Cryptochrome 1 controls the body’s daily clock by interacting with the end part of BMAL1

CRY1 may regulate the circadian clock by competing with coactivators for binding to BMAL1, influencing the 24-hour cycle.

• CRY1 competes for binding with coactivators to the C-terminal transactivation domain of BMAL1.
• TAD mutations that change co-regulator affinities can alter the balance of activation and repression.
• These changes may affect the intrinsic circadian period or eliminate cycling.
• CRY1's role as a circadian repressor is linked to its ability to sequester the TAD from coactivators.
• Regulation of the BMAL1 TAD is suggested to be a critical mechanism for circadian timing.

Simplified