Enhanced levels of methionine and cysteine in transgenic alfalfa (Medicago sativa L.) plants over-expressing the Arabidopsis cystathionine gamma-synthase gene

With the aim of increasing the methionine level in alfalfa (Medicago sativa L.) and thus improving its nutritional quality, we produced transgenic alfalfa plants that expressed the Arabidopsis cystathionine gamma-synthase (AtCGS), the enzyme that controls the synthesis of the first intermediate metabolite in the methionine pathway. The AtCGS cDNA was driven by the Arabidopsis rubisco small subunit promoter to obtain expression in leaves. Thirty transgenic plants were examined for the transgene protein expression, and four lines with a high expression level were selected for further work. In these lines, the contents of methionine, S-methylmethionine (SMM), and methionine incorporated into the water-soluble protein fraction increased up to 32-fold, 19-fold, and 2.2-fold, respectively, compared with that in wild-type plants. Notably, in these four transgenic lines, the levels of free cysteine (the sulphur donor for methionine synthesis), glutathione (the cysteine storage and transport form), and protein-bound cysteine increased up to 2.6-fold, 5.5-fold, and 2.3-fold, respectively, relative to that in wild-type plants. As the transgenic alfalfa plants over-expressing AtCGS had significantly higher levels of both soluble and protein-bound methionine and cysteine, they may represent a model and target system for improving the nutritional quality of forage crops.     

Grassland Leafhoppers (Hemiptera: Auchenorrhyncha) as Indicators of Habitat Condition – A Comparison of between-site and between-year differences in Assemblage Composition

The Auchenorrhyncha (leafhoppers) show great potential as indicators of grassland habitat quality, which would make them useful as a conservation tool. However, they are known to have labile populations. The relative importance of site identity and the year of sampling in the composition of leafhopper assemblages on chalk grassland are assessed for two sets of sites sampled twice. The study included a total of 95 sites (one set of 54, the other of 41), and demonstrated that for both sets the vegetation community and geographical location had high explanatory value, while the influence of year was small. The conclusion is that, notwithstanding population fluctuations, the leafhopper assemblages are a good indicator of habitat quality, and represent a potentially valuable tool in grassland conservation and restoration.     

Quality control system of the endoplasmic reticulum and related diseases

The quality control (QC) system of the endoplasmic reticulum (ER) is an important monitoringmechanism in the protein maturation process,which ensures export of properly folded proteins from the ER.Incorrectly or incompletely folded proteins are retained in the ER for refolding or degradation by the ER-residing proteasome.The calnexin/calreticulin cycle and ER-associated degradation are the key elements inQC.These two mechanisms work together to allow incorrectly folded proteins have additional opportunitiesto achieve their native conformations.The QC dysfunction is involved in many diseases caused by mutantproteins,many of which are causes of neurodegenerative disorders.A better understanding of molecularregulation in the QC system will uncover the molecular pathogenic mechanisms of many diseases caused byprotein misfolding and help discover novel strategies for preventing or treating these diseases.     

Seminal plasma zinc concentration and α-glucosidase activity with respect to semen quality

This study was conducted to examine the relationship between the concentration of zinc and neutral α-glucosidase (NAG) with semen quality. Semen samples from 75 male partners of couples who were attending the Obstetrics and Gynecology Department were analyzed for semen quality. Based on sperm count, the subjects were divided into three groups. Zinc and neutral α-glucosidase activity were estimated in seminal plasma. Results showed that mean the α-glucosidase activity was lowest among the azoospermic group with respect to oligozoospermic and normozoospermic groups. Mean zinc levels were also lower among azoospermics compared to oligozoospermic and normospermic groups. The difference was statistically significant (p<0.05). A significant positive correlation was observed between zinc levels and sperm count (r=0.29, p<0.05) and zinc and α-glucosidase activity (r=0.31, p<0.05) in seminal plasma. These results suggest that zinc and neutral α-glucosidase seem to play an important role in human reproduction.     

