60 research outputs found

    Sumoylation of The Budding Yeast Kinetochore Protein Ndc10 is Required for Ndc10 Spindle Localization and Regulation of Anaphase Spindle Elongation

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    Posttranslational modification by the ubiquitin-like protein SUMO (small ubiquitin-like modifier) is emerging as an important regulator in many cellular processes, including genome integrity. In this study, we show that the kinetochore proteins Ndc10, Bir1, Ndc80, and Cep3, which mediate the attachment of chromosomes to spindle microtubules, are sumoylated substrates in budding yeast. Furthermore, we show that Ndc10, Bir1, and Cep3 but not Ndc80 are desumoylated upon exposure to nocodazole, highlighting the possibility of distinct roles for sumoylation in modulating kinetochore protein function and of a potential link between the sumoylation of kinetochore proteins and mitotic checkpoint function. We find that lysine to arginine mutations that eliminate the sumoylation of Ndc10 cause chromosome instability, mislocalization of Ndc10 from the mitotic spindle, abnormal anaphase spindles, and a loss of Bir1 sumoylation. These data suggest that sumoylation of Ndc10 and other kinetochore proteins play a critical role during the mitotic process

    Semantic descriptor for intelligence services

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    The exposition and discovery of intelligence especially for connected devices and autonomous systems have become an important area of the research towards an all-intelligent world. In this article, it a semantic description of functions is proposed and used to provide intelligence services mainly for networked devices. The semantic descriptors aim to provide interoperability between multiple domains' vocabularies, data models, and ontologies, so that device applications become able to deploy them autonomously once they are onboarded in the device or system platform. The proposed framework supports the discovery, onboarding, and updating of the services by providing descriptions of their execution environment, software dependencies, policies and data inputs required, as well as the outputs produced, to enable application decoupling from the AI functions

    P(I) Release Limits the Intrinsic and RNA-Stimulated ATPase Cycles of DEAD-Box Protein 5 (Dbp5).

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    mRNA export from the nucleus depends on the ATPase activity of the DEAD-box protein Dbp5/DDX19. Although Dbp5 has measurable ATPase activity alone, several regulatory factors (e.g., RNA, nucleoporin proteins, and the endogenous small molecule InsP6) modulate catalytic activity in vitro and in vivo to facilitate mRNA export. An analysis of the intrinsic and regulator-activated Dbp5 ATPase cycle is necessary to define how these factors control Dbp5 and mRNA export. Here, we report a kinetic and equilibrium analysis of the Saccharomyces cerevisiae Dbp5 ATPase cycle, including the influence of RNA on Dbp5 activity. These data show that ATP binds Dbp5 weakly in rapid equilibrium with a binding affinity (KT~4 mM) comparable to the KM for steady-state cycling, while ADP binds an order of magnitude more tightly (KD~0.4 mM). The overall intrinsic steady-state cycling rate constant (kcat) is limited by slow, near-irreversible ATP hydrolysis and even slower subsequent phosphate release. RNA increases kcat and rate-limiting Pi release 20-fold, although Pi release continues to limit steady-state cycling in the presence of RNA, in conjunction with RNA binding. Together, this work identifies RNA binding and Pi release as important biochemical transitions within the Dbp5 ATPase cycle and provides a framework for investigating the means by which Dbp5 and mRNA export is modulated by regulatory factors.E.V.W. is supported by National Science Foundation Graduate Research Fellowship No. DGE-1122492 and J.V. is supported by an Alberta Innovates Health Solutions Postdoctoral Fellowship. M.M. and Y.M. were supported by a Senior Research Fellowship from the Wellcome Trust (101908/Z/13/Z) and by National Institutes of Health grant R01 GM102869. Research support for B.M. was provided by the Natural Sciences and Engineering Research Council of Canada (RGPIN 435380), Canada Foundation for Innovation (31271), Government of Alberta Research Capacity Program, and Canada Research Chairs program.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jmb.2015.12.01

    Mental Health Response in Haiti in the Aftermath of the 2010 Earthquake: A Case Study for Building Long-Term Solutions

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    Significant challenges exist in providing safe, effective, and culturally sound mental health and psychosocial services when an unforeseen disaster strikes in a low-resource setting. We present here a case study describing the experience of a transnational team in expanding mental health and psychosocial services delivered by two health care organizations, one local (Zanmi Lasante) and one international (Partners in Health), acting collaboratively as part of the emergency response to the 2010 Haiti earthquake. In the year and a half following the earthquake, Zanmi Lasante and Partners in Health provided 20,000 documented individual and group appointments for mental health and psychosocial needs. During the delivery of disaster response services, the collaboration led to the development of a model to guide the expansion and scaling up of community-based mental health services in the Zanmi Lasante health care system over the long-term, with potential for broader scale-up in Haiti. This model identifies key skill packages and implementation rules for developing evidence-based pathways and algorithms for treating common mental disorders. Throughout the collaboration, efforts were made to coordinate planning with multiple organizations interested in supporting the development of mental health programs following the disaster, including national governmental bodies, nongovernmental organizations, universities, foreign academic medical centers, and corporations. The collaborative interventions are framed here in terms of four overarching categories of action: direct service delivery, research, training, and advocacy. This case study exemplifies the role of psychiatrists working in low-resource settings as public health program implementers and as members of multidisciplinary teams. (Harv Rev Psychiatry 2012;20:68–77.

