Recessive mutations in the
gene cause Marinesco-Sjögren syndrome (MSS), a rare neuropediatric disorder. MSS-patients typically present with congenital cataracts, intellectual disability, cerebellar ...ataxia and progressive vacuolar myopathy. However, atypical clinical presentations associated with
mutations have been described over the last years; compound heterozygosity of SIL1 missense mutations even resulted in a phenotype not fulfilling the clinical diagnostic criteria of MSS. Thus, a read-out system to evaluate reliably the pathogenicity of amino acid changes in
is needed. Here, we aim to provide suitable cellular biomarkers enabling the robust evaluation of pathogenicity of SIL1 mutations.
Five
variants including one polymorphism (p.K132Q), three known pathogenic mutations (p.V231_I232del, p.G312R, and p.L457P) and one ambiguous missense variant (p.R92W) were studied along with the wild-type proteins in Hek293
models by cell biological assays, immunoprecipitation, immunoblotting, and immunofluorescence as well as electron microscopy. Moreover, the SIL1-interactomes were interrogated by tandem-affinity-purification and subsequent mass spectrometry.
Our combined studies confirmed the pathogenicity of p.V231_I232del, p.G312R, and p.L457P by showing instability of the proteins as well as tendency to form aggregates. This observation is in line with altered structure of the ER-Golgi system and vacuole formation upon expression of these pathogenic SIL1-mutants as well as the presence of oxidative or ER-stress. Reduced cellular fitness along with abnormal mitochondrial architecture could also be observed. Notably, both the polymorphic p.K132Q and the ambiguous p.R92W variants did not elicit such alterations. Study of the SIL1-interactome identified POC1A as a novel binding partner of wild-type SIL1; the interaction is disrupted upon the presence of pathogenic mutants but not influenced by the presence of benign variants. Disrupted SIL1-POC1A interaction is associated with centrosome disintegration.
We developed a combination of cellular outcome measures to evaluate the pathogenicity of
variants in suitable
models and demonstrated that the p. R92W missense variant is a polymorphism rather than a pathogenic mutation leading to MSS.
Yeast impact homolog 1 (Yih1), or IMPACT in mammals, is part of a conserved regulatory module controlling the activity of General Control Nonderepressible 2 (Gcn2), a protein kinase that regulates ...protein synthesis. Yih1/IMPACT is implicated not only in many essential cellular processes, such as neuronal development, immune system regulation and the cell cycle, but also in cancer. Gcn2 must bind to Gcn1 in order to impair the initiation of protein translation. Yih1 hinders this key Gcn1‐Gcn2 interaction by binding to Gcn1, thus preventing Gcn2‐mediated inhibition of protein synthesis. Here, we solved the structures of the two domains of Saccharomyces cerevisiae Yih1 separately using Nuclear Magnetic Resonance and determined the relative positions of the two domains using a range of biophysical methods. Our findings support a compact structural model of Yih1 in which the residues required for Gcn1 binding are buried in the interface. This model strongly implies that Yih1 undergoes a large conformational rearrangement from a latent closed state to a primed open state to bind Gcn1. Our study provides structural insight into the interactions of Yih1 with partner molecules.
This article systematically reviews the current literature around the sustainable attitude-behavior gap faced by shoppers who seek to shop sustainably at the supermarket. We analyze why household ...shoppers in general say they understand the science but do not follow through by placing sustainable products in the supermarket trolley. Using the domain-based systematic literature review method, the study reveals that the majority of scholarship to date has focused on the role of the individual consumer, but even the most sustainably motivated shopper can encounter difficulty shopping sustainably. Issues such as trust of the supermarket, availability, placement, accessibility, and price, which are outside the control of the household shopper, play a role in whether the shopper can successfully meet their sustainable objective. We propose an alternative scholarship lens by constructing a framework of sustainable grocery behaviour that recognizes sustainable grocery shopping is not the domain of one actor, the everyday household shopper, but it is a complex dynamic macro system of differing participants ranging from retailers, suppliers, manufacturers, government, and NGO's to the household shopper. Adopting a systems view will be important to examine the entire supply chain complete with feedback loops to understand the intervention points available and needed to create the most advantageous sustainable grocery shopping environment that satisfies the demands of the sustainably conscious consumer, the retailer, the manufacturer, and that of the planet.
