Cytoplasmic nuclear translocation of the HSP70 protein during enviromental stress in Trypanosoma cruzi

Abstract

The present study provides immunological evidence of the constitutive presence of the Hsp70 protein in the cytoplasm of logarithmically growing parasites cultured at the normal temperature of 28°C and of the translocation of the protein to the nucleus upon a heat shock treatment (2 hours at 37°C). The nuclear translocation of the protein must depend on other factors beside the temperature per se since at 28°C, in stationary phase growing parasites, the Hsp70 protein was present in both the cytoplasm and the nucleus. During recovery at 28°C the protein leaves the nuclei but the nuclear-cytoplasmic translocation of the protein is a much more gradual process than its initial transport to the nucleus. Since the isoform of the nuclear Hsp70 is different from that found in the cytoplasm it is likely that before translocation to the nucleus the cytoplasmic Hsp70 nuclear precursor must undergo a specific modification