CRY Drives Cyclic CK2-Mediated BMAL1 Phosphorylation to Control the Mammalian Circadian Clock

PLoS Biol. 2015 Nov 12;13(11):e1002293. doi: 10.1371/journal.pbio.1002293. eCollection 2015.


Intracellular circadian clocks, composed of clock genes that act in transcription-translation feedback loops, drive global rhythmic expression of the mammalian transcriptome and allow an organism to anticipate to the momentum of the day. Using a novel clock-perturbing peptide, we established a pivotal role for casein kinase (CK)-2-mediated circadian BMAL1-Ser90 phosphorylation (BMAL1-P) in regulating central and peripheral core clocks. Subsequent analysis of the underlying mechanism showed a novel role of CRY as a repressor for protein kinase. Co-immunoprecipitation experiments and real-time monitoring of protein-protein interactions revealed that CRY-mediated periodic binding of CK2β to BMAL1 inhibits BMAL1-Ser90 phosphorylation by CK2α. The FAD binding domain of CRY1, two C-terminal BMAL1 domains, and particularly BMAL1-Lys537 acetylation/deacetylation by CLOCK/SIRT1, were shown to be critical for CRY-mediated BMAL1-CK2β binding. Reciprocally, BMAL1-Ser90 phosphorylation is prerequisite for BMAL1-Lys537 acetylation. We propose a dual negative-feedback model in which a CRY-dependent CK2-driven posttranslational BMAL1-P-BMAL1 loop is an integral part of the core clock oscillator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ARNTL Transcription Factors / chemistry
  • ARNTL Transcription Factors / genetics
  • ARNTL Transcription Factors / metabolism*
  • Animals
  • Casein Kinase II / chemistry
  • Casein Kinase II / genetics
  • Casein Kinase II / metabolism*
  • Cell Line
  • Cells, Cultured
  • Circadian Clocks*
  • Cryptochromes / chemistry
  • Cryptochromes / genetics
  • Cryptochromes / metabolism*
  • Embryo, Mammalian / cytology
  • Humans
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Mutation
  • Phosphorylation
  • Protein Interaction Domains and Motifs
  • Protein Processing, Post-Translational*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism


  • ARNTL Transcription Factors
  • Arntl protein, mouse
  • Cry1 protein, mouse
  • Cry2 protein, mouse
  • Cryptochromes
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • CSNK2A1 protein, human
  • Casein Kinase II

Grant support

This study was supported by the Japanese MEXT (Ministry of Education, Culture, Sports, Science and Technology; for TT (KAKENHI; 23590283, 15K08217) and TO (KAKENHI; 26220805) and the Takeda Science Foundation ( for TT. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.