title: Apoptotic release of histones from nucleosomes.
abstract: Chromatin structure is influenced by histone modification, and this may help direct chromatin behavior to facilitate transcription, DNA replication, and DNA repair. Chromatin condensation and DNA fragmentation are the classic nuclear features but remain poorly characterized. It is highly probable that nucleosomal structure must be altered to allow these features to become apparent, but data to support this construct are lacking. We report here that in response to apoptotic signals from a death receptor (CD95 and tumor necrosis factor-alpha) or mitochondrial (staurosporine) apoptotic stimulus, the core nucleosomal histones H2A, H2B, H3, and H4 become separated from DNA during apoptosis in Jurkat and HeLa cells and are consequently detectable in the cell lysate prepared using a non-ionic detergent. The timing of this histone release from DNA correlates well with the progression of apoptosis. We also show expression of a caspase cleavage-resistant form of ICAD (ICAD-DM) in Jurkat and HeLa cells abolished DNA fragmentation and also dramatically reduced histone release in apoptotic cells. However, we demonstrate that apoptotic histone release is not an inevitable consequence of CAD/DFF-40-mediated DNA destruction as DNA fragmentation but not histone release occurs efficiently in tumor necrosis factor-alpha- and etoposide-treated NIH3T3 cells. Furthermore, in an in vitro apoptotic assay, incubation of apoptotic Jurkat cellular extract with non-apoptotic Jurkat nuclei led to nuclear DNA fragmentation without obvious histone release. Taken together, these data demonstrate that CAD/DFF-40 functions indirectly in mediating nucleosomal destruction during apoptosis.
authors.affiliation: Department of Medicine and Department of Surgery, McMaster University, St. Joseph's Hospital, Hamilton, Ontario L8N 1Y2, Canada.
authors.forename: Dongcheng
authors.initials: D
authors.lastname: Wu
authors.forename: Alistair
authors.initials: A
authors.lastname: Ingram
authors.forename: Jill H
authors.initials: JH
authors.lastname: Lahti
authors.forename: Brie
authors.initials: B
authors.lastname: Mazza
authors.forename: Jose
authors.initials: J
authors.lastname: Grenet
authors.forename: Anil
authors.initials: A
authors.lastname: Kapoor
authors.forename: Lieqi
authors.initials: L
authors.lastname: Liu
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Kidd
authors.forename: Damu
authors.initials: D
authors.lastname: Tang
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D053938:DNA Fragmentation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D020287:In Situ Nick-End Labeling; D019169:Jurkat Cells; D051379:Mice; D009707:Nucleosomes / Q000378:metabolism*; D011485:Protein Binding; D012190:Retroviridae / Q000235:genetics; D019311:Staurosporine / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
chemical_list: C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D002843:Chromatin; D004791:Enzyme Inhibitors; D006657:Histones; D009707:Nucleosomes; D013778:Tetrazolium Salts; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; D005047:Etoposide; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D019311:Staurosporine