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Title: Temporally Correlated Active Forces Drive Segregation and Enhanced Dynamics in Chromosome Polymers
Understanding the mechanisms governing the structure and dynamics of flexible polymers like chromosomes, especially the signatures of motor-driven active processes, is of great interest in genome biology. We study chromosomes as a coarse-grained polymer model where microscopic motor activity is captured via an additive temporally persistent noise. The active steady state is characterized by two parameters: active force, controlling the persistent-noise amplitude, and correlation time, the decay time of active noise. We find that activity drives correlated motion over long distances and a regime of dynamic compaction into a globally collapsed entangled globule. Diminished topological constraints destabilize the entangled globule, and the active segments trapped in the globule move toward the periphery, resulting in an enriched active monomer density near the periphery. We also show that heterogeneous activity leads to the segregation of the highly dynamic species from the less dynamic one, suggesting a role of activity in chromosome compartmental segregation. Adding activity to experimental-data-derived structures, we find active loci may mechanically perturb and switch compartments established via epigenetics-driven passive self-association. The key distinguishing signatures of activity are enhanced apparent diffusivity, exploration of all the dynamic regimes (subdiffusion, effective diffusion, and superdiffusion) at various lag times, and a broadened distribution of observables like the dynamic exponents. Published by the American Physical Society2024  more » « less
Award ID(s):
2224030 2019745 2210291
PAR ID:
10536956
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Physical Review
Date Published:
Journal Name:
PRX Life
Volume:
2
Issue:
3
ISSN:
2835-8279
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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