NUCLEAR TRANSLOCATION OF CONSTITUTIVE HEAT-SHOCK-PROTEIN-70 DURING S-PHASE IN SYNCHRONOUS MACROPLASMODIA OF PHYSARUM-POLYCEPHALUM

The level of constitutive heat shock protein 70 (HSC70) in Physarum po lycephalum was analyzed by means of Western blots during the synchrono us cell cycle of macroplasmodia. Total amounts as well as nuclear and cytoplasmic contents were determined separately and evaluated densitom etrically. A drastic increase of nuclear HSC70 was observed 10-40 min after the initiation of S phase (600% of the M phase value) and therea fter a slow decline toward the next M phase. Total HSC levels showed a slight (30%) increase during S phase whereas cytoplasmic HSC70 was ab out 30% lower during S phase compared to mitosis.