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Background In 2017, the Canadian Partnership Against Cancer, a Canadian federally sponsored organisation, initiated a national multijurisdictional quality improvement (QI) initiative to maximise the use of synoptic data to drive cancer system improvements, known as the Evidence for Surgical Synoptic Quality Improvement Programme. The goal of our study was to evaluate the outcomes, determinants and learning of this nationally led initiative across six jurisdictions in Canada, integrating a mix of cancer surgery disease sites and clinicians.Methods A mixed-methods evaluation (surveys, semistructured interviews and focus groups) of this initiative was focused on the ability of each jurisdiction to use synoptic reporting data to successfully implement and sustain QI projects to beyond the completion of the initiative and the lessons learnt in the process. Resources provided to the jurisdictions included operational funding, training in QI methodology, national forums, expert coaches, and ad hoc monitoring and support. The programme emphasised foundational concepts of the QI process including data literacy, audit and feedback reports, communities of practice (CoP) and positive deviance methodology.Results 101 CoP meetings were held and 337 clinicians received feedback reports. There were 23 projects, and 22 of 23 (95%) showed improvements with 15 of 23 (65%) achieving the proposed targets. Enablers of effective data utilisation/feedback reports for QI included the need for clinicians to trust the data, have comparative data for feedback, and the engagement of both data scientists and clinicians in designing feedback reports. Enablers of sustainability of QI within each jurisdiction included QI training for clinicians, the ability to continue CoP meetings, executive and broad stakeholder engagement, and the ability to use pre-existing organisational infrastructures and processes. Barriers to continue QI work included lack of funding for core team members, lack of automated data collection processes and lack of clinician incentives (financial and other).Conclusion Success and sustainability in data-driven QI in cancer surgery require skills in QI methodology, data literacy and feedback, dedicated supportive personnel and an environment that promotes the process of collective learning and shared accountability. Building these capabilities in jurisdictional teams, tailoring interventions to facility contexts and strong leadership engagement will create the capacity for continued success in QI for cancer surgery.

In this paper, we summarize findings from the Tenth International Workshop on Tropical Cyclones (IWTC-10) subgroup on forecasting wind hazards and impacts. We found that new approaches to TC wind hazard forecasts continue to be developed and are becoming an increasingly common product offered by operational centres. To add greater context to wind risk information for users, many operational and research centres are also working to develop impact-based forecasts that incorporate hazard, vulnerability, and exposure data. Efforts to develop tropical cyclone wind impact forecasts present resourcing challenges, and when compared to wind hazard forecasting, are generally still in their infancy. Overall, both operational and research centres are extending significant efforts to meet the strong public need for accurate predictions of TC wind hazards and impacts around the world.

Abstract Background Across Ontario, since the year 2006 various knowledge translation (KT) interventions designed to improve the quality of rectal cancer surgery have been implemented by the provincial cancer agency or by individual researchers. Ontario is divided administratively into 14 health regions. We piloted a method to audit and score for each region of the province the KT interventions implemented to improve the quality of rectal cancer surgery. Methods We interviewed stakeholders to audit KT interventions used in respective regions over years 2006 to 2014. Results were summarized into narrative and visual forms. Using a modified Delphi approach, KT experts reviewed these data and then, for each region, scored implementation of KT interventions using a 20-item KT Signature Assessment Tool. Scores could range from 20 to 100 with higher scores commensurate with greater KT intervention implementation. Results There were thirty interviews. KT experts produced scores for each region that were bimodally distributed, with an average score for 2 regions of 78 (range 73–83) and for 12 regions of 30.5 (range 22–38). Conclusion Our methods efficiently identified two groups with similar KT Signature scores. Two regions had relatively high scores reflecting numerous KT interventions and the use of sustained iterative approaches in addition to those encouraged by the provincial cancer agency, while 12 regions had relatively low scores reflecting minimal activities outside of those encouraged by the provincial cancer agency. These groupings will be used for future comparative quantitative analyses to help determine if higher KT signature scores correlate with improved measures for quality of rectal cancer surgery.

Abstract Background In Ontario, FOLFIRINOX (FFX) and gemcitabine + nab‐paclitaxel (GnP) have been publicly funded for first‐line unresectable locally advanced pancreatic cancer (uLAPC) or metastatic pancreatic cancer (mPC) since April 2015. We examined the real‐world effectiveness and safety of FFX vs GnP for advanced pancreatic cancer, and in uLAPC and mPC. Methods Patients receiving first‐line FFX or GnP from April 2015 to March 2017 were identified in the New Drug Funding Program database. Baseline characteristics and outcomes were obtained through the Ontario Cancer Registry and other population‐based databases. Overall survival (OS) was assessed using Kaplan‐Meier and weighted Cox proportional hazard models, weighted by the inverse propensity score adjusting for baseline characteristics. Weighted odds ratio (OR) for hospitalization and emergency department visits (EDV) were estimated from weighted logistic regression models. Results For 1130 patients (632 FFX, 498 GnP), crude median OS was 9.6 and 6.1 months for FFX and GnP, respectively. Weighted OS was improved for FFX vs GnP (HR = 0.77, 0.70‐0.85). Less frequent EDV and hospitalization were observed in FFX (EDV: 67.8%; Hospitalization: 49.2%) than GnP (EDV: 77.7%; Hospitalization: 59.3%). More frequent febrile neutropenia‐related hospitalization was observed in FFX (5.8%) than GnP (3.3%). Risk of EDV and hospitalization were significantly lower for FFX vs GnP (EDV: OR = 0.68, P = .0001; Hospitalization: OR = 0.76, P = .002), whereas the risk of febrile neutropenia‐related hospitalization was significantly higher (OR = 2.12, P = .001). Outcomes for uLAPC and mPC were similar. Conclusion In the real world, FFX had longer OS, less frequent all‐cause EDV and all‐cause hospitalization, but more febrile neutropenia‐related hospitalization compared to GnP.