    Internal validation of STRmix™ – A multi laboratory response to PCAST

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    We report a large compilation of the internal validations of the probabilistic genotyping software STRmix™. Thirty one laboratories contributed data resulting in 2825 mixtures comprising three to six donors and a wide range of multiplex, equipment, mixture proportions and templates. Previously reported trends in the LR were confirmed including less discriminatory LRs occurring both for donors and non-donors at low template (for the donor in question) and at high contributor number. We were unable to isolate an effect of allelic sharing. Any apparent effect appears to be largely confounded with increased contributor number

    Altered RNA processing and export lead to retention of mRNAs near transcription sites and nuclear pore complexes or within the nucleolus.

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    Many protein factors are required for mRNA biogenesis and nuclear export, which are central to the eukaryotic gene expression program. It is unclear, however, whether all factors have been identified. Here we report on a screen of >1000 essential gene mutants in Saccharomyces cerevisiae for defects in mRNA processing and export, identifying 26 mutants with defects in this process. Single-molecule FISH data showed that the majority of these mutants accumulated mRNA within specific regions of the nucleus, which included 1) mRNAs within the nucleolus when nucleocytoplasmic transport, rRNA biogenesis, or RNA processing and surveillance was disrupted, 2) the buildup of mRNAs near transcription sites in 3'-end processing and chromosome segregation mutants, and 3) transcripts being enriched near nuclear pore complexes when components of the mRNA export machinery were mutated. These data show that alterations to various nuclear processes lead to the retention of mRNAs at discrete locations within the nucleus

    Charting Shifts in Saccharomyces cerevisiae Gene Expression across Asynchronous Time Trajectories with Diffusion Maps.

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    During fermentation, Saccharomyces cerevisiae metabolizes sugars and other nutrients to obtain energy for growth and survival, while also modulating these activities in response to cell-environment interactions. Here, differences in S. cerevisiae gene expression were explored over a time course of fermentation and used to differentiate fermentations, using Pinot noir grapes from 15 unique sites. Data analysis was complicated by the fact that the fermentations proceeded at different rates, making a direct comparison of time series gene expression data difficult with conventional differential expression tools. This led to the development of a novel approach combining diffusion mapping with continuous differential expression analysis (termed DMap-DE). Using this method, site-specific deviations in gene expression were identified, including changes in gene expression correlated with the non-Saccharomyces yeast Hanseniaspora uvarum, as well as initial nitrogen concentrations in grape musts. These results highlight novel relationships between site-specific variables and Saccharomyces cerevisiae gene expression that are linked to repeated fermentation outcomes. It was also demonstrated that DMap-DE can extract biologically relevant gene expression patterns from other contexts (e.g., hypoxic response of Saccharomyces cerevisiae) and offers advantages over other data dimensionality reduction approaches, indicating that DMap-DE offers a robust method for investigating asynchronous time series gene expression data. IMPORTANCE In this work, Saccharomyces cerevisiae gene expression was used as a biosensor to capture differences across and between fermentations of Pinot noir grapes from 15 unique sites representing eight American Viticultural Areas. This required development of a novel analysis method, DMap-DE, for investigation of asynchronous gene expression data. It was demonstrated that DMap-DE reveals biologically relevant shifts in gene expression related to cell-environment interactions in the context of hypoxia and fermentation. Using these data, it was discovered that gene expression by non-Saccharomyces yeasts and initial nitrogen content in grape musts are correlated with differences in gene expression among fermentations. These findings highlight important relationships between site-specific variables and gene expression that may be used to understand why foods and beverages, including wine, possess sensory characteristics associated with or derived from their place of origin

    Emerging molecular functions and novel roles for the DEAD-box protein Dbp5/DDX19 in gene expression

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    The DEAD-box protein (DBP) Dbp5, a member of the superfamily II (SFII) helicases, has multiple reported roles in gene expression. First identified as an essential regulator of mRNA export in Saccharomyces cerevisiae, the enzyme now has reported functions in non-coding RNA export, translation, transcription, and DNA metabolism. Localization of the protein to various cellular compartments (nucleoplasm, nuclear envelope, and cytoplasm) highlights the ability of Dbp5 to modulate different stages of the RNA lifecycle. While Dbp5 has been well studied for > 20 years, several critical questions remain regarding the mechanistic principles that govern Dbp5 localization, substrate selection, and functions in gene expression. This review aims to take a holistic view of the proposed functions of Dbp5 and evaluate models that accommodate current published data
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