Limits of Chromosome Compaction by Loop-Extruding Motors
Name
PhysRevX.9.031007.pdf
Description
Published version
Size
590.49 KB
Format
Adobe PDF
Checksum (MD5)
909890a359d6e0f6083053787ad38760
Author(s)
Banigan, Edward J
Mirny, Leonid A
Date Issued
July 2019
Journal
Physical Review X
Publisher
American Physical Society (APS)
Citation
Banigan, Edward J. and Leonid A. Mirny. "Limits of Chromosome Compaction by Loop-Extruding Motors." Physical Review X 9, 3 (July 2019): 031007
Version
Final published version
Abstract
During mitosis, human chromosomes are linearly compacted about 1000-fold by loop-extruding motors. Recent experiments have shown that condensins extrude DNA loops but in a “one-sided” manner. This contrasts with existing models, which predict that symmetric, “two-sided” loop extrusion accounts for mitotic chromosome compaction. We explore whether one-sided extrusion, as it is currently seen in experiments, can compact chromosomes by developing a mean-field theoretical model for polymer compaction by motors that actively extrude loops and dynamically turnover. The model establishes a stringent upper bound of only about tenfold for compaction by strictly one-sided extrusion. We confirm this result with stochastic simulations. Thus, strictly one-sided extrusion as it has been observed so far cannot be the sole mechanism of chromosome compaction. However, as shown by the model, other two-sided or effectively two-sided mechanisms can achieve sufficient compaction.
MIT Department
Massachusetts Institute of Technology. Institute for Medical Engineering & Science
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1103/physrevx.9.031007
