A5085903358- Microtubule and mitosis dynamics
- Photosynthetic Processes and Mechanisms
- Cellular Mechanics and Interactions
- Genomics and Chromatin Dynamics
- Protist diversity and phylogeny
- Cellular transport and secretion
- Plant Molecular Biology Research
- Fungal and yeast genetics research
- Advanced Fluorescence Microscopy Techniques
- DNA Repair Mechanisms
- Chromosomal and Genetic Variations
- Nuclear Structure and Function
- Plant nutrient uptake and metabolism
- Microfluidic and Bio-sensing Technologies
- Orbital Angular Momentum in Optics
- Micro and Nano Robotics
- thermodynamics and calorimetric analyses
- Spaceflight effects on biology
- 3D Printing in Biomedical Research
- Biocrusts and Microbial Ecology
- Graph theory and applications
- Ubiquitin and proteasome pathways
- Computational Drug Discovery Methods
- Advanced Electron Microscopy Techniques and Applications
- Mitochondrial Function and Pathology
Rudjer Boskovic Institute
2015-2024
Max Planck Institute of Molecular Cell Biology and Genetics
2013-2023
Centre for Genomic Regulation
2022
University of Edinburgh
2021
Max Planck Society
2006-2014
University of Florence
2006
Max Planck Institut für Zellbiologie
2006
European Laboratory for Non-Linear Spectroscopy
2005
Harvard University
2000-2004
Harvard University Press
2001-2002
Adherent cells exert tractions on their surroundings. These can be measured by observing the displacements of beads embedded a flexible gel substrate which are cultured. This paper presents an exact solution to problem computing traction field from observed displacement field. The rests recasting relationship between and into Fourier space, where recovery is especially simple. We present two subcases solution, depending whether or not outside cell boundaries set zero. implementation...
Alternative models of cell mechanics depict the living as a simple mechanical continuum, porous filament gel, tensed cortical membrane, or tensegrity network that maintains stabilizing prestress through incorporation discrete structural elements bear compression. Real-time microscopic analysis cells containing GFP-labeled microtubules and associated mitochondria revealed behave like structures composed an interconnected actin microfilaments when stresses are applied to surface integrin...
The tensegrity hypothesis holds that the cytoskeleton is a structure whose shape stabilized predominantly by tensile stresses borne filamentous structures. Accordingly, cell stiffness must increase in proportion with level of stress, which called prestress. Here we have tested prediction adherent human airway smooth muscle (HASM) cells. Traction microscopy was used to measure distribution contractile arising at interface between each and its substrate; this traction field. Because field be...
The viscoelastic properties of the cytoplasm living yeast cells were investigated by studying motion lipid granules naturally occurring in cytoplasm. A large frequency range observation was obtained a combination video-based and laser-based tracking methods. At time scales from ${10}^{\ensuremath{-}4}$ to ${10}^{2}\text{ }\mathrm{s}$, typically perform subdiffusive with characteristics different previous measurements cells. This behavior is thought be due presence polymer networks membranous...
Microtubules are polymeric protein structures and components of the cytoskeleton. Their dynamic polymerization is important for diverse cellular functions. The centrosome classical site microtubule nucleation thought to be essential axon growth neuronal differentiation--processes that require assembly. We found loses its function as a organizing center during development rodent hippocampal neurons. Axons still extended regenerated through acentrosomal nucleation, axons continued grow after...
Chromosome segregation errors during cell divisions generate aneuploidies and micronuclei, which can undergo extensive chromosomal rearrangements such as chromothripsis1-5. Selective pressures then shape distinct aneuploidy rearrangement patterns-for example, in cancer6,7-but it is unknown whether initial biases micronucleation exist for particular chromosomes. Using single-cell DNA sequencing8 after an error-prone mitosis untransformed, diploid lines organoids, we show that chromosomes have...
Centromeres are scaffolds for the assembly of kinetochores that ensure chromosome segregation during cell division. How vertebrate centromeres obtain a three-dimensional structure to accomplish their primary function is unclear. Using super-resolution imaging, capture-C, and polymer modeling, we show partitioned by condensins into two subdomains mitosis. The bipartite found in human, mouse, chicken cells therefore fundamental feature centromeres. Super-resolution imaging electron tomography...
