biostudies-literatureUnknownBell CDuring cell division, chromosomes reorganise into compact bodies in which centromeres localise precisely at the chromatin surface to enable kinetochore-microtubule interactions essential for genome segregation. The physical principles guiding this centromere positioning remain unknown. Here, we reveal that human core centromeres are directed to the chromatin surface by repulsion of centromere-associated proteins - independent of condensin-mediated loop extrusion and microtubule engagement. Using cellular perturbations, biochemical reconstitution, and multiscale molecular dynamics simulations, we show that chromatin surface localisation emerges from repulsion between condensed chromatin and both the kinetochore and the highly negatively charged centromere protein, CENP-B. Together, these elbioRxiv : the preprint server for biology2025.09.01.673455https://www.ebi.ac.uk/biostudies/studies/S-EPMC12424837biostudies-literatureAn electrostatic repulsion model of centromere organisation.PMC12424837Huertas JBell CChen LSchuette NGerlich DWRosen MKLanger CCHRedding SEspinosa JRBlaukopf CSteinacker TLPerez Lopez JIZhou HDoolittle LMaristany MJCollepardo-Guevara RfalseAn electrostatic repulsion model of centromere organisation.During cell division, chromosomes reorganise into compact bodies in which centromeres localise precisely at the chromatin surface to enable kinetochore-microtubule interactions essential for genome segregation. The physical principles guiding this centromere positioning remain unknown. Here, we reveal that human core centromeres are directed to the chromatin surface by repulsion of centromere-associated proteins - independent of condensin-mediated loop extrusion and microtubule engagement. Using cellular perturbations, biochemical reconstitution, and multiscale molecular dynamics simulations, we show that chromatin surface localisation emerges from repulsion between condensed chromatin and both the kinetochore and the highly negatively charged centromere protein, CENP-B. Together, these el2025-01-01T00:00:00Z2025 Sep2026-04-27T03:12:22.195Z2026-04-27T03:10:26.676ZS-EPMC124248374095005610.1101/2025.09.01.673455