•Every day, people around the world report trying to shop sustainably at the supermarket, yet most fail.•Our research of 64 articles revealed that many of those reasons for failure are ouside the control of the individual shopper.•Recommend future research to take a macro systems approach to fully understand the key levers to sustainable grocery shopping.
Underinvestment in agriculture – a major cause of rural poverty – may be due to difficulties in detecting ‘contingency’, defined as the influence one may exert on the outcome of a decision-making ...situation. Recently experienced contingency may create a mismatch between perceived and actual contingency in an investment decision-making situation, leading to sub-optimal investment behaviour. To test this, we use an experiment with poor farmers in Uganda used to low levels of contingency, as many factors (e.g., the weather, pests, price fluctuations) obscure the link between farm investment and outcomes. We find that in situations in which some contingency is present, investment levels respond positively to recently experienced contingency. In situations in which no contingency is present (‘non-contingency’), investment responds negatively to recently experienced non-contingency. The findings that perceived contingency influences investment behaviour, and perceived contingency can be readily changed, may inform new behavioural policies to promote agricultural investment.
•From psychology we use the concept of contingency – the extent to which one can influence outcomes – to shed light on investment behaviour of farmers.•Recently experienced contingency or non-contingency influences farmers’ perceived contingency in a new investment setting, which in turn influences their investment behaviour.•More contingency recently experienced increases farmers’ willingness to make risky investments where there is contingency.•Farmers who recently experienced non-contingency invest less costly time in a setting characterized by non-contingency.•A mismatch between perceived and actual contingency may lead to sub-optimal investment behaviour.
Evidence-based diagnostic methods have clinical and research applications in neuropsychology. A flexible Bayesian model was developed to yield diagnostic posttest probabilities from a single person's ...neuropsychological score profile by utilizing sample descriptive statistics of the test battery across diagnostic populations of interest.
Three studies examined the model's performance. One simulation examined estimation accuracy of true
-scores. A diagnostic accuracy simulation utilized descriptive statistics from two popular neuropsychological tests, the Wechsler Adult Intelligence Scale-IV (WAIS-IV) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The final simulation examined posterior predictive accuracy of scores to those reported in the WAIS manual.
The model produced minimally biased z-score estimates (root mean square errors: .02-.18) with appropriate credible intervals (95% credible interval empirical coverage rates: .94-1.00). The model correctly classified 80.87% of simulated normal, mild cognitive impairment, and Alzheimer's disease cases using a four subtest WAIS-IV and the RBANS compared to accuracies of 60.67-65.60% from alternative methods. The posterior predictions of raw scores closely aligned to percentile estimates published in the WAIS-IV manual.
This model permits estimation of posttest probabilities for various combinations of neuropsychological tests across any number of clinical populations with the principal limitation being the accessibility of applicable reference samples. The model produced minimally biased estimates of true
-scores, high diagnostic classification rates, and accurate predictions of multiple reported percentiles while using only simple descriptive statistics from reference samples. Future nonsimulation research on clinical data is needed to fully explore the utility of such diagnostic prediction models.