Prior research has characterized friendships, particularly long-distance friendships, as fragile. A turning point analysis compared changes in friendship levels for 100 college students in geographically-close (GC) and long-distance (LD) same-sex friendships. Results indicated that friendship level and commitment level are strongly and positively associated. Moreover, friendship level and proximity are interdependent with several categories of turning points. Finally, a linear sequence of shifts in friendship level is associated with both GC and LD friends, but a nonlinear sequence that includes a shift back to the casual friendship level with recovery is more typical for LD friends. Findings highlight transformation within friendships and suggest that it may be more accurate to conceptualize friendships as flexible rather than fragile. [ABSTRACT FROM AUTHOR]

Introduction Evidence on the effect of vasectomy and vasectomy reversal on risk of prostate cancer is conflicting, with the issue of detection bias a key criticism. In this study we examined the effect of vasectomy reversal on prostate cancer risk in a cohort of vasectomised men. Objectives and Approach A proof of concept study involving the International Population Data Linkage Network which pooled aggregated result data from participating centres in Australia, Canada and the United Kingdom. De-identified linked data extractions took place at each centre. Each participating centre locally conducted Cox proportional hazards regression analysis compared the risk of prostate cancer in those with/without vasectomy reversal in a cohort of vasectomised men. These results were then combined in a meta-analysis. Evidence of a protective effect of vasectomy reversal would suggest the harmful effect of vasectomy on prostate cancer risk, while nullifying detection bias. Results Data were received from Australia (the states of Western Australia and New South Wales), Canada (the province of Ontario), Wales and Scotland. In total, there were 9,754 men with vasectomy reversals, and 684,660 men with a vasectomy. The combined analysis showed no protective effect of vasectomy reversal on incidence of prostate cancer when compared to those who had vasectomy alone (HR, 95%CI: 0.92, 0.70-1.21). As such, the results align with previous studies which found little or no evidence of a link between vasectomy and prostate cancer. Conclusion/Implications The study, originally conceived at the first IPDLN meeting in London, found no obvious protective effect of vasectomy reversal on prostate cancer in vasectomised men. The project demonstrated the utility and feasibility of collaborative studies fostered through the IPDLN, despite methodological challenges faced when aggregating international data.

BACKGROUND: Postoperative surveillance following curative-intent resection of colorectal cancer (CRC) is variably performed due to existing guideline differences and to the limited data supporting different strategies.

Viral infections are ubiquitous in humans, animals, and plants. Real-time methods to identify viral infections are limited and do not exist for use in harsh or resource-constrained environments. Previous research identified that tissues produce unique volatile organic compounds (VOC) and demonstrated that VOC concentrations change during pathologic states including infection, neoplasia, or metabolic disease. Patterns of VOC expression may be pathogen-specific and may be associated with an odor that could be used for disease detection.We investigated the ability of two trained dogs to detect cell cultures infected with bovine viral diarrhea virus (BVDV) and to discriminate BVDV-infected cell cultures from uninfected cell cultures and from cell cultures infected with bovine herpes virus 1 (BHV 1) and bovine parainfluenza virus 3 (BPIV 3). Dogs were trained to recognize cell cultures infected with two different biotypes of BVDV propagated in MDBK cells using one of three culture media. For detection trials, one target and seven distractors were presented on a scent wheel by a dog handler unaware of the location of targets and distractors.Detection of BVDV- infected cell cultures by Dog 1 had a diagnostic sensitivity of 0.850 (95% CI: 0.701 - 0.942), which was lower than Dog 2 (0.967, 95% CI: 0.837 - 0.994). Both dogs exhibited very high diagnostic specificity (0.981, 95% CI: 0.960 - 0.993) and (0.993, 95% CI: 0.975 - 0.999), respectively.These findings demonstrate that trained dogs can differentiate between cultured cells infected with BVDV, BHV1, and BPIV3 and are a realistic real-time mobile pathogen sensing technology for viral pathogens. The ability to discriminate between target and distractor samples plausibly results from expression of unique VOC patterns virus-infected and uninfected cells.

The efficiency of visual tasks involving localization has traditionally been evaluated using forced choice experiments that capitalize on independence across locations to simplify the performance of the ideal observer. However, developments in ideal observer analysis have shown how an ideal observer can be defined for free-localization tasks, where a target can appear anywhere in a defined search region and subjects respond by localizing the target. Since these tasks are representative of many real-world search tasks, it is of interest to evaluate the efficiency of observer performance in them. The central question of this work is whether humans are able to effectively use the information in a free-localization task relative to a similar task where target location is fixed. We use a yes-no detection task at a cued location as the reference for this comparison. Each of the tasks is evaluated using a Gaussian target profile embedded in four different Gaussian noise backgrounds having power-law noise power spectra with exponents ranging from 0 to 3. The free localization task had a square 6.7° search region. We report on two follow-up studies investigating efficiency in a detect-and-localize task, and the effect of processing the white-noise backgrounds. In the fixed-location detection task, we find average observer efficiency ranges from 35% to 59% for the different noise backgrounds. Observer efficiency improves dramatically in the tasks involving localization, ranging from 63% to 82% in the forced localization tasks and from 78% to 92% in the detect-and- localize tasks. Performance in white noise, the lowest efficiency condition, was improved by filtering to give them a power-law exponent of 2. Classification images, used to examine spatial frequency weights for the tasks, show better tuning to ideal weights in the free-localization tasks. The high absolute levels of efficiency suggest that observers are well-adapted to free-localization tasks.

BACKGROUND: There is stigma attached to the identification of residents carrying antimicrobial resistant organisms (ARO) in long term care homes, yet there is a need to collect data about their prevalence for public health surveillance and intervention purposes. OBJECTIVE: We conducted a point prevalence study to assess ARO rates in long term care homes in Ontario using a secure data collection system. METHODS: All long term care homes in the province were asked to provide colonization or infection counts for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and extended-spectrum beta-lactamase (ESBL) as recorded in their electronic medical records, and the number of current residents. Data was collected online during the October-November 2011 period using a Paillier cryptosystem that allows computation on encrypted data. RESULTS: A provably secure data collection system was implemented. Overall, 82% of the homes in the province responded. MRSA was the most frequent ARO identified at 3 cases per 100 residents, followed by ESBL at 0.83 per 100 residents, and VRE at 0.56 per 100 residents. The microbiological findings and their distribution were consistent with available provincial laboratory data reporting test results for AROs in hospitals. CONCLUSIONS: We describe an ARO point prevalence study which demonstrated the feasibility of collecting data from long term care homes securely across the province and providing strong privacy and confidentiality assurances, while obtaining high response rates.