Proteasome-Related HslU and HslV Genes Typical of Eubacteria Are Widespread in Eukaryotes

Many eubacteria contain an ATP-dependent protease complex, which is built by multiple copies of the HslV and HslU proteins and is therefore called HslVU. HslU proteins are AAA + ATPases, while HslV proteins are proteases that show highly significant similarity to β subunits of proteasomes. Therefore, the HslVU complex has been envisaged as a precursor or ancestral type of proteasome. Here we show that species of most of the main eukaryotic lineages have HslU and HslV genes very similar to those found in proteobacteria. We have detected them in amoebozoa, plantae, chromoalveolata, rhizaria, and excavata species. Phylogenetic analyses suggest that these genes have been obtained by endosymbiosis from the proteobacterial ancestor that gave rise to eukaryotic mitochondria. The products encoded by these eukaryotic genes adopt, according to modeling based on the known crystal structures of prokaryotic HslU and HslV proteins, conformations that are compatible with their being fully active, suggesting that functional HslVU complexes may be present in many eukaryotic species. [Reviewing Editor: Dr. Yves Van de Peer]     

Prevention of amyloid fibril formation of amyloidogenic chicken cystatin by site-specific glycosylation in yeast

To address the role of glycosylation on fibrillogenicity of amyloidogenic chicken cystatin, the consensus sequence for N-linked glycosylation (Asn106-Ile108 --> Asn106-Thr108) was introduced by site-directed mutagenesis into the wild-type and amyloidogenic chicken cystatins to construct the glycosylated form of chicken cystatins. Both the glycosylated and unglycosylated forms of wild-type and amyloidogenic mutant I66Q cystatin were expressed and secreted in a culture medium of yeast Pichia pastoris transformants. Comparison of the amount of insoluble aggregate, the secondary structure, and fibrillogenicity has shown that the N-linked glycosylation could prevent amyloid fibril formation of amyloidogenic chicken cystatin secreted in yeast cells without affecting its inhibitory activities. Further study showed this glycosylation could inhibit the formation of cystatin dimers. Therefore, our data strongly suggested that the mechanism causing the prevention of amyloidogenic cystation fibril formation may be realized through suppression of the formation of three-dimensional domain-swapped dimers and oligomers of amyloidogenic cystatin by the glycosylated chains at position 106.     

Body image and quality of life in post massive weight loss body contouring patients

Objective: Because post‐bariatric surgery patients undergo massive weight loss, the resulting skin excess can lead to both functional problems and profound dissatisfaction with appearance. Correcting skin excess could improve all these corollaries, including body image. Presently, few data are available documenting body image and weight‐related quality of life in this population. Research Methods and Procedures: Eighteen patients who underwent both bariatric surgery and body contouring completed our study. Both established surveys and new surveys designed specifically for the study were used to assess body perception and ideals, quality of life, and mood. Patients were surveyed at the following time‐points: pre‐body contouring (after massive weight loss) and both 3 and 6 month post‐body contouring. Statistical testing was performed using Student's t test and ANOVA. Results: The mean age of the patients was 46 ± 10 years (standard deviation). Quality of life improved after obesity surgery and was significantly enhanced after body contouring. Three months after body contouring, subjects ascribed thinner silhouettes to both current appearance and ideal body image. Body image also improved with body contouring surgery. Mood remained stable over 6 months. Discussion: Body contouring after surgical weight loss improved both quality‐of‐life measurements and body image. Initial body dissatisfaction did not correlate with mood. Body contouring improved body image but produced dissatisfaction with other parts of the body, suggesting that as patients become closer to their ideal, these ideals may shift. We further developed several new assessment methods that may prove useful in understanding these post‐surgical weight loss patients.     

