Ancient eukaryotic protein interactions illuminate modern genetic traits and disorders.

All eukaryotes share a common ancestor from roughly 1.5 - 1.8 billion years ago, a single-celled, swimming microbe known as LECA, the Last Eukaryotic Common Ancestor. Nearly half of the genes in modern eukaryotes were present in LECA, and many current genetic diseases and traits stem from these ancient molecular systems. To better understand these systems, we compared genes across modern organisms and identified a core set of 10,092 shared protein-coding gene families likely present in LECA, a quarter of which are uncharacterized. We then integrated >26,000 mass spectrometry proteomics analyses from 31 species to infer how these proteins interact in higher-order complexes. The resulting interactome describes the biochemical organization of LECA, revealing both known and new assemblies. We analyzed these ancient protein interactions to find new human gene-disease relationships for bone density and congenital birth defects, demonstrating the value of ancestral protein interactions for guiding functional genetics today.

Biopsychosocial determinants of physical activity and healthy eating for people with disability living in supported accommodation: A systematic review of qualitative research.

BACKGROUND: People with disability living in supported accommodation experience ongoing health disparities. Physical activity and dietary quality are factors that may minimise the risk of chronic disease, however this population may experience a range of biopsychosocial barriers to physical activity and healthy eating. OBJECTIVE: The aim of this review was to synthesise the biopsychosocial determinants of physical activity and healthy eating for people with disability living in supported accommodation, as reported by existing qualitative research. METHODS: A systematic review of qualitative evidence was conducted according to the JBI's methodological guidance. In September 2023, five academic databases were searched for relevant literature published since database inception. A secondary analysis of the results of included studies was guided by the International Framework for Functioning, Disability, and Health (ICF), using the ICF Linking Rules. RESULTS: A total of 31 articles were included. The analysis identified 154 determinants of physical activity and 112 determinants of healthy eating. Determinants were most prominently representative of environmental factors that captured the health promoting role and attitudes of staff, alongside the influence of the organisational context. CONCLUSION: This review provided evidence for the complex interactions between body functions and structures, activities and participation, personal factors, and the environment that influence physical activity and healthy eating within supported accommodation. Although there is a limited body of evidence to guide practice, the findings highlight the multifactorial nature of interventions that can be utilised by direct care professionals and adapted to the individual needs and interests of people with disability.

ARVCF catenin controls force production during vertebrate convergent extension.

The design of an animal's body plan is encoded in the genome, and the execution of this program is a mechanical progression involving coordinated movement of proteins, cells, and whole tissues. Thus, a challenge to understanding morphogenesis is connecting events that occur across various length scales. Here, we describe how a poorly characterized adhesion effector, Arvcf catenin, controls Xenopus head-to-tail axis extension. We find that Arvcf is required for axis extension within the intact organism but not within isolated tissues. We show that the organism-scale phenotype results from a defect in tissue-scale force production. Finally, we determine that the force defect results from the dampening of the pulsatile recruitment of cell adhesion and cytoskeletal proteins to membranes. These results provide a comprehensive understanding of Arvcf function during axis extension and produce an insight into how a cellular-scale defect in adhesion results in an organism-scale failure of development.

Twinfilin1 controls lamellipodial protrusive activity and actin turnover during vertebrate gastrulation.

The dynamic control of the actin cytoskeleton is a key aspect of essentially all animal cell movements. Experiments in single migrating cells and in vitro systems have provided an exceptionally deep understanding of actin dynamics. However, we still know relatively little of how these systems are tuned in cell-type-specific ways, for example in the context of collective cell movements that sculpt the early embryo. Here, we provide an analysis of the actin-severing and depolymerization machinery during vertebrate gastrulation, with a focus on Twinfilin1 (Twf1) in Xenopus. We find that Twf1 is essential for convergent extension, and loss of Twf1 results in a disruption of lamellipodial dynamics and polarity. Moreover, Twf1 loss results in a failure to assemble polarized cytoplasmic actin cables, which are essential for convergent extension. These data provide an in vivo complement to our more-extensive understanding of Twf1 action in vitro and provide new links between the core machinery of actin regulation and the specialized cell behaviors of embryonic morphogenesis.

Functional partitioning of a liquid-like organelle during assembly of axonemal dyneins.