Available statistical preprocessing or quality control analysis tools for gene expression microarray datasets are known to greatly affect downstream data analysis, especially when degraded samples, unique tissue samples or novel expression assays are used. It is therefore important to assess the validity and impact of the assumptions built in to preprocessing schemes for a dataset. We developed and assessed a data preprocessing strategy for use with the Illumina DASL-based gene expression assay with partially degraded postmortem prefrontal cortex samples. The samples were obtained from individuals with autism as part of an investigation of the pathogenic factors contributing to autism.Using statistical analysis methods and metrics such as those associated with multivariate distance matrix regression (MDMR) and mean inter-array correlation, we developed a DASL-based assay gene expression preprocessing pipeline to accommodate and detect problems with microarray-based gene expression values obtained with degraded brain samples. Key steps in the pipeline included outlier exclusion, data transformation and normalization, and batch effect and covariate corrections. Our goal was to produce a clean dataset for subsequent downstream differential expression analysis. We ultimately settled on available transformation and normalization algorithms in the R/Bioconductor package lumi based on an assessment of their use in various combinations. A log2-transformed, quantile-normalized, and batch and seizure-corrected procedure was likely the most appropriate for our data. We empirically tested different components of our proposed preprocessing strategy and believe that our results suggest that a preprocessing strategy that effectively identifies outliers, normalizes the data, and corrects for batch effects, like ours can be applied to all studies, even those pursued with degraded samples.

BackgroundResearch has shown that people from higher socioeconomic status (SES) have better hepatocellular carcinoma (HCC) survival outcomes, although no such research has been carried out in Canada. We aimed to assess if an association between SES and HCC survival existed in the Canadian context.Methodology/principal findingsWe conducted a population-based cohort study linking HCC cases identified in the Ontario Cancer Registry between 1990 and 2009 to administrative and hospital data. Logistic regression and chi-squared tests were used to evaluate associations between SES (income quintile) and covariates. The Kaplan-Meier method was used to estimate survival. Sequential analysis of the proportional-hazards models were used to determine the association between SES and HCC survival controlling for potential prognostic covariates. During the period 1990-2009, 5,481 cases of HCC were identified. A significant association was found between SES and curative treatment (p = 0.0003), but no association was found between SES and non-curative treatment (p = 0.064), palliative treatment (p = 0.680), or ultrasound screening (p = 0.615). The median survival for the lowest SES was 8.5 months, compared to 8.8 months for the highest SES group. The age- and sex-adjusted proportional-hazards model showed statistically significant difference in HCC survival among the SES groups, with hazard ratio 0.905 (95% confidence intervals 0.821, 0.998) when comparing highest to lowest SES group. Further adjustments indicated that potentially curative treatment was the likely explanation for the association between SES and HCC survival.Conclusions/significanceOur findings suggest that a 10% HCC survival advantage exists for the higher SES groups. This association between SES and HCC survival is most likely a reflection of lack of access to care for low SES groups, revealing inequities in the Canadian healthcare system.

In order to monitor the effectiveness of HPV vaccination in Canada the linkage of multiple data registries may be required. These registries may not always be managed by the same organization and, furthermore, privacy legislation or practices may restrict any data linkages of records that can actually be done among registries. The objective of this study was to develop a secure protocol for linking data from different registries and to allow on-going monitoring of HPV vaccine effectiveness.A secure linking protocol, using commutative hash functions and secure multi-party computation techniques was developed. This protocol allows for the exact matching of records among registries and the computation of statistics on the linked data while meeting five practical requirements to ensure patient confidentiality and privacy. The statistics considered were: odds ratio and its confidence interval, chi-square test, and relative risk and its confidence interval. Additional statistics on contingency tables, such as other measures of association, can be added using the same principles presented. The computation time performance of this protocol was evaluated.The protocol has acceptable computation time and scales linearly with the size of the data set and the size of the contingency table. The worse case computation time for up to 100,000 patients returned by each query and a 16 cell contingency table is less than 4 hours for basic statistics, and the best case is under 3 hours.A computationally practical protocol for the secure linking of data from multiple registries has been demonstrated in the context of HPV vaccine initiative impact assessment. The basic protocol can be generalized to the surveillance of other conditions, diseases, or vaccination programs.

Protein factors bind ribosomes near the tunnel exit, facilitating protein trafficking and folding. In eukaryotes, the heterodimeric nascent polypeptide-associated complex (NAC) is the most abundant-equimolar to ribosomes. Saccharomyces cerevisiae has a minor β-type subunit (Nacβ2) in addition to abundant Nacβ1, and therefore two NAC heterodimers, α/β1 and α/β12. The additional beta NAC gene arose at the time of the whole genome duplication that occurred in the S. cerevisiae lineage. Nacβ2 has been implicated in regulating the fate of messenger RNA encoding ribosomal protein Rpl4 during translation via its interaction with the Caf130 subunit of the regulatory CCR4-Not complex. We found that Nacβ2 residues just C-terminal to the globular domain are required for its interaction with Caf130 and its negative effect on the growth of cells lacking Acl4, the specialized chaperone for Rpl4. Substitution of these Nacβ2 residues at homologous positions in Nacβ1 results in a chimeric protein that interacts with Caf130 and slows the growth of ∆acl4 cells lacking Nacβ2. Furthermore, alteration of residues in the N-terminus of Nacβ2 or chimeric Nacβ1 previously shown to affect ribosome binding overcomes the growth defect of ∆acl4. Our results are consistent with a model in which Nacβ2's ribosome association per se or its precise positioning is necessary for productive recruitment of CCR4-Not via its interaction with the Caf130 subunit to drive Rpl4 messenger RNA degradation., Competing Interests: Declarations of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Urinary hydroxylated-polycyclic aromatic hydrocarbons (PAHs), with half-life less than 2 days, are established biomarkers of short-term exposure to PAHs, a ubiquitous constituent of air pollution mixture. In this study, we explore the use of PAHs-hemoglobin adducts as biomarkers of longer-term exposure to air pollution by leveraging an extant resource of blood samples collected from 235 pregnant women residing in Rochester, NY. We measured red blood cells for benzo[ a ]pyrene-tetrols (BaPT) and phenanthrene-tetrols (PHET), both of which are hydrolysis products of PAH-hemoglobin adduct. We utilized previously estimated PM 2.5 and NO 2 concentrations within the 1 km 2 grid surrounding each participant's residence, calculated for up to 20 weeks before the blood collection date. Associations between PAHs tetrols and cumulative exposures to ambient PM 2.5 or NO 2 over different time periods were examined using a linear mixed-effects model with participant-specific random intercepts adjusting for season, gestation age, maternal age, maternal income level, and pre-pregnancy BMI. We observed positive associations between PHET concentration and cumulative PM 2.5 exposure over gestational weeks 12-17, and between BaPT concentration and cumulative PM 2.5 exposure over gestational weeks 3-16 prior to sample collection. Each interquartile range (IQR) increase in 14 week PM 2.5 exposure (1.26 μg m -3 ) was associated with a 9.02% (95% CI: 0.30%, 17.7%) increase in PHET and a 12.8% (95% CI: 1.09%, 23.5%) increase in BaPT levels. In contrast, no associations were observed between either biomarker and cumulative NO 2 exposures. These findings underscore the potential of PAH-hemoglobin adducts as longer-term (weeks to 4 months) exposure biomarkers of ambient PM 2.5 .

