Spt5 Cooperates with Human Immunodeficiency Virus Type 1 Tat by Preventing Premature RNA Release at Terminator Sequences

The human immunodeficiency virus type 1 (HIV-1) Tat protein activates transcription elongation by stimulating the Tat-activated kinase (TAK/p-TEFb), a protein kinase composed of CDK9 and its cyclin partner, cyclin T1. CDK9 is able to hyperphosphorylate the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase during elongation. In addition to TAK, the transcription elongation factor Spt5 is required for the efficient activation of transcriptional elongation by Tat. To study the role of Spt5 in HIV transcription in more detail, we have developed a three-stage Tat-dependent transcription assay that permits the isolation of active preinitiation complexes, early-stage elongation complexes, and Tat-activated elongation complexes. Spt5 is recruited in the transcription complex shortly after initiation. After recruitment of Tat during elongation through the transactivation response element RNA, CDK9 is activated and induces hyperphosphorylation of Spt5 in parallel to the hyperphosphorylation of the CTD of RNA polymerase II. However, immunodepletion experiments demonstrate that Spt5 is not required for Tat-dependent activation of the kinase. Chase experiments using the Spt5-depleted extracts demonstrate that Spt5 is not required for early elongation. However, Spt5 plays an important role in late elongation by preventing the premature dissociation of RNA from the transcription complex at terminator sequences and reducing the amount of polymerase pausing at arrest sites, including bent DNA sequences. This novel biochemical function of Spt5 is analogous to the function of NusG, an elongation factor found in Escherichia coli that enhances RNA polymerase stability on templates and shows sequence similarity to Spt5

A novel chromosome segregation mechanism during female meiosis.

In a wide range of eukaryotes, chromosome segregation occurs through anaphase A, in which chromosomes move toward stationary spindle poles, anaphase B, in which chromosomes move at the same velocity as outwardly moving spindle poles, or both. In contrast, Caenorhabditis elegans female meiotic spindles initially shorten in the pole-to-pole axis such that spindle poles contact the outer kinetochore before the start of anaphase chromosome separation. Once the spindle pole-to-kinetochore contact has been made, the homologues of a 4-μm-long bivalent begin to separate. The spindle shortens an additional 0.5 μm until the chromosomes are embedded in the spindle poles. Chromosomes then separate at the same velocity as the spindle poles in an anaphase B-like movement. We conclude that the majority of meiotic chromosome movement is caused by shortening of the spindle to bring poles in contact with the chromosomes, followed by separation of chromosome-bound poles by outward sliding

Electrogenic transport and K(+) ion channel expression by the human endolymphatic sac epithelium.

The endolymphatic sac (ES) is a cystic organ that is a part of the inner ear and is connected to the cochlea and vestibule. The ES is thought to be involved in inner ear ion homeostasis and fluid volume regulation for the maintenance of hearing and balance function. Many ion channels, transporters, and exchangers have been identified in the ES luminal epithelium, mainly in animal studies, but there has been no functional study investigating ion transport using human ES tissue. We designed the first functional experiments on electrogenic transport in human ES and investigated the contribution of K(+) channels in the electrogenic transport, which has been rarely identified, even in animal studies, using electrophysiological/pharmacological and molecular biological methods. As a result, we identified functional and molecular evidence for the essential participation of K(+) channels in the electrogenic transport of human ES epithelium. The identified K(+) channels involved in the electrogenic transport were KCNN2, KCNJ14, KCNK2, and KCNK6, and the K(+) transports via those channels are thought to play an important role in the maintenance of the unique ionic milieu of the inner ear fluid

Report on the evidence for net job creation from policy support for energy efficiency and renewable energy: An appraisal of multi-sectoral modelling techniques

First paragraph: The global response in the face of man-made climate change has focused on reducing the environmental impacts of human activities. The Kyoto protocol, for instance, was the world first global agreement to reduce emissions of greenhouse gases. Much of the focus of national and international emissions reduction strategies has been on the way in which energy is produced and used in economies. Evidence suggests that much of the economic development since the industrial revolution has gone hand in hand with increased demand for and use of energy. This has typically over the last century increased demand for and use of energy from fossil fuels, such as from coal, oil and gas. The ways in which energy is produced and used can have significant impacts on greenhouse gas emissions. Solutions proposed for reducing emissions during energy production include renewable energy technologies, while energy efficiency has been proposed as the key mechanism through which energy use is reduced

Regional Policy Spillovers: The National Impact of Demand-Side Policy in an Interregional Model of the UK Economy

UK regional policy has been advocated as a means of reducing regional disparities and stimulating national growth. However, there is limited understanding of the interregional and national effects of such a policy. This paper uses an interregional computable general equilibrium model to identify the national impact of a policy-induced regional demand shock under alternative labour market closures. Our simulation results suggest that regional policy operating solely on the demand side has significant national impacts. Furthermore, the effects on the non-target region are particularly sensitive to the treatment of the regional labour market

