| 1. |
- Tedeschi, Antonio, et al.
(författare)
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Wapl is an essential regulator of chromatin structure and chromosome segregation
- 2013
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 501:7468, s. 564-568
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Tidskriftsartikel (refereegranskat)abstract
- Mammalian genomes contain several billion base pairs of DNA that are packaged in chromatin fibres. At selected gene loci, cohesin complexes have been proposed to arrange these fibres into higher-order structures, but how important this function is for determining overall chromosome architecture and how the process is regulated are not well understood. Using conditional mutagenesis in the mouse, here we show that depletion of the cohesin-associated protein Wapl stably locks cohesin on DNA, leads to clustering of cohesin in axial structures, and causes chromatin condensation in interphase chromosomes. These findings reveal that the stability of cohesin-DNA interactions is an important determinant of chromatin structure, and indicate that cohesin has an architectural role in interphase chromosome territories. Furthermore, we show that regulation of cohesin-DNA interactions by Wapl is important for embryonic development, expression of genes such as c-myc (also known as Myc), and cell cycle progression. In mitosis, Wapl-mediated release of cohesin from DNA is essential for proper chromosome segregation and protects cohesin from cleavage by the protease separase, thus enabling mitotic exit in the presence of functional cohesin complexes.
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| 2. |
- Wutz, Gordana, et al.
(författare)
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Topologically associating domains and chromatin loops depend on cohesin and are regulated by CTCF, WAPL, and PDS5 proteins
- 2017
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Ingår i: EMBO Journal. - : Springer Nature. - 0261-4189 .- 1460-2075. ; 36:24, s. 3573-3599
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Tidskriftsartikel (refereegranskat)abstract
- Mammalian genomes are spatially organized into compartments, topologically associating domains (TADs), and loops to facilitate gene regulation and other chromosomal functions. How compartments, TADs, and loops are generated is unknown. It has been proposed that cohesin forms TADs and loops by extruding chromatin loops until it encounters CTCF, but direct evidence for this hypothesis is missing. Here, we show that cohesin suppresses compartments but is required for TADs and loops, that CTCF defines their boundaries, and that the cohesin unloading factor WAPL and its PDS5 binding partners control the length of loops. In the absence of WAPL and PDS5 proteins, cohesin forms extended loops, presumably by passing CTCF sites, accumulates in axial chromosomal positions (vermicelli), and condenses chromosomes. Unexpectedly, PDS5 proteins are also required for boundary function. These results show that cohesin has an essential genome-wide function in mediating long-range chromatin interactions and support the hypothesis that cohesin creates these by loop extrusion, until it is delayed by CTCF in a manner dependent on PDS5 proteins, or until it is released from DNA by WAPL.
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| 3. |
- Beck, Martin, et al.
(författare)
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The quantitative proteome of a human cell line
- 2011
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Ingår i: Molecular Systems Biology. - : EMBO. - 1744-4292. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The generation of mathematical models of biological processes, the simulation of these processes under different conditions, and the comparison and integration of multiple data sets are explicit goals of systems biology that require the knowledge of the absolute quantity of the system's components. To date, systematic estimates of cellular protein concentrations have been exceptionally scarce. Here, we provide a quantitative description of the proteome of a commonly used human cell line in two functional states, interphase and mitosis. We show that these human cultured cells express at least similar to 10 000 proteins and that the quantified proteins span a concentration range of seven orders of magnitude up to 20 000 000 copies per cell. We discuss how protein abundance is linked to function and evolution. Molecular Systems Biology 7: 549; published online 8 November 2011; doi:10.1038/msb.2011.82
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| 4. |
- Lu, Wenshu, et al.