This study investigates the potential of the Threshold of Toxicological Concern (TTC) as an alternative to traditional animal testing in pesticide regulatory risk assessments. The TTC is a principle that establishes exposure threshold values for chemicals with certain structural features, below which there is no appreciable risk to human health. A case study was conducted with α-terpineol, an inert ingredient proposed to be used at low concentrations in pesticide products, to compare a conventional risk assessment using animal data with one using the TTC method. For the conventional risk assessment, animal data showed that there was no toxicity endpoint of concern, which resulted in a qualitative assessment and no risks of concern identified. For the risk assessment using the TTC method, a 5th percentile no-observed-effect level (NOEL) selected based on α-terpineol's Cramer classification was used as a point of departure (POD) for a quantitative risk assessment that resulted in no risks of concern identified. Therefore, the same conclusion was reached with both approaches and α-terpineol is considered safe for use in pesticide products at low concentrations. A comparative analysis was also performed to determine the applicability of the TTC method in calculating potential dietary risk from common pesticide use patterns for chemicals that fall within different Cramer classes. Results showed that use of the TTC method may be feasible for inert ingredient risk assessments when chemicals are used in a pesticide product at concentrations below 1%. This research underscores the TTC as a valuable and robust tool for assessing the potential hazards from inert ingredient use in pesticide formulations, considering factors such as chemical properties and the concentrations at which a chemical may be used in pesticide products. These findings contribute to the ongoing efforts by the United States Environmental Protection Agency (US EPA) to reduce animal testing in chemical safety assessments. The TTC method presents a viable alternative for risk evaluations of chemicals used at low concentrations, with anticipated low exposure, and with a predicted low toxicity potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Restricted fetal growth (RFG) is a leading contributor to perinatal mortality and has been associated with gestational exposure to air pollution, such as fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), and polycyclic aromatic hydrocarbons (PAHs). This study examines the association between trimester-specific and weekly means of air pollution throughout gestation and placental inflammatory markers at delivery. In a prospective cohort study of 263 pregnant women in Rochester, NY, we measured interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in placental tissue and estimated gestational exposure to PM 2.5 and NO 2 using a high-resolution spatial-temporal model. Exposure to PAHs was estimated using urinary 1-hydroxypyrene (1-OHP) concentrations collected once per trimester. Using distributed lag models with a penalized spline function, each interquartile range (2.6 μg/m 3 ) increase in PM 2.5 concentration during gestational weeks 6-11 was associated with decreased placental IL-6 levels (-22.2%, 95% CI: -39.0%, -0.64%). Using multiple linear regression models, each interquartile range increase of 1-OHP was associated with an increase in TNF-α in the first trimester (58.5%, 95% CI: 20.7%, 74.2%), third trimester (22.9%, 95% CI: 0.04%, 49.5%), and entire pregnancy (29.6%, 95%CI: 3.9%,60.6%). Our results suggest gestational exposure to air pollution may alter the inflammatory environment of the placenta at delivery., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Co-published by Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, and American Chemical Society.)

J-domain proteins are critical Hsp70 co-chaperones. A and B types have a poorly understood glycine-rich region (G rich ) adjacent to their N-terminal J-domain (J dom ). We analyzed the ability of J dom /G rich segments of yeast Class B Sis1 and a suppressor variant of Class A, Ydj1, to rescue the inviability of sis1-∆. In each, we identified a cluster of G rich residues required for rescue. Both contain conserved hydrophobic and acidic residues and are predicted to form helices. While, as expected, the Sis1 segment docks on its J-domain, that of Ydj1 does not. However, data suggest both interact with Hsp70. We speculate that the G rich -Hsp70 interaction of Classes A and B J-domain proteins can fine tune the activity of Hsp70, thus being particularly important for the function of Class B., (© 2024 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Among the six known iron‑sulfur (FeS) cluster biogenesis machineries that function across all domains of life only one involves a molecular chaperone system. This machinery, called ISC for 'iron sulfur cluster', functions in bacteria and in mitochondria of eukaryotes including humans. The chaperone system - a dedicated J-domain protein co-chaperone termed Hsc20 and its Hsp70 partner - is essential for proper ISC machinery function, interacting with the scaffold protein IscU which serves as a platform for cluster assembly and subsequent transfer onto recipient apo-proteins. Despite many years of research, surprisingly little is known about the specific role(s) that the chaperones play in the ISC machinery. Here we review three non-exclusive scenarios that range from involvement of the chaperones in the cluster transfer to regulation of the cellular levels of IscU itself., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationship that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

J-domain proteins (JDPs) are obligate cochaperones of Hsp70s. The Class A JDP Apj1 of the yeast cytosol has an unusually complex region between the N-terminal J-domain and the substrate binding region-often called the G rich or GF region in Class A and B JDPs because of its typical abundance of glycine. The N-terminal 161-residue Apj1 fragment is known to be sufficient for Apj1 function in prion curing, driven by the overexpression of Hsp104. Further analyzing the N-terminal segment of Apj1, we found that a 90-residue fragment that includes the 70-residue J-domain and the adjacent 12-residue glutamine/alanine (Q/A) segment is sufficient for curing. Furthermore, the 121-residue fragment that includes the G rich region was sufficient to not only sustain the growth of cells lacking the essential Class B JDP Sis1 but also enabled the maintenance of several prions normally dependent on Sis1 for propagation. A J-domain from another cytosolic JDP could substitute for the Sis1-related functions but not for Apj1 in prion curing. Together, these results separate the functions of JDPs in prion biology and underscore the diverse functionality of multi-domain cytosolic JDPs in yeast., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ganser, McNish, Schwanitz, Delaney, Corpus, Schilke, Biswal, Sahi, Craig and Hines.)

