title: The acid deoxyribonuclease of neutrophils: a possible participant in apoptosis-associated genome destruction.
abstract: Human neutrophils are terminally differentiated cells that spontaneously undergo apoptosis in tissue culture. Apoptosis in these cells can be delayed by culture in the presence of granulocyte colony-stimulating factor or other inflammatory mediators. Neutrophils were found to contain an acid endonuclease that appeared to be responsible for the internucleosomal DNA cleavage that accompanies apoptosis. As measured by a plasmid nicking assay, this endonuclease had a molecular weight (M(r)) of 35,000, a pH optimum of 5.5, and a threshold for activity of pH 6.6 to 6.8. It was weakly inhibited by divalent cations (Ca2+, Mg2+, and Zn2+) and more strongly inhibited by aurintricarboxylic acid and N-bromosuccinimide. DNA from neutrophils treated with nigericin in buffers of defined pH displayed nucleosomal ladders whose prominence varied with pH in a manner that paralleled the pH dependence of the plasmid cleavage assays, consistent with internucleosomal DNA cleavage by the acid endonuclease. We have previously shown that neutrophils undergo acidification to a pH value as low as 6.0 during apoptosis; we suggest that this endonuclease may be responsible for the DNA cleavage seen in apoptotic neutrophils.
authors.affiliation: Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Gottlieb
authors.forename: H A
authors.initials: HA
authors.lastname: Giesing
authors.forename: R L
authors.initials: RL
authors.lastname: Engler
authors.forename: B M
authors.initials: BM
authors.lastname: Babior
mesh_terms: D017209:Apoptosis; D002413:Cations, Divalent / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D002850:Chromatography, Gel; D004249:DNA Damage; D004706:Endodeoxyribonucleases / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D009550:Nigericin / Q000494:pharmacology
chemical_list: D002413:Cations, Divalent; D002843:Chromatin; D004706:Endodeoxyribonucleases; C019329:deoxyribonuclease II; D009550:Nigericin