Phosphorylation and Methylation of Proteasomal Proteins of the Haloarcheon Haloferax volcanii

Proteasomes are composed of 20S core particles (CPs) of α- and β-type subunits that associate with regulatory particle AAA ATPases such as the proteasome-activating nucleotidase (PAN) complexes of archaea. In this study, the roles and additional sites of post-translational modification of proteasomes were investigated using the archaeon Haloferax volcanii as a model. Indicative of phosphorylation, phosphatase-sensitive isoforms of α1 and α2 were detected by 2-DE immunoblot. To map these and other potential sites of post-translational modification, proteasomes were purified and analyzed by tandem mass spectrometry (MS/MS). Using this approach, several phosphosites were mapped including α1 Thr147, α2 Thr13/Ser14 and PAN-A Ser340. Multiple methylation sites were also mapped to α1, thus, revealing a new type of proteasomal modification. Probing the biological role of α1 and PAN-A phosphorylation by site-directed mutagenesis revealed dominant negative phenotypes for cell viability and/or pigmentation for α1 variants including Thr147Ala, Thr158Ala and Ser58Ala. An H. volcanii Rio1p Ser/Thr kinase homolog was purified and shown to catalyze autophosphorylation and phosphotransfer to α1. The α1 variants in Thr and Ser residues that displayed dominant negative phenotypes were significantly reduced in their ability to accept phosphoryl groups from Rio1p, thus, providing an important link between cell physiology and proteasomal phosphorylation

Dispensability of Escherichia coli's latent pathways

Gene-knockout experiments on single-cell organisms have established that expression of a substantial fraction of genes is not needed for optimal growth. This problem acquired a new dimension with the recent discovery that environmental and genetic perturbations of the bacterium Escherichia coli are followed by the temporary activation of a large number of latent metabolic pathways, which suggests the hypothesis that temporarily activated reactions impact growth and hence facilitate adaptation in the presence of perturbations. Here we test this hypothesis computationally and find, surprisingly, that the availability of latent pathways consistently offers no growth advantage, and tends in fact to inhibit growth after genetic perturbations. This is shown to be true even for latent pathways with a known function in alternate conditions, thus extending the significance of this adverse effect beyond apparently nonessential genes. These findings raise the possibility that latent pathway activation is in fact derivative of another, potentially suboptimal, adaptive response

A proposal for a production line for the design and implementation of quality clothing for gymnastics in A.R.E

Gymnastics wear needs multiple specifications in terms of material and the proportion ‎of elasticity, as well as the designs in terms of players' comfort and the movements of ‎this game .In this research, an empirical research study is conducted for gymnastics ‎wear to increase its productivity rate in the national market and what are the obstacles ‎facing this industry and how to develop it and reach the international. ‎Some people see the design of gymnastics wear is a secondary idea or an aesthetic ‎form, while others see it as the fulcrum of the ‎entire development process in relation to ‎the manufacturing process and the cost ‎of production.‎So this research is based on studying everything related to these clothes from the ‎materials available in the national market, as well as suggesting 50 designs and ‎making a questionnaire to identify the ten most suitable designs for gymnastics, and ‎then implementing these designs with nationally available materials and determining ‎appropriate production methods for gymnastics wear.‎A summary of the research Findings• The local fabrics have what is suitable for the production of gymnastics wear.‎• Determination the appropriate production methods for gymnastics clothing have ‎been identified in terms of cutting, knitting and embroideries.‎The Recommendations:‎• Paying attention to the study of the Gymnastics wear of the sport of gymnastics ‎in the departments of clothes design at Arts Faculties• Paying attention to the choice of the materials of the Gymnastics wear and the ‎suitable design given their influence on the player’s movemen

Propagation of Plane Waves in Generalized Piezo-thermoelastic Medium: Comparison Of Different Theories