(författare)
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Sun1 forms immobile macromolecular assemblies at the nuclear envelope
- 2008
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Ingår i: Biochimica et Biophysica Acta. Molecular Cell Research. - : Elsevier BV. - 0167-4889 .- 1879-2596. ; 1783:12, s. 2415-2426
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Tidskriftsartikel (refereegranskat)abstract
- SUN-domain proteins form a novel and conserved family of inner nuclear membrane (INM) proteins, which establish physical connections between the nucleoplasm and the cytoskeleton. In the current study, we provide evidence that within the nuclear envelope (NE) Stint proteins form highly immobile oligomeric complexes in interphase cells. By performing inverse fluorescence recovery after photobleaching analysis, we demonstrate in vivo that both perinuclear and nucleoplasmic Sun I segments are essential for maintenance of Sun I immobility at the NE. Our data in Particular underline the self-association properties of the C-terminal coiled-coil Sun I segment, the ability of which to form dimers and tetramers is demonstrated. Furthermore, the Sun1 tertiary Structure involves interchain disulfide bonds that might contribute to higher homo-oligomer formation, although the overall dynamics of the Sun1 C-terminus remains unaffected when the cysteins involved are mutated. While a major Sun1 pool colocalizes with nuclear pore complex proteins, a large fraction of the Sun1 protein assemblies colocalize with immunoreactive foci of Sun2, another SUN-domain paralogue at the NE. We demonstrate that the Sun1 coiled-coil domain permits these heterophilic associations with Sun2. Sun1 therefore provides a non-dynamic platform for the formation of different macromolecular assemblies at the INM Our data support a model in which SUN-protein-containing multivariate complexes may provide versatile outer nuclear membrane attachment sites for cytoskeletal filaments. Crown
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| 5. |
- Uhlen, Mathias, et al.
(författare)
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A proposal for validation of antibodies
- 2016
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Ingår i: Nature Methods. - : Nature Publishing Group. - 1548-7091 .- 1548-7105. ; 13:10, s. 823-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We convened an ad hoc International Working Group for Antibody Validation in order to formulate the best approaches for validating antibodies used in common research applications and to provide guidelines that ensure antibody reproducibility. We recommend five conceptual 'pillars' for antibody validation to be used in an application-specific manner.
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| 6. |
- Wright, Graham D., et al.
(författare)
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Recognising the importance and impact of Imaging Scientists: Global guidelines for establishing career paths within core facilities
- 2024
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Ingår i: JOURNAL OF MICROSCOPY. - 0022-2720 .- 1365-2818. ; 294:3, s. 397-410
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Tidskriftsartikel (refereegranskat)abstract
- In the dynamic landscape of scientific research, imaging core facilities are vital hubs propelling collaboration and innovation at the technology development and dissemination frontier. Here, we present a collaborative effort led by Global BioImaging (GBI), introducing international recommendations geared towards elevating the careers of Imaging Scientists in core facilities. Despite the critical role of Imaging Scientists in modern research ecosystems, challenges persist in recognising their value, aligning performance metrics and providing avenues for career progression and job security. The challenges encompass a mismatch between classic academic career paths and service-oriented roles, resulting in a lack of understanding regarding the value and impact of Imaging Scientists and core facilities and how to evaluate them properly. They further include challenges around sustainability, dedicated training opportunities and the recruitment and retention of talent. Structured across these interrelated sections, the recommendations within this publication aim to propose globally applicable solutions to navigate these challenges. These recommendations apply equally to colleagues working in other core facilities and research institutions through which access to technologies is facilitated and supported. This publication emphasises the pivotal role of Imaging Scientists in advancing research programs and presents a blueprint for fostering their career progression within institutions all around the world. In the exciting world of scientific research, imaging core facilities are essential hubs where scientists use advanced technologies to conduct experiments and uncover fascinating discoveries. What makes these facilities remarkable is that multiple scientists can access and utilise a variety of instruments for a wide range of multidisciplinary research projects, fostering collaboration and innovation. At the forefront of this scientific adventure are Imaging Scientists, experts who play a crucial role in planning experiments, preparing materials, adapting and acquiring technologies, collecting data, training and supporting researchers, analysing images and forming conclusions. Despite their pivotal contributions, there are challenges in recognising the importance of Imaging Scientists and ensuring they have ample opportunities to advance in their careers. These challenges include a mismatch between the typical academic career path and the unique roles and responsibilities of Imaging Scientists, a lack of widespread understanding of their value plus financial constraints, insufficient training opportunities, and difficulties in attracting and retaining talented individuals. To address these issues, Global BioImaging (GBI; www.globalbioimaging.org) has brought together Imaging Scientists from around the world to develop a generally applicable set of recommendations in three key areas: highlighting the significance and value of Imaging Scientists, making it easier to recruit and retain them, and supporting their ongoing learning and professional growth. A notable concept is to reimagine the traditional separation between academic roles and technical support roles. GBI envisions that these recommendations will not only benefit imaging facilities but also prove valuable for research institutions housing diverse technologies organised into core facilities. Recognising the diverse nature of research performing institutions globally, the GBI community sees this guide as a starting point that will initiate dialogue and instigate change, which should be periodically updated as the needs of Imaging Scientists change. This initial version lays a solid foundation for future enhancements, contributing to the acknowledgement and support of the invaluable work done by Imaging Scientists on a global scale.
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