Ciliary motility is driven by axonemal dyneins that are assembled in the cytoplasm before deployment to cilia. Motile ciliopathy can result from defects in the dyneins themselves or from defects in factors required for their cytoplasmic pre-assembly. Recent work demonstrates that axonemal dyneins, their specific assembly factors, and broadly-acting chaperones are concentrated in liquid-like organelles in the cytoplasm called DynAPs (Dynein Axonemal Particles). Here, we use in vivo imaging in Xenopus to show that inner dynein arm (IDA) and outer dynein arm (ODA) subunits are partitioned into non-overlapping sub-regions within DynAPs. Using affinity- purification mass-spectrometry of in vivo interaction partners, we also identify novel partners for inner and outer dynein arms. Among these, we identify C16orf71/Daap1 as a novel axonemal dynein regulator. Daap1 interacts with ODA subunits, localizes specifically to the cytoplasm, is enriched in DynAPs, and is required for the deployment of ODAs to axonemes. Our work reveals a new complexity in the structure and function of a cell-type specific liquid-like organelle that is directly relevant to human genetic disease.

A systematic, label-free method for identifying RNA-associated proteins in vivo provides insights into vertebrate ciliary beating machinery.

Cell-type specific RNA-associated proteins are essential for development and homeostasis in animals. Despite a massive recent effort to systematically identify RNA-associated proteins, we currently have few comprehensive rosters of cell-type specific RNA-associated proteins in vertebrate tissues. Here, we demonstrate the feasibility of determining the RNA-associated proteome of a defined vertebrate embryonic tissue using DIF-FRAC, a systematic and universal (i.e., label-free) method. Application of DIF-FRAC to cultured tissue explants of Xenopus mucociliary epithelium identified dozens of known RNA-associated proteins as expected, but also several novel RNA-associated proteins, including proteins related to assembly of the mitotic spindle and regulation of ciliary beating. In particular, we show that the inner dynein arm tether Cfap44 is an RNA-associated protein that localizes not only to axonemes, but also to liquid-like organelles in the cytoplasm called DynAPs. This result led us to discover that DynAPs are generally enriched for RNA. Together, these data provide a useful resource for a deeper understanding of mucociliary epithelia and demonstrate that DIF-FRAC will be broadly applicable for systematic identification of RNA-associated proteins from embryonic tissues.

A Pan-plant Protein Complex Map Reveals Deep Conservation and Novel Assemblies.

Plants are foundational for global ecological and economic systems, but most plant proteins remain uncharacterized. Protein interaction networks often suggest protein functions and open new avenues to characterize genes and proteins. We therefore systematically determined protein complexes from 13 plant species of scientific and agricultural importance, greatly expanding the known repertoire of stable protein complexes in plants. By using co-fractionation mass spectrometry, we recovered known complexes, confirmed complexes predicted to occur in plants, and identified previously unknown interactions conserved over 1.1 billion years of green plant evolution. Several novel complexes are involved in vernalization and pathogen defense, traits critical for agriculture. We also observed plant analogs of animal complexes with distinct molecular assemblies, including a megadalton-scale tRNA multi-synthetase complex. The resulting map offers a cross-species view of conserved, stable protein assemblies shared across plant cells and provides a mechanistic, biochemical framework for interpreting plant genetics and mutant phenotypes.

Systematic review of organisation-wide, trauma-informed care models in out-of-home care (OoHC) settings.

Trauma in early childhood has been shown to adversely affect children's social, emotional, and physical development. Children living in out-of-home care (OoHC) have better outcomes when care providers are present for children, physically, psychologically, and emotionally. Unfortunately, the high turnover of out-of-home carers, due to vicarious trauma (frequently resulting in burnout and exhaustion) can result in a child's trauma being re-enacted during their placement in OoHC. Organisation-wide therapeutic care models (encompassing the whole organisation, from the CEO to all workers including administration staff) that are trauma-informed have been developed to respond to the complex issues of abuse and neglect experienced by children who have been placed in OoHC. These models incorporate a range of therapeutic techniques, and provide an overarching approach and common language that is employed across all levels of the organisation. The aim of this study was to investigate the current empirical evidence for organisation-wide, trauma-informed therapeutic care models in OoHC. A systematic review searching leading databases was conducted for evidence of organisation-wide, trauma-informed, out-of-home care studies, between 2002 and 2017. Seven articles were identified covering three organisational models. Three of the articles assessed the Attachment Regulation and Competency framework (ARC), one study assessed the Children and Residential Experiences programme (CARE), and three studies assessed The Sanctuary Model. Risk of bias was high in six of the seven studies. Only limited information was provided on the effectiveness of the models identified through this systematic review, although the evidence did suggest that trauma-informed care models may have significantly positive outcomes for children in OoHC. Future research should focus on evaluating components of trauma-informed care models and assessing the efficacy of the various organisational care models currently available.

