Anti-Histone H2A.X/H2AFX Antibody Picoband® Fluoro488 Conjugated

H2A histone family member X (usually abbreviated asH2AX) is a type of histone protein from the H2A family encoded by the H2AFX gene. Histones are basic nuclear proteins that are responsible for the nucleosome structure of the chromosomal fiber in eukaryotes. Two molecules of each of the four core histones (H2A, H2B, H3, and H4) form an octamer, around which approximately 146 bp of DNA is wrapped in repeating units, called nucleosomes. The linker histone, H1, interacts with linker DNA between nucleosomes and functions in the compaction of chromatin into higher order structures. This gene encodes a replication-independent histone that is a member of the histone H2A family, and generates two transcripts through the use of the conserved stem-loop termination motif, and the polyA addition motif.

Variant histone H2A which replaces conventional H2A in a subset of nucleosomes. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Required for checkpoint-mediated arrest of cell cycle progression in response to low doses of ionizing radiation and for efficient repair of DNA double strand breaks (DSBs) specifically when modified by C-terminal phosphorylation.

1. Rogakou EP, Pilch DR, Orr AH, Ivanova VS, Bonner WM (1998) . DNA double-stranded breaks induce histone H2AX phosphorylation on serine 139. J. Biol. Chem. 273 (10) : 5858–68. 2. Tanaka T, Halicka HD, Huang X, Traganos F, Darzynkiewicz Z. (2006) Constitutive histone H2AX phosphorylation and ATM activation, the reporters of DNA damage by endogenous oxidants. Cell Cycle. 5:1940-5. Epub 2006 Sep 1.