Preferential accumulation of muscle type acylphosphatase in the nucleus during differentiation

In a previous paper we observed a direct involvement of acylphosphatase in differentiation, associated with enhanced levels of the enzyme in the cell. We have here investigated the subcellular localization of the two known ac ylphosphatase isoforms during this process. We show that in C2C12 myoblast cells, muscle type acylphosphatase accumulates in the nucleus during differ entiation. The same pattern of accumulation is observed also in K562 erythr oleukemia cells, although at a lower extent: this fact indicates that this phenomenon is not restricted to muscular cells but rather it could be of ge neral importance in the differentiative process. The common type acylphosph atase, showing an 8-fold increase in the cytoplasm during differentiation, does not accumulate in the nucleus, suggesting distinct roles of the two is oenzymes in this process.