143 research outputs found

    The Chromosomal Passenger Complex Activates Polo Kinase at Centromeres

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    The coordinated activities at centromeres of two key cell cycle kinases, Polo and Aurora B, are critical for ensuring that the two sister kinetochores of each chromosome are attached to microtubules from opposite spindle poles prior to chromosome segregation at anaphase. Initial attachments of chromosomes to the spindle involve random interactions between kinetochores and dynamic microtubules, and errors occur frequently during early stages of the process. The balance between microtubule binding and error correction (e.g., release of bound microtubules) requires the activities of Polo and Aurora B kinases, with Polo promoting stable attachments and Aurora B promoting detachment. Our study concerns the coordination of the activities of these two kinases in vivo. We show that INCENP, a key scaffolding subunit of the chromosomal passenger complex (CPC), which consists of Aurora B kinase, INCENP, Survivin, and Borealin/Dasra B, also interacts with Polo kinase in Drosophila cells. It was known that Aurora A/Bora activates Polo at centrosomes during late G2. However, the kinase that activates Polo on chromosomes for its critical functions at kinetochores was not known. We show here that Aurora B kinase phosphorylates Polo on its activation loop at the centromere in early mitosis. This phosphorylation requires both INCENP and Aurora B activity (but not Aurora A activity) and is critical for Polo function at kinetochores. Our results demonstrate clearly that Polo kinase is regulated differently at centrosomes and centromeres and suggest that INCENP acts as a platform for kinase crosstalk at the centromere. This crosstalk may enable Polo and Aurora B to achieve a balance wherein microtubule mis-attachments are corrected, but proper attachments are stabilized allowing proper chromosome segregation

    Parallel Chemical Genetic and Genome-Wide RNAi Screens Identify Cytokinesis Inhibitors and Targets

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    Cytokinesis involves temporally and spatially coordinated action of the cell cycle and cytoskeletal and membrane systems to achieve separation of daughter cells. To dissect cytokinesis mechanisms it would be useful to have a complete catalog of the proteins involved, and small molecule tools for specifically inhibiting them with tight temporal control. Finding active small molecules by cell-based screening entails the difficult step of identifying their targets. We performed parallel chemical genetic and genome-wide RNA interference screens in Drosophila cells, identifying 50 small molecule inhibitors of cytokinesis and 214 genes important for cytokinesis, including a new protein in the Aurora B pathway (Borr). By comparing small molecule and RNAi phenotypes, we identified a small molecule that inhibits the Aurora B kinase pathway. Our protein list provides a starting point for systematic dissection of cytokinesis, a direction that will be greatly facilitated by also having diverse small molecule inhibitors, which we have identified. Dissection of the Aurora B pathway, where we found a new gene and a specific small molecule inhibitor, should benefit particularly. Our study shows that parallel RNA interference and small molecule screening is a generally useful approach to identifying active small molecules and their target pathways

    Towards a cancer mission in Horizon Europe: recommendations.

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    A comprehensive translational cancer research approach focused on personalized and precision medicine, and covering the entire cancer research-care-prevention continuum has the potential to achieve in 2030 a 10-year cancer-specific survival for 75% of patients diagnosed in European Union (EU) member states with a well-developed healthcare system. Concerted actions across this continuum that spans from basic and preclinical research through clinical and prevention research to outcomes research, along with the establishment of interconnected high-quality infrastructures for translational research, clinical and prevention trials and outcomes research, will ensure that science-driven and social innovations benefit patients and individuals at risk across the EU. European infrastructures involving comprehensive cancer centres (CCCs) and CCC-like entities will provide researchers with access to the required critical mass of patients, biological materials and technological resources and can bridge research with healthcare systems. Here, we prioritize research areas to ensure a balanced research portfolio and provide recommendations for achieving key targets. Meeting these targets will require harmonization of EU and national priorities and policies, improved research coordination at the national, regional and EU level and increasingly efficient and flexible funding mechanisms. Long-term support by the EU and commitment of Member States to specialized schemes are also needed for the establishment and sustainability of trans-border infrastructures and networks. In addition to effectively engaging policymakers, all relevant stakeholders within the entire continuum should consensually inform policy through evidence-based advice

    German S3 guideline "actinic keratosis and cutaneous squamous cell carcinoma" – long version of the update 2023

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    Actinic keratosis (AK) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guideline “actinic keratosis and cutaneous squamous cell carcinoma” was updated and expanded by the topics cutanepus squamous cell carcinoma in situ (Bowen’s disease) and actinic cheilitis. This guideline was developed at the highest evidence level (S3) and is aimed at dermatologists, general practitioners, ear nose and throat specialists, surgeons, oncologists, radiologists and radiation oncologists in hospitals and office-based settings, as well as other medical specialties, policy makers and insurance funds involved in the diagnosis and treatment of patients with AK and cSCC

    Europa im Geflecht der Welt

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    Der Band dokumentiert Vorträge und Workshops der internationalen Abschlusstagung des DFG-Schwerpunktprogrammes 1173 „Integration und Desintegration der Kulturen im europäischen Mittelalter“, die Ende Mai 2011 in Berlin stattgefunden hat. Bei der Arbeit im Schwerpunktprogramm hatte sich gezeigt, wie schwierig es ist, Europa im geographischen und historischen Sinne vom Mittelmeerraum mit Nordafrika und Vorder¬asien zu trennen. Daher wurden die Grenzen des mittelalterlichen Europa bewusst überschritten und auch die Geschichte weiter entfernter Länder in den Blick genommen. Als thematischer Schwerpunkt boten sich in diesem Zusammenhang Migrationen an. Migrationen sind ja ein globales Phäno¬men, das an allen Orten und zu allen Zeiten immer wieder die Geschichte der Menschheit prägt und dabei unvermeidlich – selbst in der scheinbaren Isolation einer „Diaspora“ oder „Parallelgesellschaft“ – zu transkulturellen Verflechtungen führt. Fremde und einheimische Gruppen und Individuen werden in neue soziale Umgebungen gerückt und Kontakte oder Konflikte zwischen ihnen erzeugt. Wo aber das jeweilige Leben gegeneinander abgeschottet werden soll, verliert Kultur ihre Inno¬vations¬kraft und versteinert die Gesellschaft. Mit dem Sachthema der „Migrationen“ und mit einem Blick weit über Europa hinaus, bis nach Amerika, Japan und ins südliche Afrika, wird der Übergang von einer eurozentrierten Mittelalterforschung zu einer transdisziplinären Mediävistik in globalen Zusammenhängen markiert
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