Disease relevance of H2afx

• Here we report that the Nijmegen breakage syndrome protein (Nbs1) and phosphorylated H2A histone family member X (gamma-H2AX, also known as gamma-H2afx), which facilitate DNA double-strand break (DSB) repair, form nuclear foci at the Ch region in the G1 phase of the cell cycle in cells undergoing CSR, and that switching is impaired in H2AX-/- mice [1].
• We have isolated a cDNA clone encoding a mouse histone H2A.X from a cDNA library of teratocarcinoma F9 cells [2].
• The expressed product of histone H2A.X cDNA in Escherichia coli showed remarkable stimulatory effects on growth of SC 115 cells cultured in the absence of testosterone [3].

High impact information on H2afx

• Hyperphosphorylation of histone H2A.X and dephosphorylation of histone H1 subtypes in the course of apoptosis [4].
• These results indicate that histone H2A.X is secreted from CS 2 cells cultured without testosterone and plays a role as a growth factor [3].
• Identification of histone H2A.X as a growth factor secreted by an androgen-independent subline of mouse mammary carcinoma cells [3].
• Regulation of the mouse histone H2A.X gene promoter by the transcription factor E2F and CCAAT binding protein [5].
• The promoter region of the H2A.X gene was characterized by chloramphenicol acetyltransferase analysis using Balb/c 3T3 cells [5].

Biological context of H2afx

• Maximal promoter activity was found in the construct containing up to -282 base pairs H2A.X upstream region [5].
• This permits us to assign the H2A.X gene to chromosome 9 and 11q23 in mouse and human, respectively [6].
• Endogenous H2A.X is expressed in type A spermatogonia through meiotic prophase spermatocytes in testis and in some somatic cells [7].
• Characterization of histone H2A.X expression in testis and specific labeling of germ cells at the commitment stage of meiosis with histone H2A.X promoter-enhanced green fluorescent protein transgene [7].

Associations of H2afx with chemical compounds

• On sodium dodecyl sulfate gels, one variant, H2A.X, has an apparent molecular weight approximately 1000 larger than H2A.1 and comprises approximately 11% of the total 2A in mouse L1210 cells [8].

Other interactions of H2afx

• The tryptic peptide patterns of the recently described H2A species H2A.X and H2A.Z from mouse were compared with the tryptic peptide patterns of the major mouse H2A's, H2A.1 and H2A [9].

References