Small heat shock proteins (sHSPs) are an ubiquitous protein family found in archaea, bacteria and eukaryotes. In plants, as in other organisms, sHSPs are upregulated by stress and are proposed to act ...as molecular chaperones to protect other proteins from stress-induced damage. sHSPs share an ‘α-crystallin domain’ with a β-sandwich structure and a diverse N-terminal domain. Although sHSPs are 12–25 kDa polypeptides, most assemble into oligomers with ≥ 12 subunits. Plant sHSPs are particularly diverse and numerous; some species have as many as 40 sHSPs. In angiosperms this diversity comprises ≥ 11 sHSP classes encoding proteins targeted to the cytosol, nucleus, endoplasmic reticulum, chloroplasts, mitochondria and peroxisomes. The sHSPs underwent a lineage-specific gene expansion, diversifying early in land plant evolution, potentially in response to stress in the terrestrial environment, and expanded again in seed plants and again in angiosperms. Understanding the structure and evolution of plant sHSPs has progressed, and a model for their chaperone activity has been proposed. However, how the chaperone model applies to diverse sHSPs and what processes sHSPs protect are far from understood. As more plant genomes and transcriptomes become available, it will be possible to explore theories of the evolutionary pressures driving sHSP diversification.
Small heat shock proteins are a diverse, ancient, and important family of proteins. All organisms possess small heat shock proteins (sHSPs), indicating that these proteins evolved very early in the ...history of life prior to the divergence of the three domains of life (Archaea, Bacteria, and Eukarya). Comparing the structures of sHSPs from diverse organisms across these three domains reveals that despite considerable amino acid divergence, many structural features are conserved. Comparisons of the sHSPs from diverse organisms reveal conserved structural features including an oligomeric form with a β-sandwich that forms a hollow ball. This conservation occurs despite significant divergence in primary sequences. It is well established that sHSPs are molecular chaperones that prevent misfolding and irreversible aggregation of their client proteins. Most notably, the sHSPs are extremely diverse and variable in plants. Some plants have >30 individual sHSPs. Land plants, unlike other groups, possess distinct sHSP subfamilies. Most are highly up-regulated in response to heat and other stressors. Others are selectively expressed in seeds and pollen, and a few are constitutively expressed. As a family, sHSPs have a clear role in thermotolerance, but attributing specific effects to individual proteins has proved challenging. Considerable progress has been made during the last 15 years in understanding the sHSPs. However, answers to many important questions remain elusive, suggesting that the next 15 years will be at least equally rewarding.
ATPase family AAA domain-containing 3 (ATAD3) proteins are unique mitochondrial proteins that arose deep in the eukaryotic lineage but that are surprisingly absent in Fungi and Amoebozoa. These ...∼600-amino acid proteins are anchored in the inner mitochondrial membrane and are essential in metazoans and Arabidopsis thaliana. ATAD3s comprise a C-terminal ATPases Associated with a variety of cellular Activities (AAA+) matrix domain and an ATAD3_N domain, which is located primarily in the inner membrane space but potentially extends to the cytosol to interact with the ER. Sequence and structural alignments indicate that ATAD3 proteins are most similar to classic chaperone unfoldases in the AAA+ family, suggesting that they operate in mitochondrial protein quality control. A. thaliana has four ATAD3 genes in two distinct clades that appear first in the seed plants, and both clades are essential for viability. The four genes are generally coordinately expressed, and transcripts are highest in growing apices and imbibed seeds. Plants with disrupted ATAD3 have reduced growth, aberrant mitochondrial morphology, diffuse nucleoids and reduced oxidative phosphorylation complex I. These and other pleiotropic phenotypes are also observed in ATAD3 mutants in metazoans. Here, we discuss the distribution of ATAD3 proteins as they have evolved in the plant kingdom, their unique structure, what we know about their function in plants and the challenges in determining their essential roles in mitochondria.
Estrogen facilitates higher cognitive functions by exerting effects on brain regions such as the prefrontal cortex and hippocampus. Estrogen induces spinogenesis and synaptogenesis in these two brain ...regions and also initiates a complex set of signal transduction pathways via estrogen receptors (ERs). Along with the classical genomic effects mediated by activation of ER α and ER β, there are membrane-bound ER α, ER β, and G protein-coupled estrogen receptor 1 (GPER1) that can mediate rapid nongenomic effects. All key ERs present throughout the body are also present in synapses of the hippocampus and prefrontal cortex. This review summarizes estrogen actions in the brain from the standpoint of their effects on synapse structure and function, noting also the synergistic role of progesterone. We first begin with a review of ER subtypes in the brain and how their abundance and distributions are altered with aging and estrogen loss (e.g., ovariectomy or menopause) in the rodent, monkey, and human brain. As there is much evidence that estrogen loss induced by menopause can exacerbate the effects of aging on cognitive functions, we then review the clinical trials of hormone replacement therapies and their effectiveness on cognitive symptoms experienced by women. Finally, we summarize studies carried out in nonhuman primate models of age- and menopause-related cognitive decline that are highly relevant for developing effective interventions for menopausal women. Together, we highlight a new understanding of how estrogen affects higher cognitive functions and synaptic health that go well beyond its effects on reproduction.
