusion to move metabolites and biomolecules. Diffusion is highly efficient but only over short distances. Although eukaryotic...

[Microbiology] Functional plasticity of a peroxidase allows evolution of diverse disulfide-reducing pathways

Faulkner, M. J., Veeravalli, K., Gon, S., Georgiou, G., Beckwith, J. — 2008-05-06

In Escherichia coli, the glutathione/glutaredoxin and thioredoxin pathways are essential for the reduction of cytoplasmic protein disulfide bonds, including those...

[Neuroscience] Neural correlates of mentalizing-related computations during strategic interactions in humans

Hampton, A. N., Bossaerts, P., O'Doherty, J. P. — 2008-05-06

Competing successfully against an intelligent adversary requires the ability to mentalize an opponent's state of mind to anticipate his/her future...

[Neuroscience] From the Cover: Simulation of talking faces in the human brain improves auditory speech recognition

2008-05-06

Human face-to-face communication is essentially audiovisual. Typically, people talk to us face-to-face, providing concurrent auditory and visual input. Understanding someone...

[Neuroscience] Global versus local processing of frequency-modulated tones in gerbils: An animal model of lateralized auditory cortex functions

Wetzel, W., Ohl, F. W., Scheich, H. — 2008-05-06

Hemispheric asymmetries of speech and music processing might arise from more basic specializations of left and right auditory cortex (AC)....

[Neuroscience] The effect of a serotonin-induced dissociation between spiking and perisynaptic activity on BOLD functional MRI

Rauch, A., Rainer, G., Logothetis, N. K. — 2008-05-06

The relationship of the blood oxygen-level-dependent (BOLD) signal to its underlying neuronal activity is still poorly understood. Combined physiology and...

[Neuroscience] Modular patterning of structure and function of the striatum by retinoid receptor signaling

2008-05-06

Retinoid signaling plays a crucial role in patterning rhombomeres in the hindbrain and motor neurons in the spinal cord during...

[Physiology] Anemia and splenomegaly in cGKI-deficient mice

2008-05-06

To explore the functional significance of cGMP-dependent protein kinase type I (cGKI) in the regulation of erythrocyte survival, gene-targeted mice...

[Physiology] Insulin signaling and FOXO regulate the overwintering diapause of the mosquito Culex pipiens

Sim, C., Denlinger, D. L. — 2008-05-06

The short day lengths of late summer program the mosquito Culex pipiens to enter a reproductive diapause characterized by an...

[Plant_Biology] From the Cover: Mutations in topoisomerase I as a self-resistance mechanism coevolved with the production of the anticancer alkaloid camptothecin in plants

Sirikantaramas, S., Yamazaki, M., Saito, K. — 2008-05-06

Plants produce a variety of toxic compounds, which are often used as anticancer drugs. The self-resistance mechanism to these toxic...

[errata] Correction for Assarsson et al., Kinetic analysis of a complete poxvirus transcriptome reveals an immediate-early class of genes

2008-05-06

[errata] Correction for Moglich et al., End-to-end distance distributions and intrachain diffusion constants in unfolded polypeptide chains indicate intramolecular hydrogen bond formation

2008-05-06