mouse PERIOD proteins (mPER1 and mPER2), CLOCK, and BMAL1 undergo robust
circadian changes in phosphorylation. These proteins, the cryptochromes (mCRY1 and
mCRY2), and casein kinase I epsilon (CKIϵ) form multimeric complexes that are bound to
DNA during negative transcriptional feedback. CLOCK: BMAL1 heterodimers remain bound
to DNA over the circadian cycle. The temporal increase in mPER abundance controls the …