Grape thaumatin-like proteins (TLPs) play roles in plant-pathogen interactions and can cause protein haze in white wine unless removed prior to bottling. Different isoforms of TLPs have different ...hazing potential and aggregation behavior. Here we present the elucidation of the molecular structures of three grape TLPs that display different hazing potential. The three TLPs have very similar structures despite belonging to two different classes (F2/4JRU is a thaumatin-like protein while I/4L5H and H2/4MBT are VVTL1), and having different unfolding temperatures (56 vs. 62°C), with protein F2/4JRU being heat unstable and forming haze, while I/4L5H does not. These differences in properties are attributable to the conformation of a single loop and the amino acid composition of its flanking regions.
Oenology, behind the more visible social and convivial aspects associated with the consumption of wine and spirits, has great complexity due to the coexistence of countless different styles of ...artisanal products, linked to the diversity of places grapes are grown and wine is produced, and its global distribution. Premium wine is not a commodity. To scientifically support such complexity requires an extremely rigorous and diversified scientific expertise, capable of supporting the continuous improvement of processes and products that are developed, evaluated, and offered on international markets. Rigorous chemical and sensory analyses are essential to this continuous process of improvement, and for several decades now have regularly brought together a large community of researchers from multidisciplinary backgrounds to share, discuss, and harmonize their knowledge and experience of wines. The 12th edition of In Vino Analytica Scientia 2022 was held in Neustadt, Germany, in July 2022. The conference was attended by over 240 delegates, from 23 nationalities, who shared different aspects of wine and spirits research, with 9 key note lectures; 37 full talks; 36 short communications, and over 200 posters. This special issue is a collection of full papers from a selection of contributed oral presentations and posters presented at the conference.
As sessile organisms, plants must be able to complete their life cycle in place and therefore tolerance to abiotic stress has had a major role in shaping biogeographical patterns. However, much of ...what we know about plant tolerance to abiotic stresses is based on studies of just a few plant species, most notably the model species Arabidopsis thaliana. In this study we examine natural variation in the stress responses of five diverse Boechera (Brassicaceae) species. Boechera plants were exposed to basal and acquired combined heat and high light stress. Plant response to these stresses was evaluated based on chlorophyll fluorescence measurements, induction of leaf chlorosis, and gene expression. Many of the Boechera species were more tolerant to heat and high light stress than A. thaliana. Gene expression data indicates that two important marker genes for stress responses: APX2 (Ascorbate peroxidase 2) and HsfA2 (Heat shock transcription factor A2) have distinct species-specific expression patterns. The findings of species-specific responses and tolerance to stress indicate that stress pathways are evolutionarily labile even among closely related species.
Healthy children achieve better educational outcomes which, in turn, are associated with improved health later in life. The World Health Organization's Health Promoting Schools (HPS) framework is a ...holistic approach to promoting health and educational attainment in school. The effectiveness of this approach has not yet been rigorously reviewed.
We searched 20 health, education and social science databases, and trials registries and relevant websites in 2011 and 2013. We included cluster randomised controlled trials. Participants were children and young people aged four to 18 years attending schools/colleges. HPS interventions had to include the following three elements: input into the curriculum; changes to the school's ethos or environment; and engagement with families and/or local communities. Two reviewers identified relevant trials, extracted data and assessed risk of bias. We grouped studies according to the health topic(s) targeted. Where data permitted, we performed random-effects meta-analyses.
We identified 67 eligible trials tackling a range of health issues. Few studies included any academic/attendance outcomes. We found positive average intervention effects for: body mass index (BMI), physical activity, physical fitness, fruit and vegetable intake, tobacco use, and being bullied. Intervention effects were generally small. On average across studies, we found little evidence of effectiveness for zBMI (BMI, standardized for age and gender), and no evidence for fat intake, alcohol use, drug use, mental health, violence and bullying others. It was not possible to meta-analyse data on other health outcomes due to lack of data. Methodological limitations were identified including reliance on self-reported data, lack of long-term follow-up, and high attrition rates.
This Cochrane review has found the WHO HPS framework is effective at improving some aspects of student health. The effects are small but potentially important at a population level.
Abstract Background The promotion of health equity, the absence of avoidable and unfair differences in health outcomes, is a global imperative. Systematic reviews are an important source of evidence ...for health decision makers but have been found to lack assessments of the intervention effects on health equity. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) is a 27-item checklist intended to improve transparency and reporting of systematic reviews. We developed an equity extension for PRISMA (PRISMA-E 2012) to help systematic reviewers identify, extract, and synthesize evidence on equity in systematic reviews. Methods and Findings In this explanation and elaboration article, we provide the rationale for each extension item. These items are additions or modifications to the existing PRISMA statement items, to incorporate a focus on equity. An example of good reporting is provided for each item as well as the original PRISMA item. Conclusions This explanation and elaboration document is intended to accompany the PRISMA-E 2012 statement and the PRISMA statement to improve understanding of the reporting guideline for users. The PRISMA-E 2012 reporting guideline is intended to improve transparency and completeness of reporting of equity-focused systematic reviews. Improved reporting can lead to better judgment of applicability by policy makers which may result in more appropriate policies and programs and may contribute to reductions in health inequities.
Organisms in a changing world Clark, Melody S.; Shabtay, Ariel; Waters, Elizabeth R. ...
Cell stress & chaperones,
09/2023, Letnik:
28, Številka:
5
Journal Article
PDF