Understanding problematic eating in out-of-home care: The role of attachment and emotion regulation.

Children living in Out-of-Home Care (OoHC) are thought to be especially vulnerable to developing problematic eating behaviours due to their likelihood of having insecure attachment styles and emotion regulation deficits. Despite this increased risk, our understanding of problematic eating among children in OoHC is limited. Therefore, this study aimed to; (1) Explore the rate of problematic eating behaviours among children living in OoHC, specifically residential and foster care; (2) Investigate how carers manage problematic eating and (3) Understand carers' perceptions of the role of attachment and emotion regulation in relation to problematic eating in OoHC. Semi-structured interviews, focus groups, and surveys were conducted with residential care staff (n = 36) and foster carers (n = 8) in Victoria, Australia. Interviews were recorded, transcribed, and analysed for themes, and frequency data from the survey were generated. Residential and foster carers reported that approximately 38% of the children in their care displayed problematic eating behaviours at a clinical level. Both residential and foster carers commonly understood these behaviours as a function of the child's experiences of food deprivation and limited access to healthy foods prior to entering care which, they believe, has contributed to problems with regulating food intake and/or willingness to try new foods. Carers also commonly reported that the children in their care struggle to form attachments or regulate their emotions, which impacts carers ability to manage problematic eating. It is recommended that future interventions prioritise educating community service organisations (CSOs), responsible for delivering OoHC, to better recognise and address problematic eating behaviours. This will enable CSOs to train their residential and foster carers about how best to respond to and manage problematic eating behaviours.

"It's not as easy as saying, 'just get them to eat more veggies'": Exploring healthy eating in residential care in Australia.

Young people living in residential out-of-home care (henceforth OoHC) are at increased risk of becoming overweight or obese. Currently, recognition of the everyday mechanisms that might be contributing to excess weight for children and young people in this setting is limited. The aim of this study was to better understand the barriers and complexities involved in the provision of a 'healthy' food environment in residential OoHC. Heightening awareness of these factors and how they might compromise a young person's physical health, will inform the development, refinement and evaluation of more sensitive and tailored weight-related interventions for this population. The paper presents a nuanced picture of the complexity of everyday food routines in residential care, and illustrates the ways in which food is 'done' in care; how food can be both symbolic of care but also used to exercise control; the way in which food can be used to create a 'family-like' environment; and the impact of traumatic experiences in childhood on subsequent behaviours and overall functioning in relation to food. It is argued that a health agenda designed for a mainstream population ignores the very complex relationship that children in residential OoHC may have with food. It is recommended that future intervention approaches account for personal food biographies, trauma and children's social backgrounds and how these are implicated in everyday practices and interactions around food.

Do maternal perceptions of child eating and feeding help to explain the disconnect between reported and observed feeding practices?: A follow-up study.

Research demonstrates a mismatch between reported and observed maternal feeding practices. This mismatch may be explained by maternal cognitions, attitudes, and motivations relating to dyadic parent-child feeding interactions. These complex constructs may not be apparent during observations nor evidenced in self-report questionnaire. Therefore, the aim of this study was to use a qualitative approach to gain a more nuanced and contextualized understanding of (a) maternal perceptions of children's food intake control; (b) how parent-child mealtime interactions influence maternal feeding practices; and (c) ways in which mothers may promote healthy child eating and weight outcomes. Semistructured telephone interviews were conducted with 23 mothers (M = 38.4 ± 3.7 years of age) of preschool-aged children (M = 3.8 ± 0.6 years of age, 19 were normal weight, 14 were girls), who had previously completed child feeding questionnaire and participated in two home-based mealtime observations, 12 months apart. Interviews were recorded, transcribed, and themes extracted to create the database. Four major themes emerged: (a) Maternal confidence in children's ability to regulate food intake is variable; (b) Implementing strategies for nurturing healthy relationships with food beyond the dining table; (c) Fostering positive mealtime interactions is valued above the content of what children eat; and (d) Situation-specific practices and inconsistencies. Findings indicate that maternal feeding practices are shaped by both parent and child influences, and child feeding is mostly guided by controlling the family food environment, rather than by directly pressuring or restricting their child's eating. Results also highlighted the need for research to consider both parent and child influences on child feeding.

Descriptive study of carers' support, encouragement and modelling of healthy lifestyle behaviours in residential out-of-home care.

