Abstract
Small heat shock proteins (sHSPs) are major stress proteins in higher plant cells, which are synthesized in response to high temperature and other kind of stress. sHSPs are classified into several types, which were found in a distinct cellular compartment including the cytosol, chloroplasts, ER and mitochondria.
We found a protein with the molecular mass of 15.7kDa in Arabidopsis that was homologous to sHSPs. This protein has an α-crystalline domain and a putative PTS (peroxisome targeting signal) in its C-terminal end. Cell fractionation and immunoblot analysis revealed that the 15.7-kDa protein localized in peroxisomes which were isolated from heat-treated plants. In vitro analysis showed that the recombinant 15.7-kDa protein were able to enhance the refolding of chemically denatured citrate synthase. These results indicated that the 15.7-kDa protein is a novel sHSP which are localized in peroxisomes.
