CST, 44274SF, Phospho-Histone H2A.X (Ser139) (D1O9J) Mouse Monoclonal Antibody (BSA and Azide Free)

Monoclonal Antibody for studying H2AX (Ser139) phosphate. Validated for Western Blotting,ELISA+. Highly specific and rigorously validated in-house, Phospho-Histone H2A.X (Ser139) (D1O9J) Mouse Monoclonal Antibody (BSA and Azide Free) (CST #44274) is ready to ship. Product Usage Information This formulation is ideal for use with technologies requiring specialized or custom antibody labeling, including fluorophores, metals, lanthanides, and oligonucleotides. It is not recommended for ChIP, ChIP-seq, CUT&RUN or CUT&Tag assays. If you require a carrier free formulation for chromatin profiling, please contact us . Optimal dilutions/concentrations should be determined by the end user. BSA and Azide Free antibodies are quality control tested by size exclusion chromatography (SEC) to determine antibody integrity. Formulation Supplied in 1X PBS (10 mM Na 2 HPO 4 , 3 mM KCl, 2 mM KH 2 PO 4 , and 140 mM NaCl (pH 7.8)). BSA and Azide Free. Storage Store at -20°C. This product will freeze at -20°C so it is recommended to aliquot into single-use vials to avoid multiple freeze/thaw cycles. A slight precipitate may be present and can be dissolved by gently vortexing. This will not interfere with antibody performance. Specificity / Sensitivity Phospho-Histone H2A.X (Ser139) (D1O9J) Mouse Monoclonal Antibody (BSA and Azide Free) detects endogenous levels of H2A.X only when phosphorylated at Ser139. Species Reactivity: Human, Mouse Source / Purification Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Ser139 of human Histone H2A.X protein. Background Histone H2A.X is a variant histone that represents approximately 10% of the total H2A histone proteins in normal human fibroblasts (1). H2A.X is required for checkpoint-mediated cell cycle arrest and DNA repair following double-stranded DNA breaks (1). 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 (2,3). Within minutes following DNA damage, H2A.X is phosphorylated at Ser139 at sites of DNA damage to generate γ-H2A.X (4). 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 (1). 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 (JNK1) in response to UV-A irradiation, and p38 MAPK in response to serum starvation (5-8). H2A.X is constitutively phosphorylated on Tyr142 in undamaged cells by WSTF (Williams-Beuren syndrome transcription factor) (9,10). Upon DNA damage, and concurrent with phosphorylation of Ser139, Tyr142 is dephosphorylated at sites of DNA damage by recruited EYA1 and EYA3 phosphatases (9). 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 (9). 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 (9). Thus, it appears that the balance of H2A.X Tyr142 phosphorylation and dephosphorylation provides a switch mechanism to determine cell fate after DNA damage. Alternate Names H2A histone family member X; H2A histone family, member X; H2A.X; H2A.X variant histone; H2a/x; H2AFX; H2AX; H2AX histone; Histone H2A.x; Histone H2AX Specification REACTIVITY: H M SENSITIVITY: Endogenous MW (kDa): 15 Source/Isotype: Mouse IgG2a