Abstract
All organisms synthesize heat-shock proteins (HSPs) in response to supraoptimal temperatures and other types of stress. Most of them act as molecular chaperones aiding other proteins to maintain or regain their native conformation by stabilizing partially unfolded states. The small HSPs (sHSPs) that range in size from approximately 15-30kDa have a conserved C-terminal region called alpha-crystallin domain. Small HSPs found in a distinct cellular compartment including the cytosol, chloroplast, ER and mitochondrion. However, the peroxisomal proteins that are homologous to sHSPs were not identified.
We found a protein with the molecular mass of 15.7 kDa in Arabidopsis, which has the putative PTS (peroxisome targeting signal) in its C-terminal end. The 15.7-kDa protein has alpha-crystallin domain and its mRNA is accumulated in heat-shock treated leaves. Now, we are analyzing about its localization in cell and its functions.