The area surrounding the tunnel exit of the 60S ribosomal subunit is a hub for proteins involved in maturation and folding of emerging nascent polypeptide chains. How different factors vie for positioning at the tunnel exit in the complex cellular environment is not well understood. We used in vivo site-specific cross-linking to approach this question, focusing on two abundant factors-the nascent chain-associated complex (NAC) and the Hsp70 chaperone system that includes the J-domain protein co-chaperone Zuotin. We found that NAC and Zuotin can cross-link to each other at the ribosome, even when translation initiation is inhibited. Positions yielding NAC-Zuotin cross-links indicate that when both are present the central globular domain of NAC is modestly shifted from the mutually exclusive position observed in cryogenic electron microscopy analysis. Cross-linking results also suggest that, even in NAC's presence, Hsp70 can situate in a manner conducive for productive nascent chain interaction-with the peptide binding site at the tunnel exit and the J-domain of Zuotin appropriately positioned to drive stabilization of nascent chain binding. Overall, our results are consistent with the idea that, in vivo, the NAC and Hsp70 systems can productively position on the ribosome simultaneously., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Introduction: There is a lack of information about the experiences of people living with dementia and their carers, especially in rural and regional areas. Understanding these experiences helps to identify gaps and unmet needs within the health system and improve quality of care and outcomes for people living with dementia. The aim of this study was to improve our knowledge of dementia support needs. This included access to health and social care services and supports for people living with dementia and those who provide informal or formal support to someone living with dementia., Methods: Interviews were conducted with 26 participants from the Gippsland region of Victoria, Australia with knowledge of dementia care. Purposive sampling engaged people with lived experience, carers/family members and health professionals delivering dementia care and social services. Discussions centred around participants' experiences of support services, the diagnosis process and what they thought was needed to improve the services and supports offered. Thematic analysis of the data was undertaken using the framework method., Results: The interview data indicated that the needs of many people living with dementia and their carers were not currently being met. The themes were limited access to services and supports, including primary and specialist care, often impacted by lack of knowledge of care options, difficulty navigating the system and funding models as a barrier, leading to delays in getting a diagnosis and accessing specialist services; lack of holistic care to enable people living with dementia to 'live well'; and stigma impacted by a lack of knowledge of dementia among professionals and in the community. Relationship-centred care was described as a way to improve the lives of people living with dementia., Conclusion: Key areas for improvement include increasing community awareness of dementia and available local services, more support to obtain an early dementia diagnosis, increased help to navigate the system, especially immediately after diagnosis, and easier access to appropriate home support services when they are needed. Other recommendations include person-centred care across settings - supported by funding models, more education and communication skills training for health professionals and care staff - and greater support for and increased recognition of carers.

Hsp70 are ubiquitous, versatile molecular chaperones that cyclically interact with substrate protein(s). The initial step requires synergistic interaction of a substrate and a J-domain protein (JDP) cochaperone, via its J-domain, with Hsp70 to stimulate hydrolysis of its bound ATP. This hydrolysis drives conformational changes in Hsp70 that stabilize substrate binding. However, because of the transient nature of substrate and JDP interactions, this key step is not well understood. Here we leverage a well characterized Hsp70 system specialized for iron-sulfur cluster biogenesis, which like many systems, has a JDP that binds substrate on its own. Utilizing an ATPase-deficient Hsp70 variant, we isolated a Hsp70-JDP-substrate tripartite complex. Complex formation and stability depended on residues previously identified as essential for bipartite interactions: JDP-substrate, Hsp70-substrate and J-domain-Hsp70. Computational docking based on the established J-domain-Hsp70(ATP) interaction placed the substrate close to its predicted position in the peptide-binding cleft, with the JDP having the same architecture as when in a bipartite complex with substrate. Together, our results indicate that the structurally rigid JDP-substrate complex recruits Hsp70(ATP) via precise positioning of J-domain and substrate at their respective interaction sites - resulting in functionally high affinity (i.e., avidity). The exceptionally high avidity observed for this specialized system may be unusual because of the rigid architecture of its JDP and the additional JDP-Hsp70 interaction site uncovered in this study. However, functionally important avidity driven by JDP-substrate interactions is likely sufficient to explain synergistic ATPase stimulation and efficient substrate trapping in many Hsp70 systems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Military deployment and reintegration challenges permeate the lives and relationships of Veterans, their spouses, and their families. Among these challenges, 23% of post-9/11 Veterans have been diagnosed with posttraumatic stress disorder (PTSD). Psychiatric service dogs have been found to help clinically alleviate PTSD symptoms when used as a complementary intervention. However, minimal research exists that explores the role of the service dog as a mechanism for cultivating resilience within the military family system. Researchers utilized a qualitative, constant comparative approach to analyze self-reported experiences of 101 individuals, including Veterans ( n = 67) and their spouses ( n = 34). Analyzed through the framework of the Theory of Resilience and Relational Load (Afifi et al., 2016), findings suggest complex communication processes that facilitate relational and family adaptation. These processes encompassed (a) the role of the service dog in building emotional reserves, (b) relational load introduced when caring for the service dog, and (c) the service dog's facilitation of relational maintenance behaviors among family members that contributed to communal orientation. Based on the results of this qualitative analysis, researchers suggest educational interventions where service dog trainers and mental health practitioners can incorporate relational maintenance strategies and family-focused approaches to integrating service dogs as military family members., Competing Interests: Conflict of Interest The authors have no conflicts of interest to disclose.

There is a growing body of evidence supporting the use of telehealth to provide parent training in behaviour analytic interventions and researchers have begun to focus on international demonstrations of this model. The current study assessed the efficacy of a training package focused on naturalistic teaching strategies designed to upskill parents of children with autism spectrum disorder and provide them with ready to use strategies to increase social communication behaviours across verbal operants. Two parent-child dyads were trained to increase mand, tact and intraverbals during play. Parents displayed increases in fidelity for each strategy and viewed the training favourably. Both children showed gains across verbal operants, as captured by a multiple baseline across behaviours design., Supplementary Information: The online version contains supplementary material available at 10.1007/s10882-022-09859-4., Competing Interests: Conflict of InterestThe authors declare no conflict of interest., (© The Author(s) 2022.)