The major fungal pathogen of humans, Candida albicans, is exposed to reactive nitrogen and oxygen species following phagocytosis by host immune cells. In response to these toxins, this fungus ...activates potent anti-stress responses that include scavenging of reactive nitrosative and oxidative species via the glutathione system. Here we examine the differential roles of two glutathione recycling enzymes in redox homeostasis, stress adaptation and virulence in C. albicans: glutathione reductase (Glr1) and the S-nitrosoglutathione reductase (GSNOR), Fdh3. We show that the NADPH-dependent Glr1 recycles GSSG to GSH, is induced in response to oxidative stress and is required for resistance to macrophage killing. GLR1 deletion increases the sensitivity of C. albicans cells to H2O2, but not to formaldehyde or NO. In contrast, Fdh3 detoxifies GSNO to GSSG and NH3, and FDH3 inactivation delays NO adaptation and increases NO sensitivity. C. albicans fdh3⎔ cells are also sensitive to formaldehyde, suggesting that Fdh3 also contributes to formaldehyde detoxification. FDH3 is induced in response to nitrosative, oxidative and formaldehyde stress, and fdh3Δ cells are more sensitive to killing by macrophages. Both Glr1 and Fdh3 contribute to virulence in the Galleria mellonella and mouse models of systemic infection. We conclude that Glr1 and Fdh3 play differential roles during the adaptation of C. albicans cells to oxidative, nitrosative and formaldehyde stress, and hence during the colonisation of the host. Our findings emphasise the importance of the glutathione system and the maintenance of intracellular redox homeostasis in this major pathogen.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The cholesterol-lowering blockbuster drug pravastatin can be produced by stereoselective hydroxylation of the natural product compactin. We report here the metabolic reprogramming of the antibiotics ...producer Penicillium chrysogenum toward an industrial pravastatin production process. Following the successful introduction of the compactin pathway into the β-lactam–negative P. chrysogenum DS50662, a new cytochrome P450 (P450 or CYP) from Amycolatopsis orientalis (CYP105AS1) was isolated to catalyze the final compactin hydroxylation step. Structural and biochemical characterization of the WT CYP105AS1 reveals that this CYP is an efficient compactin hydroxylase, but that predominant compactin binding modes lead mainly to the ineffective epimer 6- epi -pravastatin. To avoid costly fractionation of the epimer, the enzyme was evolved to invert stereoselectivity, producing the pharmacologically active pravastatin form. Crystal structures of the optimized mutant P450 Pᵣₐᵥₐ bound to compactin demonstrate how the selected combination of mutations enhance compactin binding and enable positioning of the substrate for stereo-specific oxidation. Expression of P450 Pᵣₐᵥₐ fused to a redox partner in compactin-producing P. chrysogenum yielded more than 6 g/L pravastatin at a pilot production scale, providing an effective new route to industrial scale production of an important drug.
Significance Statins are successful widely used drugs that decrease the risk of coronary heart disease and strokes by lowering cholesterol levels. They selectively inhibit the key regulatory enzyme of the cholesterol synthesis pathway, thus lowering levels of plasma LDL (bad) cholesterol. Pravastatin is one of the leading and most effective statins, derived from the natural product compactin. However, pravastatin production involves a costly dual-step fermentation and biotransformation process. Here we present a single-step fermentative method for production of the active drug pravastatin. Reprogramming of the antibiotics-producing fungus Penicillium chrysogenum , with discovery and engineering of an enzyme involved in the hydroxylation of compactin, enables high level fermentation of the correct form of pravastatin to facilitate efficient industrial-scale statin drug production.
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•Lepidoptera formed a small proportion of capitulum-boring larvae on fireweed.•DNA barcoding revealed the native host ranges of two capitulum-boring moths.•Homoeosoma stenotea ...utilized six non-target Senecio species in the field.•Platyptilia sp. was uncommon and recorded on two non-target Senecio species.•Both moths appear unsuitable for countries with a diverse Senecio flora.
Senecio madagascariensis Poiret (Asteraceae; fireweed) is a target for biological control in Australia and Hawaii, due to its severe impacts on agriculture and grazed rangelands. Prioritized candidate biocontrol agents recorded in KwaZulu-Natal Province, South Africa (accepted as the plant’s region of origin) include capitulum-boring Lepidoptera. The seasonal abundance of capitulum-boring insects was studied on S. madagascariensis populations in KwaZulu-Natal during 2017/18. The host-plant affinities of lepidopteran associates were subsequently assessed by surveying 34 non-target native Senecio species in the same region. Cytochrome c oxidase subunit 1 mitochondrial gene barcoding was used to differentiate the endophagous larvae associated with the various host plants and link them with their adult stages. Monthly sampling revealed low numbers of capitulum-boring insects in relation to available capitula, with no significant variation amongst sites or months. Larvae largely comprised Coleoptera (72.8%), with fewer Lepidoptera (15.8%) and Diptera (11.4%). Adults reared from the capitula comprised Coleoptera (Nitidulidae), Diptera (Agromyzidae, Cecidomyiidae, Tephritidae) and Lepidoptera (Pterophoridae, Pyralidae). The host-range study revealed 14 lepidopteran taxa on 13 Senecio species, with Homoeosoma stenotea Hampson (Pyralidae) and an unidentified species of Platyptilia Hübner (Pterophoridae) comprising the most abundant species and recorded mostly on S. madagascariensis. However, H. stenotea was recorded on six, and Platyptilia sp. on two, non-target Senecio species. These results suggest unacceptably broad host ranges for countries like Australia that host a diverse Senecio flora and require highly specific biocontrol agents. Both species may warrant further investigation in Hawaii, where there are no native Senecio species.
