Action of apoptotic endonuclease DNase gamma on naked DNA and chromatin substrates.
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.
Mizuta
Ryushin
R
Research Institute for Biological Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan. mizuta@rs.noda.tus.ac.jp
Mizuta
Midori
M
Araki
Shinsuke
S
Shiokawa
Daisuke
D
Tanuma
Sei-ichi
S
Kitamura
Daisuke
D
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
D002843:Chromatin; D004277:DNA, Single-Stranded; D006657:Histones; D004247:DNA; D004706:Endodeoxyribonucleases; C105124:deoxyribonuclease gamma; D003850:Deoxyribonuclease I