Checkpoint kinases (Chks) are protein kinases that are involved in cell cycle control. Two checkpoint kinase subtypes have been identified, Chk1 and Chk2. Chk1 is a central component of genome surveillance pathways and is a key regulator of the cell cycle and cell survival. Chk1 is required for the initiation of DNA damage checkpoints and has recently been shown to play a role in the normal (unperturbed) cell cycle. Chk1 impacts various stages of the cell cycle including the S phase, G2/M transition and M phase.In addition to mediating cell cycle checkpoints, Chk1 also contributes to DNA repair processes, gene transcription, egg production, embryo development, cellular responses to HIV infection and somatic cell viability.
Background References
1. Dent P. Investigational CHK1 inhibitors in early phase clinical trials for the treatment of cancer. Expert Opin Investig Drugs. 2019 Dec;28(12):1095-1100. doi: 10.1080/13543784.2019.1694661. Epub 2019 Nov 29. PMID: 31783714.
2. Carrassa L, Damia G. Unleashing Chk1 in cancer therapy. Cell Cycle. 2011 Jul 1;10(13):2121-8. doi: 10.4161/cc.10.13.16398. Epub 2011 Jul 1. PMID: 21610326.
Subcellular Location
Nucleus, Chromosome, Cytoplasm, cytoskeleton, microtubule organizing center, centrosome
Western blot analysis of Chk1 on different lysates with Rabbit anti-Chk1 antibody (HA722855) at 1/1,000 dilution.
Lane 1: HeLa cell lysate Lane 2: K-562 cell lysate Lane 3: A431 cell lysate Lane 4: NIH/3T3 cell lysate Lane 5: PC-12 cell lysate
Lysates/proteins at 20 µg/Lane.
Predicted band size: 54 kDa Observed band size: 54 kDa
Exposure time: 25 seconds; ECL: K1801;
4-20% SDS-PAGE gel.
Proteins were transferred to a PVDF membrane and blocked with 5% NFDM/TBST for 1 hour at room temperature. The primary antibody (HA722855) at 1/1,000 dilution was used in 5% NFDM/TBST at 4℃ overnight. Goat Anti-Rabbit IgG - HRP Secondary Antibody (HA1001) at 1/50,000 dilution was used for 1 hour at room temperature.
Immunocytochemistry analysis of HeLa cells labeling Chk1 with Rabbit anti-Chk1 antibody (HA722855) at 1/50 dilution.
Cells were fixed in 4% paraformaldehyde for 15 minutes at room temperature, permeabilized with 0.1% Triton X-100 in PBS for 5 minutes at room temperature, then blocked with 1% BSA in 10% negative goat serum for 1 hour at room temperature. Cells were then incubated with Rabbit anti-Chk1 antibody (HA722855) at 1/50 dilution in 1% BSA in PBST overnight at 4 ℃. Goat Anti-Rabbit IgG H&L (iFluor™ 488, HA1121) was used as the secondary antibody at 1/1,000 dilution. PBS instead of the primary antibody was used as the secondary antibody only control. Nuclear DNA was labelled in blue with DAPI.
Beta tubulin (M1305-2, red) was stained at 1/100 dilution overnight at +4℃. Goat Anti-Mouse IgG H&L (iFluor™ 594, HA1126) was used as the secondary antibody at 1/1,000 dilution.
Chk1 was immunoprecipitated from 0.2 mg HeLa cell lysate with HA722855 at 2 µg/10 µl beads. Western blot was performed from the immunoprecipitate using HA722855 at 1/1,000 dilution. Anti-Rabbit IgG for IP, AlpSdAbs® VHH(HRP) (025-100-005) at 1/5,000 dilution was used for 1 hour at room temperature.
Lane 1: HeLa cell lysate (input) Lane 2: HA722855 IP in HeLa cell lysate Lane 3: Rabbit IgG instead of HA722855 in HeLa cell lysate