OBJECTIVE: Given the high prevalence of overweight/obesity among young people in residential out-of-home care (OOHC), and as their carers are in loco parentis, this research aimed: 1) to examine the healthy lifestyle cognitions and behaviours of residential carers; and 2) to describe resources needed to improve diet and/or physical activity outcomes for residents. METHODS: Cross-sectional data were collected from 243 residential carers. Measures included: demographics; knowledge of dietary/physical activity recommendations; self-reported encouragement/importance of health behaviours; physical activity/screen time (at work); unit 'healthiness'; and necessary resources for creating a healthy environment. RESULTS: Staff placed importance on the residents eating well and being physically active. However, examination of carer knowledge found significant gaps in staff education. Three key priority areas were identified to help build a healthy food and activity environment in residential OOHC: funding, professional development and policy. CONCLUSION: Carer knowledge of healthy lifestyles can be improved and they need to be well resourced to ensure children in public care settings live in a healthy environment. IMPLICATIONS: These findings may inform the development of ongoing professional development to improve carers' health literacy, as well as policy to support dietary/activity guidelines for the OOHC sector.

Fluorescent probes for tracking the transfer of iron-sulfur cluster and other metal cofactors in biosynthetic reaction pathways.

Iron-sulfur (Fe-S) clusters are protein cofactors that are constructed and delivered to target proteins by elaborate biosynthetic machinery. Mechanistic insights into these processes have been limited by the lack of sensitive probes for tracking Fe-S cluster synthesis and transfer reactions. Here we present fusion protein- and intein-based fluorescent labeling strategies that can probe Fe-S cluster binding. The fluorescence is sensitive to different cluster types ([2Fe-2S] and [4Fe-4S] clusters), ligand environments ([2Fe-2S] clusters on Rieske, ferredoxin (Fdx), and glutaredoxin), and cluster oxidation states. The power of this approach is highlighted with an extreme example in which the kinetics of Fe-S cluster transfer reactions are monitored between two Fdx molecules that have identical Fe-S spectroscopic properties. This exchange reaction between labeled and unlabeled Fdx is catalyzed by dithiothreitol (DTT), a result that was confirmed by mass spectrometry. DTT likely functions in a ligand substitution reaction that generates a [2Fe-2S]-DTT species, which can transfer the cluster to either labeled or unlabeled Fdx. The ability to monitor this challenging cluster exchange reaction indicates that real-time Fe-S cluster incorporation can be tracked for a specific labeled protein in multicomponent assays that include several unlabeled Fe-S binding proteins or other chromophores. Such advanced kinetic experiments are required to untangle the intricate networks of transfer pathways and the factors affecting flux through branch points. High sensitivity and suitability with high-throughput methodology are additional benefits of this approach. We anticipate that this cluster detection methodology will transform the study of Fe-S cluster pathways and potentially other metal cofactor biosynthetic pathways.

The impact of prairie strips on aphidophagous predator abundance and soybean aphid predation in agricultural catchments.

Reconstructing prairie vegetation in row crop-dominated agricultural landscapes may contribute to several ecosystem services, including the biological control of insect pests, such as the soybean aphid Aphis glycines Matsumura. The influence of the amount and configuration of reconstructed prairie vegetation on the delivery of ecosystem services was investigated in several small catchments at Neal Smith National Wildlife Refuge in Iowa. Treatments include catchments entirely in row crops under a no-till, corn-soybean (Zea mays L.-Glycine max [L.] Merrill) rotation, catchments with 10% of the land in prairie located at the base, and catchments with 10 or 20% of the land in multiple contour strips of prairie. During 2009 and 2011 growing seasons, we measured abundance and diversity of aphidophagous insect predators in response to treatment and habitat type (i.e., soybean, prairie). In 2011, we further studied the biological control of soybean aphids by artificially infesting uncaged and caged plants to prevent exposure from predators. While aphidophagous predators were more abundant in prairie, populations of key aphid predators did not significantly differ among treatments. Biological control of the soybean aphid did not differ among treatments or with distance from prairie. Our results suggest that prairie strips, in addition to providing soil and water quality benefits, may increase the populations of beneficial insects, but may not directly impact biocontrol. We propose several hypotheses to explain why we did not observe more soybean aphid predation with the increased abundance of aphidophagous predators in catchments containing prairie.

Promoting obesity prevention together with environmental sustainability.

