Rabbit Polyclonal Chk1(Phospho-Ser317) Antibody

The Chk1 (Phospho-Ser317) antibody detects the activated form of checkpoint kinase 1 (Chk1), a key regulator of the DNA damage response (DDR). Chk1 is a serine/threonine kinase primarily activated in response to replication stress or DNA damage, which triggers the ATR-mediated phosphorylation of Ser317 (and Ser345) to initiate cell cycle arrest, DNA repair, or apoptosis. This phosphorylation event promotes Chk1 dissociation from chromatin, enabling interaction with downstream targets like CDC25 phosphatases to block cell cycle progression (e.g., G2/M arrest). The Chk1 (Phospho-Ser317) antibody specifically recognizes this phosphorylation site, serving as a critical tool for studying DDR activation in experimental models. It is widely used in Western blotting, immunofluorescence, and immunoprecipitation to assess Chk1 activity in contexts such as cancer therapy (e.g., after chemotherapy or radiation), replication stress, or checkpoint dysregulation. Validations often include loss of signal in phosphatase-treated samples or Chk1-deficient cells. Researchers use this antibody to explore mechanisms of genome stability, drug resistance, or synergistic effects with DDR-targeted therapies. Optimal detection typically requires cell/tissue lysis buffers with phosphatase inhibitors to preserve phosphorylation status.