The tensegrity model hypothesizes that cytoskeleton-based microtubules (MTs) carry compression as they balance a portion of cell contractile stress. To test this hypothesis, we used traction force microscopy to measure at the interface adhering human airway smooth muscle cells and flexible polyacrylamide gel substrate. prediction is if MTs stress, then, upon their disruption, stress balanced by would shift substrate, thereby causing an increase in traction. Measurements were done first...
Abstract During metaphase, forces on kinetochores are exerted by k-fibres, bundles of microtubules that end at the kinetochore. Interestingly, non-kinetochore have been observed between sister kinetochores, but their function is unknown. Here we show laser-cutting a k-fibre in HeLa and PtK1 cells bundle microtubules, which term ‘bridging fibre’, bridges k-fibres balances interkinetochore tension. We found PRC1 EB3 bridging fibre, suggesting it consists antiparallel dynamic microtubules. By...
During cell division, mitotic spindle microtubules segregate chromosomes by exerting forces on kinetochores. What drive chromosome segregation in anaphase remains a central question. The current model for human cells includes shortening of kinetochore fibers and separation poles. Both processes require kinetochores to be linked with the Here we show, combining laser ablation, photoactivation, theoretical modeling, that can separate without any attachment one pole. This requires bridging...
Scientific Report27 December 2016Open Access Source DataTransparent process PRC1-labeled microtubule bundles and kinetochore pairs show one-to-one association in metaphase Bruno Polak Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia Search for more papers by this author Patrik Risteski Sonja Lesjak Iva M Tolić Corresponding Author [email protected] orcid.org/0000-0003-1305-7922 Information Polak1,‡, Risteski1,‡, Lesjak1 *,1 1Division ‡These authors contributed equally...
Proper chromosome segregation into two future daughter cells requires the mitotic spindle to elongate in anaphase. However, although some candidate proteins are implicated this process, molecular mechanism that drives elongation human is unknown. Using combined depletion and inactivation assays together with CRISPR technology explore redundancy between multiple targets, we discovered force-generating of consists EG5/kinesin-5 PRC1-dependent motor KIF4A/kinesin-4, contribution from kinesin-6...
During metaphase, chromosome position at the spindle equator is regulated by forces exerted kinetochore microtubules and polar ejection forces. However, role of arising from mechanical coupling sister fibers with bridging in alignment unknown. Here, we develop an optogenetic approach for acute removal PRC1 to partially disassemble show that they promote alignment. Tracking plus-end protein EB3 revealed longer antiparallel overlaps upon removal, which was accompanied misaligned lagging...
Eukaryotes have evolved towards one of two extremes along a spectrum strategies for remodelling the nuclear envelope during cell division: disassembling in an open mitosis or constructing intranuclear spindle closed
Tractions that cells exert on their substrates are essential in cell spreading, migration, and contraction. These tractions can be determined by plating the a flexible gel measuring deformation of using fluorescent beads embedded just below surface gel. In this article we describe image correlation method (ICM) optimized for determining displacement field under contracting cell. For calculation traction from use recently developed Fourier transform cytometry (FTTC). The ICM FTTC methods...
Meiotic nuclear oscillations in the fission yeast Schizosaccharomyces pombe are crucial for proper chromosome pairing and recombination. We report a mechanism of these on basis collective behavior dynein motors linking cell cortex dynamic microtubules that extend from spindle pole body opposite directions. By combining quantitative live imaging laser ablation with theoretical description, we show dynamically redistributes response to load forces, resulting more attached leading than trailing...
Abstract Mitosis relies on forces generated in the spindle, a micro-machine composed of microtubules and associated proteins. Forces are required for congression chromosomes to metaphase plate their separation anaphase. However, besides forces, torques may exist yet they have not been investigated. Here we show that spindle is chiral. Chirality evident from finding microtubule bundles human spindles follow left-handed helical path, which cannot be explained by but rather torques. Kinesin-5...