Checkpoint kinase 1 (CHK1) is a serine/threonine-specific protein kinase that plays a crucial role in the DNA damage response (DDR) pathway. It is a key regulator of cell cycle checkpoints, particularly the intra-S and G2/M checkpoints, and is activated in response to DNA damage. By halting cell cycle progression, CHK1 allows time for DNA repair mechanisms to correct errors, thus maintaining genomic stability.