ABSTRACT: In this paper, a general solution for the propagation of plane waves in generalized piezo-thermoelastic medium for two-dimensional problem under the different thermoelastic theories is investigated. We have included Coupled theory (CT), Lord-Schulman (L-S) and Green-Lindsay (G-L) theories. The normal mode analysis is used to obtain the exact expressions for the considered variables. The results of the physical quantities have been illustrated graphically by comparison between (CT), (L-S) and (G-L) theories. KEYWORDS: Piezo-thermoelastic, Relaxation time, Normal mode analysis, Generalized thermoelasticity. I INTRODUCTION Piezoelectric is considered one of the basic properties of crystals, ceramics, polymers, liquid crystals and some biological tissues (e.g. bone and tendon). Recent interest in the piezoelectric materials stems from their potential applications in intelligent structural systems, and piezoelectric is currently enjoying a greatest resurgence in both fundamental research and technical applications. The theory of thermo-piezoelectric was first proposed by Mindlin Thermoelasticity theories that predict a finite speed for the propagation of thermal signals have aroused much interest in the last three decades. These theories are known as generalized thermoelasticity theories. The first generalization of the thermoelasticity theory is due to Lord and Shulman [8] who introduced the theory of generalized thermoelasticity with one relaxation time through postulating a new law of heat conduction to replace the classical Fourier' law. This law contains the heat flux vector as well as its time derivative. It contains also a new constant that acts as a relaxation time. The heat equation of this theory is of the wave-type which ensuring finite speeds of propagation of heat and elastic waves. The remaining, governing equations for this theory, namely, the equations of motion and the constitutive relations remain the same as those for the coupled and the uncoupled theories. This theory was extended by Dhaliwal and Sherief [9] to general anisotropic media in the presence of heat sources. Othman [10] studied the Lord

Structural Insights into Fibronectin Type III Domain-mediated Signaling

The alternatively spliced type-III extradomain B (EIIIB) of Fibronectin (FN) is only expressed during embryogenesis, wound healing and tumorigenesis. The biological function of this domain remains unclear. We describe here the first crystal structure of the interface between alternatively-spliced domain EIIIB and its adjacent FN type-III domain 8 (FN B-8). The opened CC′ loop of EIIIB and the rotation and tilt of EIIIB domain allows good access to the FG loop of FN-8 which is normally hindered by the CC′ loop of FN-7. In addition, the AGEGIP sequence of the CC′ loop of EIIIB replaces the NGQQGN sequence of the CC′ loop of FN-7. Finally, the CC” loop of EIIIB forms an acidic groove with FN-8. These structural findings warrant future studies directed at identifying potential binding partners for FN B-8 interface, linking EIIIB to skeletal and cartilagenous development, wound healing, and tumorigenesis, respectively

Influence of the molybdenum cofactor biosynthesis on anaerobic respiration, biofilm formation and motility in Burkholderia thailandensis

types: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS.Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Research in Microbiology, 2014, Vol. 165, Issue 1, pp. 41 – 49 DOI: 10.1016/j.resmic.2013.10.009Burkholderia thailandensis is closely related to Burkholderia pseudomallei, a bacterial pathogen and the causative agent of melioidosis. B. pseudomallei can survive and persist within a hypoxic environment for up to one year and has been shown to grow anaerobically in the presence of nitrate. Currently, little is known about the role of anaerobic respiration in pathogenesis of melioidosis. Using B. thailandensis as a model, a library of 1344 transposon mutants was created to identify genes required for anaerobic nitrate respiration. One transposon mutant (CA01) was identified with an insertion in BTH_I1704 (moeA), a gene required for the molybdopterin biosynthetic pathway. This pathway is involved in the synthesis of a molybdopterin cofactor required for a variety of molybdoenzymes, including nitrate reductase. Disruption of molybdopterin biosynthesis prevented growth under anaerobic conditions, when using nitrate as the sole terminal electron acceptor. Defects in anaerobic respiration, nitrate reduction, motility and biofilm formation were observed for CA01. Mutant complementation with pDA-17:BTH_I1704 was able to restore anaerobic growth on nitrate, nitrate reductase activity and biofilm formation, but did not restore motility. This study highlights the potential importance of molybdoenzyme-dependent anaerobic respiration in the survival and virulence of B. thailandensis.BBSRC studentship (C. A. Andreae

