Histones induce the release of apoptogenic factors from liver mitochondria

The effect of histones on the release of apoptogenic factors has been studied. The incubation of H1 histone or total histones with mitochondria from a rat liver results in their binding to mitochondria. Furthermore, histones induce the release of cytochrome c and a number of other proteins from the intermembranous space of mitochondria. Proteins released from mitochondria in the presence of histones exhibit apoptogenic activity and induce internucleosomal DNA fragmentation of thymus nuclei. The cytotoxic effect of histones is probably mediated by apoptogenic proteins, which are released from intermembranous space as a response of histone binding to mitochondria.