article published yes Valerio Sorichetti author ef8a92cb-c7b6-11ec-8bea-e1fd5847bc5b0000-0002-9645-6576 Paul Robin author 48c58128-57b0-11ee-9095-dc28fd97fc1d0000-0002-5728-9189 Ivan Palaia author 9c805cd2-4b75-11ec-a374-db6dd0ed57fa 0000-0002-8843-9485 Alberto Hernandez-Armendariz author Sara Cuylen-Haering author Anđela Šarić author bf63d406-f056-11eb-b41d-f263a6566d8b0000-0002-7854-2139 AnSa department EdHa department Non-Equilibrium Protein Assembly: from Building Blocks to Biological Machines project IST-BRIDGE: International postdoctoral program project EMBO Young Investigator Program - Andela Saric project The condensation of charged polymers is an important driver for the formation of biomolecular condensates. Recent experiments suggest that this mechanism also controls the clustering of eukaryotic chromosomes during the late stages of cell division. In this process, interchromosome attraction is driven by the condensation of cytoplasmic RNA and Ki-67, a charged intrinsically disordered protein that coats the chromosomes as a brush. Attraction between chromosomes has been shown to be specifically promoted by a localized charged patch on Ki-67, although the physical mechanism remains unclear. To elucidate this process, we combine coarse-grained simulations and analytical theory to study the RNA-mediated interaction between charged polymer brushes on the chromosome surfaces. We show that the charged patch on Ki-67 leads to interchromosome attraction via RNA bridging between the two brushes, whereby the RNA preferentially interacts with the charged patches, leading to stable, long-range forces. By contrast, if the brush is uniformly charged, bridging is basically absent due to complete adsorption of RNA onto the brush. Moreover, the RNA dynamics becomes caged in presence of the charged patch while remaining diffusive with uniform charge. Our work sheds light on the physical origin of chromosome clustering, while also suggesting a general mechanism for cells to tune work production by biomolecular condensates via different charge distributions. https://research-explorer.ista.ac.at/download/21235/21287/2025_PRXLife_Sorichetti.pdf application/pdfno American Physical Society2025 eng 2835-827910.1103/41fd-r847 33 V. Sorichetti, P. Robin, I. Palaia, A. Hernandez-Armendariz, S. Cuylen-Haering, and A. Šarić, “Charge distribution of the coating brush drives interchromosome attraction,” <i>PRX Life</i>, vol. 3, no. 3. American Physical Society, 2025. Sorichetti, Valerio, Paul Robin, Ivan Palaia, Alberto Hernandez-Armendariz, Sara Cuylen-Haering, and Anđela Šarić. “Charge Distribution of the Coating Brush Drives Interchromosome Attraction.” <i>PRX Life</i>. American Physical Society, 2025. <a href="https://doi.org/10.1103/41fd-r847">https://doi.org/10.1103/41fd-r847</a>. Sorichetti, V., Robin, P., Palaia, I., Hernandez-Armendariz, A., Cuylen-Haering, S., &#38; Šarić, A. (2025). Charge distribution of the coating brush drives interchromosome attraction. <i>PRX Life</i>. American Physical Society. <a href="https://doi.org/10.1103/41fd-r847">https://doi.org/10.1103/41fd-r847</a> V. Sorichetti, P. Robin, I. Palaia, A. Hernandez-Armendariz, S. Cuylen-Haering, A. Šarić, PRX Life 3 (2025). Sorichetti V, Robin P, Palaia I, Hernandez-Armendariz A, Cuylen-Haering S, Šarić A. 2025. Charge distribution of the coating brush drives interchromosome attraction. PRX Life. 3(3), 033010. Sorichetti V, Robin P, Palaia I, Hernandez-Armendariz A, Cuylen-Haering S, Šarić A. Charge distribution of the coating brush drives interchromosome attraction. <i>PRX Life</i>. 2025;3(3). doi:<a href="https://doi.org/10.1103/41fd-r847">10.1103/41fd-r847</a> Sorichetti, Valerio, et al. “Charge Distribution of the Coating Brush Drives Interchromosome Attraction.” <i>PRX Life</i>, vol. 3, no. 3, 033010, American Physical Society, 2025, doi:<a href="https://doi.org/10.1103/41fd-r847">10.1103/41fd-r847</a>. 212352026-02-16T14:50:32Z2026-02-17T11:16:26Z