Dietary quality predicts adult weight gain: findings from the Framingham Offspring Study

Objective: We tested the hypothesis that dietary quality, measured by adherence to the Dietary Guidelines, was related to weight change in adults. Research Methods and Procedures: Dietary intake was assessed among 2245 adult men and women (average age, 49 to 56 years) in the Framingham Offspring cohort. Three‐day dietary records were collected in 1984 to 1988 and again in 1991 to 1996. Weight change was measured over 8 years after each assessment. A five‐point diet quality index (DQI) was computed based on mean nutrient intake levels from each set of diet records. One DQI point was contributed for each of five nutrients if intake met Dietary Guidelines for total and saturated fat, cholesterol, sodium, and carbohydrate. Gender‐specific generalized estimating equations pooled data across the two assessments to relate DQI to 8‐year weight gain. Results: Men and women with higher DQI scores gained less weight during follow‐up (p < 0.05). Average gain over 8 years was ～3 pounds among those with highest scores, compared with 5 to 8 pounds among those with lower scores. Smoking cessation was an important predictor of weight gain, accounting for about a 5‐ to 9‐pound difference in weight gain. Discussion: A high‐quality diet, one that is consistent with the Dietary Guidelines, may help curb rising rates of obesity at the population level. Poor compliance with the Guidelines, rather than the guidelines themselves, is likely responsible for the weight gain observed in the American population. Adoption of an eating pattern consistent with the Dietary Guidelines should facilitate population weight control if sustained long term.     

Construct validity of the Short Form-36 Health Survey and its relationship with BMI in obese outpatients

Objective: To investigate the construct validity of the Short Form‐36 (SF‐36) Health Survey questionnaire in obese patients. Research Methods and Procedures: Our series consisted of 1735 obese patients (age, 44.7 ± 11.0 years; 1346 women) consecutively enrolled in the QUOVADIS study, an observational multicenter study of obese treatment‐seeking outpatients. The construct validity of the SF‐36 was assessed by main component analysis. Age‐, gender‐, and education‐adjusted general linear models were used to investigate the relationship between BMI and SF‐36 domains or factors identified by main component analysis. Results: BMI was significantly associated with poor health‐related quality of life in all eight SF‐36 domains, and the strongest association was observed with physical activity. Main components analysis generated a six‐factor solution explaining 59% of the observed variance. BMI was strongly associated with factors based on the loading of items regarding the physical activity domain and factors based on role‐physical and role‐emotional items or general health and bodily pain items. In contrast, mental health‐, vitality‐, and social functioning‐based factors were not related to BMI. Discussion: In obese treatment‐seeking outpatients, the clustering of SF‐36 items in main components is not significantly different from the domain‐based approach generally used, thus confirming the robustness of such a generic questionnaire in this specific condition. However, the peculiar clustering of some SF‐36 items and their relationship with BMI suggest that the health‐related quality of life profile of subjects belonging to that population may be better described with alternative aggregations of the SF‐36 items or with disease‐tailored questionnaires.     

Recognition of lumenal prion protein aggregates by post-ER quality control mechanisms is mediated by the preoctarepeat region of PrP

Prion diseases are fatal transmissible neurodegenerative disorders linked to an aberrant conformation of the cellular prion protein (PrP(c)). We have shown previously that the chemical compound suramin induced aggregation of fully matured PrP(c) in post-ER compartments, thereby, activating a post-ER quality control mechanism and preventing cell surface localization of PrP by intracellular re-routing of aggregated PrP from the Golgi/TGN directly to lysosomes. Of note, drug-induced PrP aggregates were not toxic and could easily be degraded by neuronal cells. Here, we focused on determining the PrP domains mediating these effects. Using PrP deletion mutants we show that intracellular re-routing but not aggregation depends on the N-terminal PrP (aa 23-90) and, more precisely, on the preoctarepeat domain (aa 23-50). Fusion of the PrP N-terminus to the GPI-anchored protein Thy-1 did not cause aggregation or re-routing of the chimeric protein, indicating that the N-terminus is only active in re-routing when prion protein aggregation occurs. Insertion of a region with a comparable primary structure contained in the PrP paralogue prnd/doppel (aa 27-50) into N-terminally deleted PrP re-established the re-routing phenotype. Our data reveal an important role for the conserved preoctarepeat region of PrP, namely controlling the intracellular trafficking of misfolded PrP.