Product Description

Histone H2A.X Monoclonal Antibody

Product: Mouse IgG1. Liquid in PBS, pH 7.3, 30% glycerol, and 0.01% sodium azide.

Catalogue Numbers: MB66900-50, MB66900-100

Sizes: 50µl, 100µl

Swiss-Prot: P16104

Host: Mouse

Reactivity: Human

Applications: WB, IHC

Background: Histone H2A.X is a variant histone that represents approximately 10% of the total H2A histone proteins in normal human fibroblasts . H2A.X is required for checkpoint-mediated cell cycle arrest and DNA repair following double-stranded DNA breaks . DNA damage, caused by ionizing radiation, UV-light, or radiomimetic agents, results in rapid phosphorylation of H2A.X at Ser139 by PI3K-like kinases, including ATM, ATR, and DNA-PK . Within minutes following DNA damage, H2A.X is phosphorylated at Ser139 at sites of DNA damage . This very early event in the DNA-damage response is required for recruitment of a multitude of DNA-damage response proteins, including MDC1, NBS1, RAD50, MRE11, 53BP1, and BRCA1 . In addition to its role in DNA-damage repair, H2A.X is required for DNA fragmentation during apoptosis and is phosphorylated by various kinases in response to apoptotic signals. H2A.X is phosphorylated at Ser139 by DNA-PK in response to cell death receptor activation, c-Jun N-terminal Kinase in response to UV-A irradiation, and p38 MAPK in response to serum starvation . H2A.X is constitutively phosphorylated on Tyr142 in undamaged cells by WSTF (Williams-Beuren syndrome transcription factor) . Upon DNA damage, and concurrent with phosphorylation of Ser139, Tyr142 is dephosphorylated at sites of DNA damage by recruited EYA1 and EYA3 phosphatases . While phosphorylation at Ser139 facilitates the recruitment of DNA repair proteins and apoptotic proteins to sites of DNA damage, phosphorylation at Tyr142 appears to determine which set of proteins are recruited. Phosphorylation of H2A.X at Tyr142 inhibits the recruitment of DNA repair proteins and promotes binding of pro-apoptotic factors such as JNK1 . Mouse embryonic fibroblasts expressing only mutant H2A.X Y142F, which favors recruitment of DNA repair proteins over apoptotic proteins, show a reduced apoptotic response to ionizing radiation. Thus, it appears that the balance of H2A.X Tyr142 phosphorylation and dephosphorylation provides a switch mechanism to determine cell fate after DNA damage.

Product: Mouse IgG1. Liquid in PBS, pH 7.3, 30% glycerol, and 0.01% sodium azide.

Purification and Purity: This antibody is purified through a protein G column.

Specificity: Recognizes endogenous levels of Histone H2A.X protein.

Note: For research use only, not for use in diagnostic procedure.

Extra Notes: Western blot analysis of Histone H2A.X expression in 293 (A), CEM (B), HepG2 (C), Jurkat (D), Hela (E), Raji (F) whole cell lysates., Immunohistochemical analysis of Histone H2A.X staining in human thymus formalin fixed paraffin embedded tissue section. The section was pre-treated using heat mediated antigen retrieval with sodium citrate buffer (pH 6.0). The section was then incubated with the antibody at room temperature and detected using an HRP conjugated compact polymer system. DAB was used as the chromogen. The section was then counterstained with haematoxylin and mounted with DPX.

Bioworld Molecular Weight: ~ 15 kDa

Storage and Stability: Store at 4°C short term. Aliquot and store at -20°C long term. Avoid freeze-thaw cycles.

Alternative Name: H2AX; Histone H2AX; H2a/x; Histone H2A.X

Immunogen: KLH-conjugated synthetic peptide encompassing a sequence within the C-term region of human Histone H2A.X. The exact sequence is proprietary.

Conjugate: Unconjugated

Modification: Unmodified