Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

Phospho-Chk2 (Thr68) Blocking Peptide #1255

Description

This peptide is used to block Phospho-Chk2 (Thr68) (80F5) Rabbit mAb #2584 reactivity.

Quality Control

The quality of this peptide was evaluated by reverse-phase HPLC and by mass spectrometry. The peptide blocks Phospho-Chk2 (Thr68) (80F5) Rabbit mAb #2584 signal completely in immunohistochemistry.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lung carcinoma, using Phospho-Chk2 (Thr68) (80F5) Rabbit mAb (#2584) in the presence of control peptide (left) or Phospho-Chk2 (Thr68) Blocking Peptide (right).

Applications

Use as a blocking reagent to evaluate the specificity of antibody reactivity in immunohistochemistry protocols.

Directions for Use

For immunohistochemistry, add twice the volume of peptide as volume of antibody used in 100 µl total volume. Incubate for a minimum of 30 minutes prior to adding the entire volume to the slide. Recommended antibody dilution can be found on the relevant product data sheet.

Background

Chk2 is the mammalian orthologue of the budding yeast Rad53 and fission yeast Cds1 checkpoint kinases (1-3). The amino-terminal domain of Chk2 contains a series of seven serine or threonine residues (Ser19, Thr26, Ser28, Ser33, Ser35, Ser50, and Thr68) each followed by glutamine (SQ or TQ motif). These are known to be preferred sites for phosphorylation by ATM/ATR kinases (4,5). After DNA damage by ionizing radiation (IR), UV irradiation, or hydroxyurea treatment, Thr68 and other sites in this region become phosphorylated by ATM/ATR (5-7). The SQ/TQ cluster domain, therefore, seems to have a regulatory function. Phosphorylation at Thr68 is a prerequisite for the subsequent activation step, which is attributable to autophosphorylation of Chk2 at residues Thr383 and Thr387 in the activation loop of the kinase domain (8).

  1. Allen, J.B. et al. (1994) Genes Dev. 8, 2401-2415.
  2. Weinert, T.A. et al. (1994) Genes Dev. 8, 652-665.
  3. Murakami, H. and Okayama, H. (1995) Nature 374, 817-819.
  4. Kastan, M.B. and Lim, D.S. (2000) Nat. Rev. Mol. Cell Biol. 1, 179-186.
  5. Matsuoka, S. et al. (2000) Proc. Natl. Acad. Sci. USA 97, 10389-10394.
  6. Melchionna, R. et al. (2000) Nat. Cell Biol. 2, 762-765.
  7. Ahn, J.Y. et al. (2000) Cancer Res. 60, 5934-5936.
  8. Lee, C.H. and Chung, J.H. (2001) J. Biol. Chem. 276, 30537-30541.

Application References

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For Research Use Only. Not For Use In Diagnostic Procedures.

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