CHEK2 Protein, Mouse (sf9, His-GST)

CHEK2, a serine/threonine-protein kinase, stands as a crucial orchestrator of cellular responses to DNA double-strand breaks, contributing to checkpoint-mediated cell cycle arrest, DNA repair activation, and apoptosis. Upon activation, CHEK2 phosphorylates a myriad of effectors, particularly at the consensus sequence [L-X-R-X-X-S/T]. Its regulatory role extends to cell cycle checkpoint arrest, achieved through the inhibition of CDC25A, CDC25B, and CDC25C, leading to enhanced inhibitory tyrosine phosphorylation of CDK-cyclin complexes and impeding cell cycle progression. Furthermore, CHEK2 impacts DNA repair processes by phosphorylating BRCA2, facilitating the association of RAD51 with chromatin and promoting homologous recombination. Its influence on apoptosis is evident through the phosphorylation of key proteins, including p53/TP53, MDM4, and PML. CHEK2's tumor suppressor function is highlighted by its involvement in transcriptional regulation of pro-apoptotic genes and its potential role in mitotic spindle assembly by phosphorylating BRCA1. Notably, CHEK2's absence may contribute to chromosomal instability observed in certain cancer cells, emphasizing its multifaceted role in maintaining genomic integrity.