Mitochondrial J-domain protein (JDP) co-chaperones orchestrate the function of their Hsp70 chaperone partner(s) in critical organellar processes that are essential for cell function. These include folding, refolding, and import of mitochondrial proteins, maintenance of mitochondrial DNA, and biogenesis of iron-sulfur cluster(s) (FeS), prosthetic groups needed for function of mitochondrial and cytosolic proteins. Consistent with the organelle's endosymbiotic origin, mitochondrial Hsp70 and the JDPs' functioning in protein folding and FeS biogenesis clearly descended from bacteria, while the origin of the JDP involved in protein import is less evident. Regardless of their origin, all mitochondrial JDP/Hsp70 systems evolved unique features that allowed them to perform mitochondria-specific functions. Their modes of functional diversification and specialization illustrate the versatility of JDP/Hsp70 systems and inform our understanding of system functioning in other cellular compartments., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

This study evaluates the effectiveness of a brief functional analysis and functional communication training conducted via telehealth. Three interventionist-child dyads took part in the study including one speech and language pathologist and two school teaching assistants, each working with one child with autism spectrum disorder. Interventionists were trained using didactic training to implement a brief functional analysis as well as synchronous coaching from a BCBA ® to implement functional communication training. A multiple baseline across participants design was utilised to evaluate if interventionists could implement functional communication training to decrease challenging behaviours that included aggression, elopement and disruption. Sessions concluded earlier than planned due to school closures mandated by the COVID-19 outbreak for two of the three participants; however, existing data provide evidence that telehealth is a valid model for enabling clinicians to work in collaboration with school personnel to effectively deliver assessment and intervention procedures remotely via telehealth., Competing Interests: Conflicts of InterestThe authors have no conflicts of interest to disclose that are relevant to the contents of this article., (© The Author(s) 2022.)

In cells molecular chaperone systems consisting of Hsp70 and its obligatory J-domain protein (JDP) co-chaperones transiently interact with a myriad of client proteins-with JDPs typically recruiting their partner Hsp70 to interact with particular clients. The fundamentals of this cyclical interactions between JDP/Hsp70 systems and clients are well established. Much less is known about other aspects of JDP/Hsp70 system function, including how such systems evolved over time. Here we discuss the JDP/Hsp70 system involved in the biogenesis of iron-sulfur (FeS) clusters. Interaction between the client protein, the scaffold on which clusters are built, and its specialized JDP Hsc20 has stayed constant. However, the system's Hsp70 has changed at least twice. In some species Hsc20's Hsp70 partner interacts only with the scaffold, in others it has many JDP partners in addition to Hsc20 and interacts with many client proteins. Analysis of this switching of Hsp70 partners has provided insight into the insulation of JDP/Hsp70 systems from one another that can occur when more than one Hsp70 is present in a cellular compartment, as well as how competition among JDPs is balanced when an Hsp70 partner is shared amongst a number of JDPs. Of particularly broad relevance, even though the scaffold's interactions with Hsc20 and Hsp70 are functionally critical for the biogenesis of FeS cluster-containing proteins, it is the modulation of the Hsc20-Hsp70 interaction per se that allows Hsc20 to function with such different Hsp70 partners., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Marszalek and Craig.)

J-domain protein cochaperones drive much of the functional diversity of Hsp70-based chaperone systems. Sis1 is the only essential J-domain protein of the cytosol/nucleus of Saccharomyces cerevisiae . Why it is required for cell growth is not understood, nor how critical its role is in regulation of heat shock transcription factor 1 (Hsf1). We report that single-residue substitutions in Tti1, a component of the heterotrimeric TTT complex, a specialized chaperone system for phosphatidylinositol 3-kinase-related kinase (PIKK) proteins, allow growth of cells lacking Sis1. Upon depletion of Sis1, cells become hypersensitive to rapamycin, a specific inhibitor of TORC1 kinase. In addition, levels of the three essential PIKKs (Mec1, Tra1, and Tor2), as well as Tor1, decrease upon Sis1 depletion. Overexpression of Tti1 allows growth without an increase in the other subunits of the TTT complex, Tel2 and Tti2, suggesting that it can function independent of the complex. Cells lacking Sis1, with viability supported by Tti1 suppressor, substantially up-regulate some, but not all, heat shock elements activated by Hsf1. Together, our results suggest that Sis1 is required as a cochaperone of Hsp70 for the folding/maintenance of PIKKs, making Sis1 an essential gene, and its requirement for Hsf1 regulation is more nuanced than generally appreciated.

In mitochondria, cysteine desulfurase (Nfs1) plays a central role in the biosynthesis of iron-sulfur (FeS) clusters, cofactors critical for activity of many cellular proteins. Nfs1 functions both as a sulfur donor for cluster assembly and as a binding platform for other proteins functioning in the process. These include not only the dedicated scaffold protein (Isu1) on which FeS clusters are synthesized but also accessory FeS cluster biogenesis proteins frataxin (Yfh1) and ferredoxin (Yah1). Yfh1 has been shown to activate cysteine desulfurase enzymatic activity, whereas Yah1 supplies electrons for the persulfide reduction. While Yfh1 interaction with Nfs1 is well understood, the Yah1-Nfs1 interaction is not. Here, based on the results of biochemical experiments involving purified WT and variant proteins, we report that in Saccharomyces cerevisiae, Yah1 and Yfh1 share an evolutionary conserved interaction site on Nfs1. Consistent with this notion, Yah1 and Yfh1 can each displace the other from Nfs1 but are inefficient competitors when a variant with an altered interaction site is used. Thus, the binding mode of Yah1 and Yfh1 interacting with Nfs1 in mitochondria of S. cerevisiae resembles the mutually exclusive binding of ferredoxin and frataxin with cysteine desulfurase reported for the bacterial FeS cluster assembly system. Our findings are consistent with the generally accepted scenario that the mitochondrial FeS cluster assembly system was inherited from bacterial ancestors of mitochondria., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interests with the content of this article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Interventions based upon applied behaviour analysis (ABA) have been shown to be best practice for children with autism spectrum disorder. However, in many parts of the world there is a shortage of appropriately trained behaviour analysts. Telehealth is a potential solution to increasing access to ABA. Our study assessed the use of telehealth to provide parent training in naturalistic teaching strategies designed to increase child communication skills. Five parent child dyads took part in the training, utilising didactic training and synchronous coaching. Parents could be trained to a high level of fidelity and viewed the training favourably. Children showed variable gains in communication and improved positive affect. The project was cost effective in comparison with traditional training models., Competing Interests: The authors declare no conflict of interest., (© The Author(s) 2022, corrected publication 2022.)

