38 research outputs found
Cdk1 and Plk1 mediate a CLASP2 Phospho-Switch that Stabilizes KinetochoreâMicrotubule Attachments
Accurate chromosome segregation during mitosis relies on a dynamic kinetochore (KT)-microtubule (MT) interface that switches from a labile to a stable condition in response to correct MT attachments. This transition is essential to satisfy the spindle-assembly checkpoint (SAC) and couple MT-generated force with chromosome movements, but the underlying regulatory mechanism remains unclear. In this study, we show that during mitosis the MT- and KT-associated protein CLASP2 is progressively and distinctively phosphorylated by Cdk1 and Plk1 kinases, concomitant with the establishment of KT-MT attachments. CLASP2 S1234 was phosphorylated by Cdk1, which primed CLASP2 for association with Plk1. Plk1 recruitment to KTs was enhanced by CLASP2 phosphorylation on S1234. This was specifically required to stabilize KT-MT attachments important for chromosome alignment and to coordinate KT and non-KT MT dynamics necessary to maintain spindle bipolarity. CLASP2 C-terminal phosphorylation by Plk1 was also required for chromosome alignment and timely satisfaction of the SAC. We propose that Cdk1 and Plk1 mediate a fine CLASP2 phospho-switch that temporally regulates KT-MT attachment stability
Human Resource Management in the Countries of the Former Yugoslavia
Human Resource Management (HR/HRM) is closely connected to the social and economic environment in which a given organization or company operates. On this basis it may be interesting for foreign potential investors to understand both the differences and similarities in the application of HRM methods in a group of countries which had lived for a long period of time in a federation which had finally disintegrated. Such investors usually come from different environments and backgrounds and have previous experience in the application of specific forms of HRM practice. In this paper the authors try to present the development and changes in the theories and practice of Human Resource Management in most of the countries established on the territory of the former Socialist Federal Republic of Yugoslavia: Bosnia and Herzegovina, Croatia, Macedonia, Serbia and Slovenia.human resource management; economic environment; practices change; former Yugoslavia.
A NEW CASE OF INTRAGENIC DELETION OF THE TCF4 GENE WITHOUT FEATURES OF PITT-HOPKINS SYNDROME
Different genomic alterations affecting the TCF4 gene are usually associated with Pitt-Hopkins syndrome (PTHS). This syndrome is a rare neurodevelopmental genetic disorder characterized by distinctive facial features, abnormal breathing, psychomotor delay and severe intellectual disability (ID). The genomic alterations include whole or partial gene deletion; balanced translocation disrupting the coding sequence of the gene; and intragenic variants. The TCF4 gene encodes a basic helix-loop-helix (bHLH) transcription factor 4. Using alternative promoters, TCF4 can be transcribed from a number of alternative initial exons, allowing for translation of variable protein isoforms containing different functional domains. Full-length TCF4 has two activation domains (AD1 and AD2) that are thought to modulate transcriptional activity, a NLS domain (nuclear localization signal) that controls subcellular localization and bHLH domain. Typical PTHS patients have aberration localized between exons 9 and 18 of the gene. On the other hand, variants affecting the first protein coding exons give rise to mild non-syndromic ID. We present a ten-year-old girl with psychomotor delay and mild ID without the typical features of PTHS. Genetic investigation using array-based comparative genomic hybridization, revealed a 73.45 kb deletion within the TCF4 gene. The deletion encompassing only exon 6 (NM_001083962). This deletion was not detected in both parents. Cytogenetic analysis excluded balanced translocation disrupting the coding sequence of the gene. To the best of our knowledge, this is the first case described in literature involving only exon 6. The findings in our patients support the notion that position of the alteration in TCF4 is relevant to the phenotype. Reporting our case we want to contribute to the phenotype-genotype correlation in patients with intragenomic deletion of TCF4 gene
Transmission and survival of carbapenem-resistant Acinetobacter baumannii outside hospital setting