Genetic Analysis of the Functions and Interactions of Components of the LevQRST Signal Transduction Complex of Streptococcus mutans

Transcription of the genes for a fructan hydrolase (fruA) and a fructose/mannose sugar:phosphotransferase permease (levDEFG) in Streptococcus mutans is activated by a four-component regulatory system consisting of a histidine kinase (LevS), a response regulator (LevR) and two carbohydrate-binding proteins (LevQT). The expression of the fruA and levD operons was at baseline in a levQ mutant and substantially decreased in a levT null mutant, with lower expression with the cognate inducers fructose or mannose, but slightly higher expression in glucose or galactose. A strain expressing levQ with two point mutations (E170A/F292S) did not require inducers to activate gene expression and displayed altered levD expression when growing on various carbohydrates, including cellobiose. Linker-scanning (LS) mutagenesis was used to generate three libraries of mutants of levQ, levS and levT that displayed various levels of altered substrate specificity and of fruA/levD gene expression. The data support that LevQ and LevT are intimately involved in the sensing of carbohydrate signals, and that LevQ appears to be required for the integrity of the signal transduction complex, apparently by interacting with the sensor kinase LevS

Deletion of methylglyoxal synthase gene (mgsA) increased sugar co-metabolism in ethanol-producing Escherichia coli

The use of lignocellulose as a source of sugars for bioproducts requires the development of biocatalysts that maximize product yields by fermenting mixtures of hexose and pentose sugars to completion. In this study, we implicate mgsA encoding methylglyoxal synthase (and methylglyoxal) in the modulation of sugar metabolism. Deletion of this gene (strain LY168) resulted in the co-metabolism of glucose and xylose, and accelerated the metabolism of a 5-sugar mixture (mannose, glucose, arabinose, xylose and galactose) to ethanol

Composition dependence of lithium diffusion in lithium silicide: a density functional theory study

The lithiation process of silicon was investigated by using ab initio molecular dynamics. Diffusion coefficients of Li in Li–Si alloys were calculated to be in the range between 2.08×10−9 and 3.53×10−7 cm2 s−1 at room temperature. The results showed that the Li mobility is strongly dependent on the composition of the LixSi alloys. The Li diffusivity in a LixSi alloy can be enhanced by two orders of magnitude when x is increased from 1.0 to 3.75, which can be explained by the instability of the Si network, owing to charge transfer from Li to Si

The Pseudomonas aeruginosa Transcriptome in Planktonic Cultures and Static Biofilms Using RNA Sequencing

In this study, we evaluated how gene expression differs in mature Pseudomonas aeruginosa biofilms as opposed to planktonic cells by the use of RNA sequencing technology that gives rise to both quantitative and qualitative information on the transcriptome. Although a large proportion of genes were consistently regulated in both the stationary phase and biofilm cultures as opposed to the late exponential growth phase cultures, the global biofilm gene expression pattern was clearly distinct indicating that biofilms are not just surface attached cells in stationary phase. A large amount of the genes found to be biofilm specific were involved in adaptation to microaerophilic growth conditions, repression of type three secretion and production of extracellular matrix components. Additionally, we found many small RNAs to be differentially regulated most of them similarly in stationary phase cultures and biofilms. A qualitative analysis of the RNA-seq data revealed more than 3000 putative transcriptional start sites (TSS). By the use of rapid amplification of cDNA ends (5′-RACE) we confirmed the presence of three different TSS associated with the pqsABCDE operon, two in the promoter of pqsA and one upstream of the second gene, pqsB. Taken together, this study reports the first transcriptome study on P. aeruginosa that employs RNA sequencing technology and provides insights into the quantitative and qualitative transcriptome including the expression of small RNAs in P. aeruginosa biofilms