Experiencing trauma can lead to a variety of chronic and acute symptoms, including post- traumatic stress disorder (PTSD), anxiety, depression, substance abuse, and poor social skills. Given the variety of causes for trauma incorporating individualized treatment options is important for efficacy. Equine assisted mental health (EAMH) - a team approach incorporating equines, clients, and practitioners - has been successful in treating those who have experienced trauma, including veterans and individuals with PTSD, at-risk youth, victims of sexual violence, and children who have been neglected. Although researchers and practitioners understand some about how EAMH treatment results in positive outcomes for these individuals, little is known about the communicative processes that support them. The current study included 19 in-depth interviews with EAMH therapists and practitioners to explore the role of equine communication (i.e., congruence, ongoing positive regard, and empathy) as a communicative process that is integral to the facilitation of EAMH as individualized therapeutic treatment. Using tenets of patient-centered communication (PCC) and principles of client-centered therapy, implications for human-horse communication in therapeutic contexts and client-centered care are discussed.

In eukaryotes, an Hsp70 molecular chaperone triad assists folding of nascent chains emerging from the ribosome tunnel. In fungi, the triad consists of canonical Hsp70 Ssb, atypical Hsp70 Ssz1 and J-domain protein cochaperone Zuo1. Zuo1 binds the ribosome at the tunnel exit. Zuo1 also binds Ssz1, tethering it to the ribosome, while its J-domain stimulates Ssb's ATPase activity to drive efficient nascent chain interaction. But the function of Ssz1 and how Ssb engages at the ribosome are not well understood. Employing in vivo site-specific crosslinking, we found that Ssb(ATP) heterodimerizes with Ssz1. Ssb, in a manner consistent with the ADP conformation, also crosslinks to ribosomal proteins across the tunnel exit from Zuo1. These two modes of Hsp70 Ssb interaction at the ribosome suggest a functionally efficient interaction pathway: first, Ssb(ATP) with Ssz1, allowing optimal J-domain and nascent chain engagement; then, after ATP hydrolysis, Ssb(ADP) directly with the ribosome., (© 2021. The Author(s).)

J-domain proteins (JDPs), obligatory Hsp70 cochaperones, play critical roles in protein homeostasis. They promote key allosteric transitions that stabilize Hsp70 interaction with substrate polypeptides upon hydrolysis of its bound ATP. Although a recent crystal structure revealed the physical mode of interaction between a J-domain and an Hsp70, the structural and dynamic consequences of J-domain action once bound and how Hsp70s discriminate among its multiple JDP partners remain enigmatic. We combined free energy simulations, biochemical assays and evolutionary analyses to address these issues. Our results indicate that the invariant aspartate of the J-domain perturbs a conserved intramolecular Hsp70 network of contacts that crosses domains. This perturbation leads to destabilization of the domain-domain interface-thereby promoting the allosteric transition that triggers ATP hydrolysis. While this mechanistic step is driven by conserved residues, evolutionarily variable residues are key to initial JDP/Hsp70 recognition-via electrostatic interactions between oppositely charged surfaces. We speculate that these variable residues allow an Hsp70 to discriminate amongst JDP partners, as many of them have coevolved. Together, our data points to a two-step mode of J-domain action, a recognition stage followed by a mechanistic stage., Competing Interests: The authors have declared that no competing interests exist.

Mitochondria play a central role in the biogenesis of iron-sulfur cluster(s) (FeS), protein cofactors needed for many cellular activities. After assembly on scaffold protein Isu, the cluster is transferred onto a recipient apo-protein. Transfer requires Isu interaction with an Hsp70 chaperone system that includes a dedicated J-domain protein co-chaperone (Hsc20). Hsc20 stimulates Hsp70's ATPase activity, thus stabilizing the critical Isu-Hsp70 interaction. While most eukaryotes utilize a multifunctional mitochondrial (mt)Hsp70, yeast employ another Hsp70 (Ssq1), a product of mtHsp70 gene duplication. Ssq1 became specialized in FeS biogenesis, recapitulating the process in bacteria, where specialized Hsp70 HscA cooperates exclusively with an ortholog of Hsc20. While it is well established that Ssq1 and HscA converged functionally for FeS transfer, whether these two Hsp70s possess similar biochemical properties was not known. Here, we show that overall HscA and Ssq1 biochemical properties are very similar, despite subtle differences being apparent - the ATPase activity of HscA is stimulated to a somewhat higher levels by Isu and Hsc20, while Ssq1 has a higher affinity for Isu and for Hsc20. HscA/Ssq1 are a unique example of biochemical convergence of distantly related Hsp70s, with practical implications, crossover experimental results can be combined, facilitating understanding of the FeS transfer process.

The J-domain protein Zuotin is a multi-domain eukaryotic Hsp70 co-chaperone. Though it is primarily ribosome-associated, positioned at the exit of the 60S subunit tunnel where it promotes folding of nascent polypeptide chains, Zuotin also has off-ribosome functions. Domains of Zuotin needed for 60S association and interaction with Hsp70 are conserved in eukaryotes. However, whether the 4-helix bundle (4HB) domain is conserved remains an open question. We undertook evolutionary and structural approaches to clarify this issue. We found that the 4HB segment of human Zuotin also forms a bundle of 4 helices. The positive charge of Helix I, which in Saccharomyces cerevisiae is responsible for interaction with the 40S subunit, is particularly conserved. However, the C-termini of fungal and human 4HBs are not similar. In fungi the C-terminal segment forms a plug that folds back into the bundle; in S. cerevisiae it plays an important role in bundle stability and, off the ribosome, in transcriptional activation. In human, C-terminal helix IV of the 4HB is extended, protruding from the bundle. This extension serves as a linker to the regulatory SANT domains, which are present in animals, plants and protists, but not fungi. Further analysis of Zuotin sequences revealed that the plug likely arose as a result of genomic rearrangement upon SANT domain loss early in the fungal lineage. In the lineage leading to S. cerevisiae, the 4HB was subjected to positive selection with the plug becoming increasingly hydrophobic. Eventually, these hydrophobic plug residues were coopted for a novel regulatory function-activation of a recently emerged transcription factor, Pdr1. Our data suggests that Zuotin evolved off-ribosome functions twice-once involving SANT domains, then later in fungi, after SANT domain loss, by coopting the hydrophobic plug. Zuotin serves as an example of complex intertwining of molecular chaperone function and cell regulation., Competing Interests: The authors have declared that no competing interests exist.

