Biochemical Investigation of the Interaction of pICln,RioK1 and COPR5 with the PRMT5–MEP50 Complex

The PRMT5–MEP50 methyltransferase complex plays a key role in various cancers and is regulated by different protein–protein interactions. Several proteins have been reported to act as adaptor proteins that recruit substrate proteins to the active site of PRMT5 for the methylation of arginine residues. To define the interaction between these adaptor proteins and PRMT5, we employed peptide truncation and mutation studies and prepared truncated protein constructs. We report the characterisation of the interface between the TIM barrel of PRMT5 and the adaptor proteins pICln, RioK1 and COPR5, and identify the consensus amino acid sequence GQF[D/E]DA[E/D] involved in binding. Protein crystallography revealed that the RioK1 derived peptide interacts with a novel PPI site.     

Microstructure of mayenite 12CaO·7Al2O3 and electron emission characteristics

Electron emission characteristic, electrical conductivity of polycrystalline mayenite (12CaO·7Al₂O₃) electride, formation of [Ca₂₄Al₂₈O₆₄]⁴⁺(e⁻)₄ framework as a function of phase content, and microstructure have been investigated. The mayenite microstructure was investigated using high-resolution transmission microscopy which revealed the type cage structure of 12CaO·7Al₂O₃ partially filled by extra-framework oxygen ions. Incorporation of electrons by means of carbon ion template 12CaO·7Al₂O₃ produces complex structure, and an incomplete ion template 12CaO·7Al₂O₃ structure consisting of mixture of a [Ca₂₄Al₂₈O₆₄]⁴⁺(e⁻)₄ and [Ca₂₄Al₂₈O₆₄]⁴⁺(O²⁻)₂ framework had a direct effect on the electron emission. Surface chemistry and stability of the 12CaO·7Al₂O₃ electride have been studied using x-ray photoelectron spectroscopy. The work function of phase pure 12CaO·7Al₂O₃ electride was determined from direct thermionic emission data and compared to the measurement from ultraviolet photoelectron spectroscopy (UPS). Depending on the extent of ion template of 12CaO·7Al₂O₃ structure, a work function of 0.9–1.2 eV and 2.1–2.4 eV has been measured and thermionic emission initiating at 600°C.     

Novel TTLL5 Variants Associated with Cone-Rod Dystrophy and Early-Onset Severe Retinal Dystrophy

Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects.     

Effects of Model Protein Environments on the Dynamics of Proton Wires

The multiconfigurational molecular dynamics with quantum transitions (MC-MDQT) method is utilized to study the impact of model protein environments on the dynamics of proton wires. The MC-MDQT method allows the realtime nonequilibrium quantum dynamical simulation of proton transport along water chains and provides a framework for analyzing the detailed dynamical mechanisms of these multiple proton transfer reactions. In this paper, the protein environment is modeled by applying structural restraints to the oxygen atoms of the chain, by applying external electric fields, and by including solvating water molecules hydrogen-bonded to the ends of the water chain. Our simulations illustrate that the protein environment could strongly impact the dynamics of proton wires through a combination of structural restraints, fluctuating electric fields, solvation, and hydrogen bonding. Our simulations also indicate that quantum effects such as hydrogen tunneling and nonadiabatic transitions play a significant role under certain nonequilibrium conditions.     

Modelling biological efficacy decrease and rate of degradation of chlorpyrifos-methyl on wheat stored under controlled conditions

Insecticide residue degradation and pest survival were observed in wheat treated with a low dose of chlorpyrifos-methyl. Treated wheat was stored in small batches at three controlled temperatures and two levels of moisture content of grain, in equilibrium with r.h. in order to stabilise the water activity in the grain during a storage period of 126 d after insecticide application. Every 3 weeks, samples were taken from treated and untreated control grain in each storage condition. Chlorpyrifos-methyl residues declined regularly with time of storage and an exponential negative regression was fitted with high correlation coefficients in most situations of storage temperature and grain water activity (Aw). A multivariate model to show the respective influence of controlled variables involved in the model of residues breakdown (time, Aw, and temperature) was built up through a multiple regression. This model showed the respective importance of the water activity of grain kernels, temperature and formulation of chlorpyrifos-methyl and their combinations on the decline of residues. Simultaneously, the effectiveness of the residues was checked through bioassays with two target species: Sitophilus oryzae and Tribolium castaneum. Taking into account the intentionally low initial applied dose of chlorpyrifos-methyl, the period after application achieving complete kill of the two test insects was rather short and did not exceed 105 d for S. oryzae in the best conditions for control, i.e. low moisture content and temperature. For high Aw (0.8) and storage temperature 30°C, T. castaneum was effectively controlled (more than 95% kill) only on the day after the treatment, survival occurring at the next test date 21 d after the application. High moisture content and temperature and their interactions were the main variables influencing the decrease in the biological effectiveness with time. The concentration threshold for insect survival was slightly below 1 ppm chlorpyrifos-methyl and was influenced by storage and grain conditions. Implications of these findings on storage pest management practices and on the ability to predict the period of biological effectiveness of residues of chlorpyrifos-methyl are discussed.     

