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Product Name
CHK2, active
Catalog Number
E-K013
Unit Price
$275.00
Quantity
10.0 ug
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Recombinant full length human CHK2 containing N-terminal GST tag was expressed by baculovirus in Sf 9 insect cells.
The gene accession number is NM_007194.
This material is sold for research purposes only.
Specific Activity
142 nmol phosphate incorporated into CHKtide per minute per mg protein at 30°C for 15 minutes using a final concentration of 50 µM ATP (0.83 µCi/assay). |
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| Scientific Background: |
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—Chk2 is the mammalian homolog of the Saccharomyces cerevisiae Rad53 and Schizosaccharomyces pombe Cds1 protein kinases required for the DNA damage and replication checkpoints. Chk2 is rapidly phosphorylated and activated in response to replication blocks and DNA damage; the response to DNA damage occurs in an ataxia telangiectasia mutated (ATM)-dependent manner (1). In vitro, Chk2 phosphorylates p53 on Ser-20 and dissociated preformed complexes of p53 with Mdm2, a protein that targets p53 for degradation (2). In vivo, ectopic expression of wild-type Chk2 leads to increased p53 stabilization after DNA damage, whereas expression of a dominant-negative Chk2 mutant abrogated both phosphorylation of p53 on Ser-20 and p53 stabilization. Thus, in response to DNA damage, Chk2 stabilizes the p53 tumor suppressor protein leading to cell cycle arrest in G1. Chk2 is directly phosphorylated by ATM in response to ionizing radiation (3). The phosphorylation occurs in the Ser-Gln/Thr-Gln (SQ/TQ) cluster domain (SCD) on Chk2, which contains seven SQ/TQ motifs, and Thr68 is the major in vitro phosphorylation site by ATM.
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| Storage: |
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—Store product frozen at or below -70°C. Stable for 1 year at -70°C as undiluted stock. Aliquot to avoid repeated thawing and freezing.
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| References: |
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—1. Matsuoka S, Huang M, Elledge SJ. Linkage of ATM to cell cycle regulation by the Chk2 protein kinase. Science. 1998 Dec 4;282(5395):1893-7. 2. Chehab NH, Malikzay A, Halazonetis TD. Chk2/hCds1 functions as a DNA damage checkpoint in G(1) by stabilizing p53. Genes Dev. 2000 Feb 1;14(3):278-88. 3. Matsuoka S, Rotman G, Ogawa A, Shiloh Y, Tamai K, Elledge SJ. Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro. Proc Natl Acad Sci U S A. 2000 Sep 12;97(19):10389-94.
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