Salmonids are one of the most intensely studied fish, in part due to their economic and environmental importance, and in part due to a recent whole genome duplication in the common ancestor of ...salmonids. This duplication greatly impacts species diversification, functional specialization, and adaptation. Extensive new genomic resources have recently become available for Atlantic salmon (Salmo salar), but documentation of allelic versus duplicate reference genes remains a major uncertainty in the complete characterization of its genome and its evolution.
From existing expressed sequence tag (EST) resources and three new full-length cDNA libraries, 9,057 reference quality full-length gene insert clones were identified for Atlantic salmon. A further 1,365 reference full-length clones were annotated from 29,221 northern pike (Esox lucius) ESTs. Pairwise dN/dS comparisons within each of 408 sets of duplicated salmon genes using northern pike as a diploid out-group show asymmetric relaxation of selection on salmon duplicates.
9,057 full-length reference genes were characterized in S. salar and can be used to identify alleles and gene family members. Comparisons of duplicated genes show that while purifying selection is the predominant force acting on both duplicates, consistent with retention of functionality in both copies, some relaxation of pressure on gene duplicates can be identified. In addition, there is evidence that evolution has acted asymmetrically on paralogs, allowing one of the pair to diverge at a faster rate.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Lateral epicondylitis is a common musculoskeletal disorder of the upper limb. Corticosteroid injection has been widely used as a major mode of treatment. However, better understanding of the ...pathophysiology of the disease led to a major change in treating the disease, with new options including platelet-rich plasma (PRP) are currently used. Objectives/research aim: To systematically evaluate the effect of corticosteroid versus PRP injections for the treatment of LE.
PRP injections provide longer-term therapeutic effect and less rate of complications compared to corticosteroid injection.
Level 2 evidence (4 included studies are of level 1 evidence, 1 study of level 2 evidence).
Systematic Review (according to PRISMA guidelines).
Eleven databases used to search for relevant primary studies comparing the effects of corticosteroid and PRP injections for the treatment of LE. Quality appraisal of studies performed using Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0, CASP Randomised Controlled Trial Checklist, and SIGN Methodology Checklist 2.
732 papers were identified. Five randomised controlled trials (250 Patients) met the inclusion criteria.
Corticosteroid injections provided rapid symptomatic improvement with maximum effect at 6/8/8 weeks before symptoms recurrence, whereas PRP showed slower ongoing improvements up to 24/52/104 weeks(3 studies). Corticosteroid showed more rapid symptomatic improvement of symptoms compared to PRP up to the study end-point of 3 months(1 study). Comparable therapeutic effects of corticosteroid and PRP were observed at 6 weeks(1 study). Ultrasonographic Findings: (1) Doppler activity decreased more significantly in patients who received corticosteroid compared to PRP. (2) Reduced tendon thickness and more patients with cortical erosion noted in corticosteroid group whereas increased tendon thickness and less number of patients with common extensor tendon tears noted in PRP group. (3) Fewer patients reported Probe-induced tenderness and oedema in the common extensor tendon in both corticosteroid and PRP groups (2 studies).
Corticosteroid injections provide rapid therapeutic effect in the short-term with recurrence of symptoms afterwards, compared to the relatively slower but longer-term effect of platelet-rich plasma.
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