Acinetobacter baumannii origin and its epidemiology is under a great concern worldwide since this microorganism has become a leading nosocomial pathogen of the 21th century among the "ESKAPE" group of microorganisms. The aim of the study was to monitor and explore the epidemiology of this important hospital pathogen in the second largest clinical university hospital in Croatia. The presence of A. baumannii in hospital wastewater, as a route for possible transmission outside of the hospital setting, as well as its survival in environmental conditions including seawater, was investigated. During the examination period, ten both carbapenem and multidrug-resistant isolates of A. baumannii were recovered from hospital wastewater and compared to the clinical isolates originating from the same monitoring period. Multiplex PCR confirmed that four wastewater isolates harboured blaOXA-23-like, while five wastewater isolates harboured blaOXA-40-like genes sharing 100% sequence identity with blaOXA-72 sequence described in the same hospital in 2009, confirming the presence of an endemic cluster. Survival of A. baumannii in natural seawater was examined during 50 days of monitoring and to the best of our knowledge, was performed for the first time.Keywords: Acinetobacter baumannii · hospital wastewater · transmission · seawate
Cdk1 and Plk1 mediate a CLASP2 phospho-switch that stabilizes kinetochoreâmicrotubule attachments
Accurate chromosome segregation during mitosis relies on a dynamic kinetochore (KT)âmicrotubule (MT) interface that switches from a labile to a stable condition in response to correct MT attachments. This transition is essential to satisfy the spindle-assembly checkpoint (SAC) and couple MT-generated force with chromosome movements, but the underlying regulatory mechanism remains unclear. In this study, we show that during mitosis the MT- and KT-associated protein CLASP2 is progressively and distinctively phosphorylated by Cdk1 and Plk1 kinases, concomitant with the establishment of KTâMT attachments. CLASP2 S1234 was phosphorylated by Cdk1, which primed CLASP2 for association with Plk1. Plk1 recruitment to KTs was enhanced by CLASP2 phosphorylation on S1234. This was specifically required to stabilize KTâMT attachments important for chromosome alignment and to coordinate KT and non-KT MT dynamics necessary to maintain spindle bipolarity. CLASP2 C-terminal phosphorylation by Plk1 was also required for chromosome alignment and timely satisfaction of the SAC. We propose that Cdk1 and Plk1 mediate a fine CLASP2 âphospho-switchâ that temporally regulates KTâMT attachment stability.National Institutes of Health (U.S.) (NIH/National Institute of General Medical Sciences grant GM088313)National Institutes of Health (U.S.) (NIH grant 5R01-GM078373)American Heart Association (grant-in-aid 10GRNT4230026)National Institutes of Health (U.S.) (NIH grant GM51542)FundaçaÌo para a CieÌncia e a Tecnologia (FCT grant REEQ/564/BIO/2005 (EU-FEDER), POCI 2010
COVID-19 and children with congenital anomalies:a European survey of parents' experiences of healthcare services
Objective: To survey parents and carers of children with a congenital anomaly across Europe about their experiences of healthcare services and support during the COVID-19 pandemic. Design: Cross-sectional study. Setting: Online survey in 10 European countries, open from 8 March 2021 to 14 July 2021. Population: 1070 parents and carers of children aged 0-10 years with a cleft lip, spina bifida, congenital heart defect (CHD) requiring surgery and/or Down syndrome. Main outcome measures: Parental views about: the provision of care for their child (cancellation/postponement of appointments, virtual appointments, access to medication), the impact of disruptions to healthcare on their child's health and well-being, and satisfaction with support from medical sources, organisations and close relationships. Results: Disruptions to healthcare appointments were significantly higher (p<0.001) in the UK and Poland, with approximately two-thirds of participants reporting ù ⏠cancelled or postponed' tests (67/101; 256/389) and procedures compared with approximately 20% in Germany (13/74) and Belgium/Netherlands (11/55). A third of participants in the UK and Poland reported ù ⏠cancelled or postponed' surgeries (22/72; 98/266) compared with only 8% in Germany (5/64). In Poland, 43% (136/314) of parents reported that changes to their child's ongoing treatment had moderately to severely affected their child's health, significantly higher than all other countries (p<0.001). Satisfaction ratings for support from general practitioners were lowest in the UK and Poland, and lowest in Poland and Italy for specialist doctors and nurses. Conclusion: A large proportion of participants reported disruptions to healthcare during the pandemic, which for some had a significant impact on their child's health. Regional differences in disruptions raise questions about the competence of certain healthcare systems to meet the needs of this vulnerable group of patients and indicate improvements should be strived for in some regions
