A new class of disordered elements controls DNA replication through initiator self-assembly

eLife

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[1] Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, United States;Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, United States;Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States;Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States;

关键词: DNA replication;    phase separation;    intrinsically disordered;    ORC;    Cdc6;    Cdt1;    D. melanogaster;   

DOI  :  10.7554/eLife.48562

来源: publisher

【 摘 要 】

10.7554/eLife.48562.001The initiation of DNA replication in metazoans occurs at thousands of chromosomal sites known as origins. At each origin, the Origin Recognition Complex (ORC), Cdc6, and Cdt1 co-assemble to load the Mcm2-7 replicative helicase onto chromatin. Current replication models envisage a linear arrangement of isolated origins functioning autonomously; the extent of inter-origin organization and communication is unknown. Here, we report that the replication initiation machinery of D. melanogaster unexpectedly undergoes liquid-liquid phase separation (LLPS) upon binding DNA in vitro. We find that ORC, Cdc6, and Cdt1 contain intrinsically disordered regions (IDRs) that drive LLPS and constitute a new class of phase separating elements. Initiator IDRs are shown to regulate multiple functions, including chromosome recruitment, initiator-specific co-assembly, and Mcm2-7 loading. These data help explain how CDK activity controls replication initiation and suggest that replication programs are subject to higher-order levels of inter-origin organization.

【 授权许可】

CC BY