TRITHORAX-dependent arginine methylation of HSP68 mediates circadian repression by PERIOD in the monarch butterfly Academic Article uri icon


  • Significance Circadian repression drives the transcriptional feedback loops that keep circadian (∼24-h) time and synchronize an animal’s physiology and behavior to the daily environmental changes. Although PERIOD (PER) is known to initiate transcriptional repression by displacing the transcription activator CLOCK:BMAL1 from DNA, the underlying mechanism remains unknown. Using the monarch butterfly as a model harboring a simplified version of the mammalian circadian clock, we demonstrate that the binding of heat shock protein 68 (HSP68) to a region homologous to CLOCK mouse exon 19 is essential for CLK–PER interaction and PER repression. We further show that CLK–PER interaction and PER repression are promoted by the methylation of a single arginine methylation site (R45) on HSP68 via TRITHORAX catalytic activity.

published proceedings

  • Proc Natl Acad Sci U S A

author list (cited authors)

  • Zhang, Y., Iiams, S. E., Menet, J. S., Hardin, P. E., & Merlin, C.

complete list of authors

  • Zhang, Ying||Iiams, Samantha E||Menet, Jerome S||Hardin, Paul E||Merlin, Christine

publication date

  • January 1, 2022 11:11 AM