title: Action of apoptotic endonuclease DNase gamma on naked DNA and chromatin substrates.
abstract: The internucleosomal cleavage of genomic DNA is a biochemical hallmark of apoptosis. DNase gamma, a Mg2+/Ca2+-dependent endonuclease, has been suggested to be one of the apoptotic endonucleases, but its biochemical characteristic has not been fully elucidated. Here, using recombinant DNase gamma, we showed that DNase gamma is a Mg2+/Ca2+-dependent single-stranded DNA nickase and has a high activity at low ionic strength. Under higher ionic strength, such as physiological buffer conditions, the endonuclease activity of DNase gamma is restricted, but its activity is enhanced in the presence of linker histone H1, which explains DNA cleavage at linker regions of apoptotic nuclei.
authors.affiliation: Research Institute for Biological Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan. mizuta@rs.noda.tus.ac.jp
authors.forename: Ryushin
authors.initials: R
authors.lastname: Mizuta
authors.forename: Midori
authors.initials: M
authors.lastname: Mizuta
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Araki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shiokawa
authors.forename: Sei-ichi
authors.initials: S
authors.lastname: Tanuma
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kitamura
mesh_terms: D017209:Apoptosis / Q000502:physiology; D001483:Base Sequence; D045744:Cell Line, Tumor; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D006657:Histones / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D013379:Substrate Specificity
chemical_list: D002843:Chromatin; D004277:DNA, Single-Stranded; D006657:Histones; D004247:DNA; D004706:Endodeoxyribonucleases; C105124:deoxyribonuclease gamma; D003850:Deoxyribonuclease I