Gauging the Relationship Between Contextual Growth and Structural Neglect

Population and land use out-migrations from urban to peripheral areas can result in non-functional, unmaintained historic structures which deteriorate to the point where removal is cheaper than removal – or demolition by neglect. The increasing rate of neglected historic structures is a growing concern. There is a need for research investigating connections between urban growth management and its effect on neglect. This paper applies Newman\u27s (2013) conceptual model of measuring neglect to Geographic Information Systems, comparing rates of neglect in historic Doylestown, Quakertown, and Bristol boroughs in Pennsylvania, USA utilizing different amounts of peripheral agricultural preservation. Comparisons are made examining descriptive statistics on existing conditions, a Polychoric correlation evaluating relationships between drivers of neglect, and a cross-comparative GIS spatial analysis. Results indicate as amounts of peripheral preserved farmlands increase, neglect can be lowered

The tripartite associations between bacteriophage, Wolbachia, and arthropods

© 2006 Bordenstein et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in PLoS Pathogens 2(2006): e43, doi:10.1371/journal.ppat.0020043.By manipulating arthropod reproduction worldwide, the heritable endosymbiont Wolbachia has spread to pandemic levels. Little is known about the microbial basis of cytoplasmic incompatibility (CI) except that bacterial densities and percentages of infected sperm cysts associate with incompatibility strength. The recent discovery of a temperate bacteriophage (WO-B) of Wolbachia containing ankyrin-encoding genes and virulence factors has led to intensifying debate that bacteriophage WO-B induces CI. However, current hypotheses have not considered the separate roles that lytic and lysogenic phage might have on bacterial fitness and phenotype. Here we describe a set of quantitative approaches to characterize phage densities and its associations with bacterial densities and CI. We enumerated genome copy number of phage WO-B and Wolbachia and CI penetrance in supergroup A- and B-infected males of the parasitoid wasp Nasonia vitripennis. We report several findings: (1) variability in CI strength for A-infected males is positively associated with bacterial densities, as expected under the bacterial density model of CI, (2) phage and bacterial densities have a significant inverse association, as expected for an active lytic infection, and (3) CI strength and phage densities are inversely related in A-infected males; similarly, males expressing incomplete CI have significantly higher phage densities than males expressing complete CI. Ultrastructural analyses indicate that approximately 12% of the A Wolbachia have phage particles, and aggregations of these particles can putatively occur outside the Wolbachia cell. Physical interactions were observed between approximately 16% of the Wolbachia cells and spermatid tails. The results support a low to moderate frequency of lytic development in Wolbachia and an overall negative density relationship between bacteriophage and Wolbachia. The findings motivate a novel phage density model of CI in which lytic phage repress Wolbachia densities and therefore reproductive parasitism. We conclude that phage, Wolbachia, and arthropods form a tripartite symbiotic association in which all three are integral to understanding the biology of this widespread endosymbiosis. Clarifying the roles of lytic and lysogenic phage development in Wolbachia biology will effectively structure inquiries into this research topic.This work was supported by grants from the NASA Astrobiology Institute (NNA04CC04A) and National Institutes of Health (R01 GM62626-01) to JJW, and by the Marine Biological Laboratory's Program in Global Infectious Diseases, funded by the Ellison Medical Foundation, to SRB

Coccidioidal Pneumonia, Phoenix, Arizona, USA, 2000–2004

A prospective evaluation identified Coccidioides spp. as frequent causes of community-acquired pneumonia

The effects of dapagliflozin on urinary metabolites in patients with type 2 diabetes

AIMS: Previously, a panel of 13 urinary metabolites linked to mitochondrial metabolism was found to be significantly reduced in patients with diabetic kidney disease and eGFR>60 ml/min/1.73m2 . The beneficial effects of SGLT-2 inhibition on cardio-renal outcomes are hypothesized in part due to improved work efficiency at the mitochondrial level. We therefore assessed the effects of the SGLT-2 inhibitor dapagliflozin, on this pre-specified panel of 13 urinary metabolites linked to mitochondrial metabolism in patients with type 2 diabetes and elevated albuminuria. MATERIALS AND METHODS: Urine and plasma samples were used from a double-blind, randomized, placebo controlled crossover trial in 31 patients with type 2 diabetes, albumin:creatinine ratio >100 mg/g, and on a stable dose of an Angiotensin Converting Enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB). Dapagliflozin or placebo treatment periods each lasted for 6 weeks, with 6 weeks wash-out in between. Urinary and plasma metabolites were quantified by gas-chromatography mass spectrometry, corrected for creatinine, and then combined into a single-valued urinary metabolite index. Fractional excretion of the metabolites was calculated. RESULTS: All 13 urinary metabolites were detectable. After 6 weeks of dapagliflozin therapy, nine of the 13 metabolites were significantly increased from baseline. The urinary metabolite index increased by 42% (95%CI: 8.5 - 85.6, p=0.01) with placebo compared to 121% (69 - 189, p<0.001) with dapaglifozin. Accordingly, the placebo-adjusted effect was 56% (11 - 118, p=0.012). In plasma, seven of the 13 metabolites were detectable, and none were modified by dapagliflozin. CONCLUSIONS: Dapagliflozin significantly increased a panel of urinary metabolites previously linked to mitochondrial metabolism. These data support the hypothesis that SGLT-2 inhibitors may improve mitochondrial function, and improvements in mitochondrial function may be a mechanism for kidney protection. Future studies of longer treatment duration and clinical outcomes are needed to confirm the clinical impact of these findings. This article is protected by copyright. All rights reserved