Differential Migration of Acylphosphatase Isoenzymes from Cytoplasm to Nucleus during Apoptotic Cell Death

Abstract

The subcellular distribution of both muscle and common type acylphosphatases was studied during apoptosis. Both isoenzymes were previously shown to havein vitronucleolytic activity having a pH optimum at 6.8. In this paper we demonstrate a nuclear migration of the muscle type isoenzyme in response to variuos apoptotic stimuli either in K562 or in Jurkat cells, while the common type acylphosphatase isoform remains cytoplasmatic under the same conditions. Furthermore, we present evidences of a directin vivointeraction between muscle acylphosphatase and two other DNAses of about 60 and 80 kDa in size. Our results are consistent with anin vivoinvolvement of the muscle isoform in apoptosis, possibly as a part of a multimeric protein complex that binds and hydrolyses DNA during this process.