Chk1 Protein, Mouse (sf9, His-GST)

Chk1, a serine/threonine-protein kinase, plays a crucial role in orchestrating checkpoint-mediated cell cycle arrest and facilitating DNA repair in response to DNA damage or unreplicated DNA. Additionally, it exerts negative regulation on cell cycle progression during unperturbed cell cycles, employing various mechanisms to safeguard genome integrity. Chk1 recognizes the substrate consensus sequence [R-X-X-S/T] and phosphorylates key targets such as CDC25A, CDC25B, CDC25C, and RAD51. Notably, phosphorylation of CDC25A and CDC25C creates binding sites for 14-3-3 proteins, inhibiting their activity and impeding cell cycle progression. Chk1's intricate involvement extends to the phosphorylation of TP53, promoting its activation, leading to cell cycle arrest, and suppressing cellular proliferation. Furthermore, Chk1 phosphorylates histone H3.1, influencing epigenetic regulation of gene expression. Its multifaceted role encompasses the phosphorylation of RB1, SPRTN, TLK1, and FANCE, contributing to the regulation of transcription, chromatin assembly, and DNA repair processes. Chk1 emerges as a pivotal player in maintaining genomic stability and orchestrating cellular responses to diverse challenges.