Phospho-Histone H2A.X (Ser139) Polyclonal Antibody, Rockland™

Description

• Store vial at -20°C prior to opening
• Aliquot contents and freeze at -20°C or below for extended storage
• Avoid cycles of freezing and thawing
• Centrifuge product if not completely clear after standing at room temperature
• This product is stable for several weeks at 4°C as an undiluted liquid
• Dilute only prior to immediate use
• H2AX pS139 is directed against the phosphorylated form of human H2AX protein at the pS139 residue
• Reactivity with non-phosphorylated human H2AX is minimal by ELISA and western blot
• A BLAST analysis was used to suggest 100% cross reactivity with H2AX from human based on the sequence homology with the immunogen
• Reactivity against homologues from other sources is not known
• Histone H2A.X (H2AX) is a member of the histone H2A family which is one of the four core histones making up the nucleosome core particle
• In eukaryotes, DNA double strand breaks (DSBs) have been shown to trigger the phosphorylation of serine 139 at the carboxy terminus of histone H2AX resulting in gamma-H2AX
• The phosphorylation of H2AX can be detected by Western blotting or immunofluorescence, revealing the frequency of DSBs
• The phosphatidylinositol 3-kinases have been implicated in H2AX phosphorylation, but it is unclear if ATM is the primary H2AX kinase or if other members of the family such as DNA-PK and ATR contribute in a similar manner
• Structurally, H2A.x contains 143 amino acid residues
• Histone H2A.X is considered a basal histone, being synthesized in G1 as well as in S-phase, and its mRNA contains polyA addition motifs and a polyA tail along with the conserved stem-loop and U7 binding sequences involved in the processing and stability of replication type histone mRNAs
• There are two forms of Histone H2A.X mRNA, one about 1600 bases long and contains polyA; the other about 575 bases long, lacking polyA
• The short form behaves as a replication type histone mRNA, while the longer behaves as a basal type histone mRNA
• Histone H2A.X maps to the 11q23.2-q23.3 region of the human chromosome
• Histone H2A.x contributes to histone-formation and therefore the structure of DNA
• Histone H2A variant H2A.x specifically regulates the interaction of MDC1 (mediator of DNA damage checkpoint protein 1), a DNA repair protein to the sites of DNA damage.