Impact of three different TiO2 morphologies on hydrogen evolution by methanol assisted water splitting: Nanoparticles, nanotubes and aerogels

Increasing the activity of a photocatalyst goes through the improvement of both its absorption (light) and adsorption (reactant) properties. For a given semiconducting material, the charge carrier separation is also a very important step. Properly combining chosen phases is one option to improve this separation (example of the commercial P25) and depositing platinum on the surface of the catalyst, another one. In some cases, coupling both may nevertheless lead to a decrease of photoactivity or at least limit the potentiality of the catalyst. A third option, consisting in modifying the morphology of the photoactive phase, has shown very promising results.In this study, we have elaborated, characterized and evaluated the hydrogen evolution potentiality (through methanol assisted water splitting) of different TiO₂ morphologies: nanoparticles, nanotubes and aerogels. These materials have shown different behaviours depending on both their composition and morphology. Different types of separation processes have been claimed to account for the observed different photoactivities, with more or less pronounced synergetic effects, due to: the use of Pt as a co-catalyst, the mixture of different TiO₂ phases (anatase and TiO₂(B) or rutile) and the specific morphology of the samples (nanotubes or aerogels). Among all the tested samples, the TiO₂ aerogel supported Pt one exhibited very promising performances, three times as active as P25 supported Pt, which is already much more active than pure P25 in our testing conditions.     

Balancing nutrient inputs to Lake Kivu

The primary production in meromictic Lake Kivu is sustained by external nutrient inputs and by internal loading due to upwelling caused by sub-aquatic sources. We present here the results of external loading of phosphorus (P), nitrogen (N) and silica (Si) by rivers and atmospheric deposition measured from 2006 to 2008. These external inputs are compared to internal loading. The input of soluble-reactive P (SRP), supplied in equal parts from rivers and atmospheric deposition, adds up to 230 t P yr^− 1, 20 times less than total P load. Ammonium (mainly via rainwater) and nitrate (mainly via rivers) are primary sources of the dissolved N load (5400 t N yr^− 1), with both species contributing ∼ 50%. Dissolved Si input (40,000 t Si yr^− 1) is unique in that only ∼ 60% enters by rivers, while the remaining ∼ 40% comes from sub-aquatic sources and atmospheric deposition is negligible. Based on the molar nutrient ratios, we identify P as the limiting factor for algae production. Despite the strong anthropogenic impact on the catchment and the high particle erosion (74 t km^− 2 yr^− 1), the area-specific nutrient mobilization is rather low. The external nutrient input is therefore not the cause for the reported increase of methane production in the last decades. External loading to the epilimnion plays a lesser role for all three nutrients (∼ 10% for SRP, ∼ 25% for dissolved N and ∼ 45% for dissolved Si), as compared to the lake-internal loading by upwelling (90%, 75% and 55%, respectively). Lake Kivu, therefore, is similar to other East African large lakes in that the internal loading exceeds the external loading. Despite the substantial uncertainty of the load estimates of up to 50%, we can conclude that the observed nutrient input is consistent with the primary production of 260 g C m^− 2 yr^− 1 recently measured by Sarmento et al. (2006) and also consistent with the lake-internal fluxes established by Pasche et al. (in press).     

Wine phenolics—analysis of low molecular weight components by high performance liquid chromatography

Low molecular weight phenolic compounds were separated by high performance liquid chromatography on hydrocarbon-bonded reverse phase packings, with a water-methanol elution gradient. Phenolic compounds were extracted from wine with ethyl acetate. A first extraction at pH 7 enabled isolation of neutral molecules (catechins, procyanidins, flavonols, aromatic alcohols); a second extraction at pH 2 was performed to extract phenolic acids. Successive injections of these two extracts in the chromatograph gave the distribution of the different phenolic compounds in the wine under analysis. Analytical data are given for low molecular weight phenolic compounds present in young red Bordeaux wines from different vine cultivars.     

Marital status, pregnancy planning, and role overload: A mediated-moderation model of parenting satisfaction.

This longitudinal study investigated the presence of a moderating effect of pregnancy planning on the relationship between marital status and parenting satisfaction of couples experiencing the transition to parenthood and verified whether this moderating effect is mediated by role overload. Data were collected from 150 Canadian couples during the 3rd trimester of pregnancy and at 9 months postpartum. Findings reveal that when the pregnancy is planned, the poorer parenting satisfaction reported by cohabiting fathers in comparison with their married counterparts can be explained by cohabiting men’s higher levels of role overload. Women’s levels of parenting satisfaction are also influenced by their own and their partner’s experiences of role overload. Results are discussed in terms of the respective values and lifestyles of cohabiting and married couples and specifically in terms of their different attitudes toward egalitarianism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)