A Demonstration of Several Deoxyribonuclease Activities in Mammalian Cell Mitochondria

Abstract

Extracts of purified mitochondria from adult rabbit liver and kidney have been prepared by lysis with Triton X-100. Such extracts contain deoxyribonuclease activity demonstrable at alkaline pH. Studies utilizing the effects of substrate variation, differing ionic strength, nucleoside di-and triphosphates, and S H -g r o u p inhibitors reveal the existence of at least five distinguishable deoxyribonuclease activities in these extracts.Assay of lysosomal and mitochondrial enzyme m a r k e r s indicates no significant lysosomal contamination of the mitochondrial extracts. Further studies also suggest that the alkaline deoxyribonuclease activity is specifically located in or in association with mitochondria.

Sequence and expression ofNUC1, the gene encoding the mitochondrial nuclease inSaccharomyces cerevisiae

“…Similar potent DNase and RNase activities have been observed in other eukaryotes (5,6), although only an enzyme from Neurospora crassa has been completely purified (7). A partially purified enzyme preparation from beef heart mitochondria has also recently been characterized (8,9).…”

Purification and properties of a single strand-specific endonuclease from mouse cell mitochondria

“…The association of a significant proportion of the total cellular alkaline DNase activity with mitochondria has been demonstrated in yeast (17)(18)(19), Neurospora crassa (1,3) and mammalian cells (21)(22)(23)(24)(25). In this paper, we have presented evidence for the mitochondrial location of a single-strand specific alkaline endonuclease activity in cultured mouse plasmacytoma cells.…”

“…reported in 1959 (21). Although several distinguishable activities have since been characterized (22)(23)(24)(25), the resolution of any one of these from the others has not generally been achieved so that the relationships of activities to specific proteins or genes are unknown (25). In this report, we describe the purification and properties of a single-strand specific endonuclease from mouse cell mitochondria with properties remarkably like those described for the fungal enzymesin fact, the mouse enzyme shows weak cross-reactivity with antibody prepared against a mitochondrial single-strand DNase activity from N. crassa.…”

Novel Theranostic DNA Nanoscaffolds for the Simultaneous Detection and Killing of Escherichia coli and Staphylococcus aureus

“…Another distinction could be observed in the localization of DNase in mammalian and bacterial cells. Bacterial DNase can be found in their cell membrane, , whereas mammalian cells’ DNase is isolated in their nucleus and mitochondria. , This distinction would help to protect the DPAu/AMD from nuclease degradation while being in transit in mammalian cells; avoided unintended release of the drug cargo in cells and thus reduced potential cytotoxicity to the mammalian cells.…”