Theory of chromosome structural dynamics by processive loop extrusion

• 成果类型: Article
• 署名作者: Cao, Zhiyu; Du, Chaoqun; Hou, Zhonghuai; Wolynes, Peter G.
• 署名单位: Rice University; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Rice University; Rice University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2609796123
• 发表日期: 2026-06-02
• 页码: e2609796123
• 关键词: active matter; loop extrusion; motor proteins; polymer physics; dna; ORGANIZATION; compaction

摘要

The processivity of Structural Maintenance of Chromosome complexes defines the characteristic run length and lifetime of loop extrusion events, which set up the large-scale architecture of chromosomes. We introduce an active, non-Markovian mechanistic model that explicitly incorporates motor processivity to provide a statistical mechanical treatment that identifies the nontrivial effects induced by the processive character of such active motors. At low activity, in interphase, processive loop extrusion generates effective cooperative multibody interactions, which lead to the so-called chromatin jets. Upon increasing activity, symmetry breaking occurs, as seen in the characteristic, cylindrically anisotropic mitotic chromosome organization. The strength of the motor processivity determines whether the symmetry breaking transition leads to crystalline ordering or to liquid-crystalline architectures for the mitotic chromosome.