There is mounting evidence that current food production, transport, land use and urban design negatively impact both climate change and obesity outcomes. Recommendations to prevent climate change provide an opportunity to improve environmental outcomes and alter our food and physical activity environments in favour of a 'healthier' energy balance. Hence, setting goals to achieve a more sustainable society offers a unique opportunity to reduce levels of obesity. In the case of children, this approach is supported with evidence that even from a young age they show emerging understandings of complex environmental issues and are capable of both internalizing positive environmental values and influencing their own environmental outcomes. Given young children's high levels of environmental awareness, it is easy to see how environmental sustainability messages may help educate and motivate children to make 'healthier' choices. The purpose of this paper is to highlight a new approach to tackling childhood obesity by tapping into existing social movements, such as environmental sustainability, in order to increase children's motivation for healthy eating and physical activity behaviours and thus foster more wholesome communities. We contend that a social marketing framework may be a particularly useful tool to foster behaviour change beneficial to both personal and environmental health by increasing perceived benefits and reducing perceived costs of behaviour change. Consequently, we propose a new framework which highlights suggested pathways for helping children initiate and sustain 'healthier' behaviours in order to inform future research and potentially childhood obesity intervention strategies.

Television viewing, television content, food intake, physical activity and body mass index: a cross-sectional study of preschool children aged 2-6 years.

ISSUE ADDRESSED: The mechanisms underlying the relationship between television (TV) viewing and weight status in preschool aged children are not well understood. This study aimed to explore the relationships between preschool children's TV viewing habits (i.e. time spent viewing, content watched and foods eaten while viewing), daily food intake, general physical activity levels and their body mass index (BMI). METHOD: A cross-sectional sample of preschool children in Melbourne (n = 135). Mothers of preschoolers completed a 3-day TV diary; information was collected on viewing time, content and food consumed while watching TV. Mothers also reported their child's height, weight and physical activity behaviour. Associations between study and outcome variables were determined by bivariate correlations and hierarchical regression analyses. RESULTS: Mean age of preschoolers was 4.5 years and 14% were overweight or obese. The mean daily time spent watching TV was 90.7 minutes (SD 50.7) A small, positive correlation was found between viewing TV on weekdays and child BMIz, (p<0.05). This effect was moderate when controlled for total kilojoules consumed while watching TV (on weekdays) and number of minutes spent in sedentary activities (across three days). CONCLUSIONS: This study suggests that TV viewing may affect preschool child weight status through displacement of physical activity or eating while viewing.

Substitution of a single residue in Stichodactyla helianthus peptide, ShK-Dap22, reveals a novel pharmacological profile.

ShK, a peptide isolated from Stichodactyla helianthus venom, blocks the voltage-gated potassium channels, K(v)1.1 and K(v)1.3, with similar high affinity. ShK-Dap(22), a synthetic derivative in which a diaminopropionic acid residue has been substituted at position Lys(22), has been reported to be a selective K(v)1.3 inhibitor and to block this channel with equivalent potency as ShK [Kalman et al. (1998) J. Biol. Chem. 273, 32697-32707]. In this study, a large body of evidence is presented which indicates that the potencies of wild-type ShK peptide for both K(v)1.3 and K(v)1.1 channels have been previously underestimated. Therefore, the affinity of ShK-Dap(22) for both channels appears to be ca. 10(2)-10(4)-fold weaker than ShK. ShK-Dap(22) does display ca. 20-fold selectivity for human K(v)1.3 vs K(v)1.1 when measured by the whole-cell voltage clamp method but not in equilibrium binding assays. ShK-Dap(22) has low affinity for K(v)1.2 channels, but heteromultimeric K(v)1.1-K(v)1.2 channels form a receptor with ca. 200-fold higher affinity for ShK-Dap(22) than K(v)1.1 homomultimers. In fact, K(v)1.1-K(v)1.2 channels bind ShK-Dap(22) with only ca. 10-fold less potency than ShK and reveal a novel pharmacology not predicted from the homomultimers of K(v)1.1 or K(v)1.2. The concentrations of ShK-Dap(22) needed to inhibit human T cell activation were ca. 10(3)-fold higher than those of ShK, in good correlation with the relative affinities of these peptides for inhibiting K(v)1.3 channels. All of these data, taken together, suggest that ShK-Dap(22) will not have the same in vivo immunosuppressant efficacy of other K(v)1.3 blockers, such as margatoxin or ShK. Moreover, ShK-Dap(22) may have undesired side effects due to its interaction with heteromultimeric K(v)1.1-K(v)1.2 channels, such as those present in brain and/or peripheral tissues.