Molecular mechanism of dynein recruitment to kinetochores by the Rod-Zw10-Zwilch complex and Spindly
The molecular motor dynein concentrates at the kinetochore region of mitotic chromosomes in animals to accelerate spindle microtubule capture and to control spindle checkpoint signaling. In this study, we describe the molecular mechanism used by the Rod-Zw10-Zwilch complex and the adaptor Spindly to recruit dynein to kinetochores in Caenorhabditis elegans embryos and human cells. We show that Rod's N-terminal beta-propeller and the associated Zwilch subunit bind Spindly's C-terminal domain, and we identify a specific Zwilch mutant that abrogates Spindly and dynein recruitment in vivo and Spindly binding to a Rod beta-propeller-Zwilch complex in vitro. Spindly's N-terminal coiled-coil uses distinct motifs to bind dynein light intermediate chain and the pointed-end complex of dynactin. Mutations in these motifs inhibit assembly of a dynein-dynactin-Spindly complex, and a null mutant of the dynactin pointed-end subunit p27 prevents kinetochore recruitment of dynein-dynactin without affecting other mitotic functions of the motor. Conservation of Spindly-like motifs in adaptors involved in intracellular transport suggests a common mechanism for linking dynein to cargo.This work was supported by a European Research Council Starting Grant (Dyneinome 338410) and a European Molecular Biology Organization Installation Grant to R. Gassmann. This work was also supported by funding from the Fundacao para a Ciencia e a Tecnologia to R. Gassmann (IF/01015/2013/CP1157/CT0006), C. Pereira (SFRH_BPD_95648_2013), and D.J. Barbosa (SFRH_BPD_101898_2014). Some C. elegans strains were provided by the Caenorhabditis Genetics Center, which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40 OD010440)
Uncovering the Molecular Machinery of the Human SpindleâAn Integration of Wet and Dry Systems Biology
The mitotic spindle is an essential molecular machine involved in cell division, whose composition has been studied extensively by detailed cellular biology, high-throughput proteomics, and RNA interference experiments. However, because of its dynamic organization and complex regulation it is difficult to obtain a complete description of its molecular composition. We have implemented an integrated computational approach to characterize novel human spindle components and have analysed in detail the individual candidates predicted to be spindle proteins, as well as the network of predicted relations connecting known and putative spindle proteins. The subsequent experimental validation of a number of predicted novel proteins confirmed not only their association with the spindle apparatus but also their role in mitosis. We found that 75% of our tested proteins are localizing to the spindle apparatus compared to a success rate of 35% when expert knowledge alone was used. We compare our results to the previously published MitoCheck study and see that our approach does validate some findings by this consortium. Further, we predict so-called âhidden spindle hubâ, proteins whose network of interactions is still poorly characterised by experimental means and which are thought to influence the functionality of the mitotic spindle on a large scale. Our analyses suggest that we are still far from knowing the complete repertoire of functionally important components of the human spindle network. Combining integrated bio-computational approaches and single gene experimental follow-ups could be key to exploring the still hidden regions of the human spindle system
Pressure-induced tuning of phase transition and role of disorder in electrical transport properties of beta-Sr_xV_6O_15
Thermoelectric power in Bi2Sr2Ca1-xPrxCu2O8+delta in a wide temperature range
Scientific conference paper We report thermopower and electrical resistance measurements of the high-temperature superconductor Bi2Sr2Ca1-xPrxCu2O8+delta (0 < x < 1) in a wide temperature range from 600 K to superconducting transition temperature (critical temperature, T-c). The transition temperature decreases with increasing x. Resistance obeys usual metallic linearity at higher temperatures, whereas at lower temperatures, before T-c (T similar to 300 K), a deviation from the linear trend is observed. Thermopower exhibits apparently non-metallic behavior - it increases with decreasing temperature and develops a broad maximum whose position and width increase with x. The results are discussed in the framework of several models present in the literature