Interventions based on applied behaviour analysis are considered evidence based practice for autism spectrum disorders. Due to the shortage of highly qualified professionals required for their delivery, innovative models should be explored, such as telehealth. Telehealth utilises technology for remote training and supervision. The purpose of our study was to systematically review the literature researching telehealth and ABA. We analysed intervention characteristics, outcomes and research quality in 28 studies and identified gaps. Intervention characteristics were: (1) research design (2) participants (3) technology (4) dependent variables (5) aims. Outcomes were favourable with all studies reporting improvements in at least one variable. Quality ratings were significantly low. Implications for future research and practice are discussed in light of identified methodological downfalls.

Efficient movement of proteins across membranes is required for cell health. The translocation process is particularly challenging when the channel in the membrane through which proteins must pass is narrow-such as those in the membranes of the endoplasmic reticulum and mitochondria. Hsp70 molecular chaperones play roles on both sides of these membranes, ensuring efficient translocation of proteins synthesized on cytosolic ribosomes into the interior of these organelles. The "import motor" in the mitochondrial matrix, which is essential for driving the movement of proteins across the mitochondrial inner membrane, is arguably the most complex Hsp70-based system in the cell.

By binding to a multitude of polypeptide substrates, Hsp70-based molecular chaperone systems perform a range of cellular functions. All J-protein co-chaperones play the essential role, via action of their J-domains, of stimulating the ATPase activity of Hsp70, thereby stabilizing its interaction with substrate. In addition, J-proteins drive the functional diversity of Hsp70 chaperone systems through action of regions outside their J-domains. Targeting to specific locations within a cellular compartment and binding of specific substrates for delivery to Hsp70 have been identified as modes of J-protein specialization. To better understand J-protein specialization, we concentrated on Saccharomyces cerevisiae SIS1, which encodes an essential J-protein of the cytosol/nucleus. We selected suppressors that allowed cells lacking SIS1 to form colonies. Substitutions changing single residues in Ydj1, a J-protein, which, like Sis1, partners with Hsp70 Ssa1, were isolated. These gain-of-function substitutions were located at the end of the J-domain, suggesting that suppression was connected to interaction with its partner Hsp70, rather than substrate binding or subcellular localization. Reasoning that, if YDJ1 suppressors affect Ssa1 function, substitutions in Hsp70 itself might also be able to overcome the cellular requirement for Sis1, we carried out a selection for SSA1 suppressor mutations. Suppressing substitutions were isolated that altered sites in Ssa1 affecting the cycle of substrate interaction. Together, our results point to a third, additional means by which J-proteins can drive Hsp70's ability to function in a wide range of cellular processes-modulating the Hsp70-substrate interaction cycle.

Hsp70 chaperone machineries have pivotal roles in an array of fundamental biological processes through their facilitation of protein folding, disaggregation, and remodeling. The obligate J-protein co-chaperones of Hsp70s drive much of this remarkable multifunctionality, with most Hsp70s having multiple J-protein partners. Recent data suggest that J-protein-driven versatility is substantially due to precise localization within the cell and the specificity of substrate protein binding. However, this relatively simple view belies the intricacy of J-protein function. Examples are emerging of J-protein interactions with Hsp70s and other chaperones, as well as integration into broader cellular networks. These interactions fine-tune, in critical ways, the ability of Hsp70s to participate in diverse cellular processes., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Proteins destined for the mitochondrial matrix are targeted to the inner membrane Tim17/23 translocon by their presequences. Inward movement is driven by the matrix-localized, Hsp70-based motor. The scaffold Tim44, interacting with the matrix face of the translocon, recruits other motor subunits and binds incoming presequence. The basis of these interactions and their functional relationships remains unclear. Using site-specific in vivo crosslinking and genetic approaches in Saccharomyces cerevisiae , we found that both domains of Tim44 interact with the major matrix-exposed loop of Tim23, with the C-terminal domain (CTD) binding Tim17 as well. Results of in vitro experiments showed that the N-terminal domain (NTD) is intrinsically disordered and binds presequence near a region important for interaction with Hsp70 and Tim23. Our data suggest a model in which the CTD serves primarily to anchor Tim44 to the translocon, whereas the NTD is a dynamic arm, interacting with multiple components to drive efficient translocation.

Though toxic in excess, iron is vital for life. Thus, its use in all cells is tightly regulated. Analysis of Saccharomyces cerevisiae, which has been used extensively as a model system, has revealed layers of regulation of cellular iron trafficking and utilization. This regulation is based on the availability of both elemental iron and functionality of the Fe-S cluster biogenesis system. Here, we discuss a possible "first responder" regulatory mechanism centered on the stability of the scaffold protein on which Fe-S clusters are built.

Hsp70 chaperones and their obligatory J-protein cochaperones function together in many cellular processes. Via cycles of binding to short stretches of exposed amino acids on substrate proteins, Hsp70/J-protein chaperones not only facilitate protein folding but also drive intracellular protein transport, biogenesis of cellular structures, and disassembly of protein complexes. The biogenesis of iron-sulfur (Fe-S) clusters is one of the critical cellular processes that require Hsp70/J-protein action. Fe-S clusters are ubiquitous cofactors critical for activity of proteins performing diverse functions in, for example, metabolism, RNA/DNA transactions, and environmental sensing. This biogenesis process can be divided into two sequential steps: first, the assembly of an Fe-S cluster on a conserved scaffold protein, and second, the transfer of the cluster from the scaffold to a recipient protein. The second step involves Hsp70/J-protein chaperones. Via binding to the scaffold, chaperones enable cluster transfer to recipient proteins. In eukaryotic cells mitochondria have a key role in Fe-S cluster biogenesis. In this review, we focus on methods that enabled us to dissect protein interactions critical for the function of Hsp70/J-protein chaperones in the mitochondrial process of Fe-S cluster biogenesis in the yeast Saccharomyces cerevisiae., (© 2017 Elsevier Inc. All rights reserved.)