Characterization of the Hsp100 disaggregase from sugarcane (SHsp101) for chaperone like activity in a yeast system

The Hsp104/ClpB protein subfamily is unique in its ability to reactivate protein aggregates, which are implicated in several human and animal diseases. However, when compared to the unicellular yeast Hsp104 and bacterial ClpB disaggregases, the multicellular plant ortholog (Hsp101) is poorly studied. Here, we present a functional characterization of the Hsp101 (SHsp101) from the economically and agriculturally important sugarcane cultivar. Like Hsp104, SHsp101 has in vitro ATP/ATPγS dependent aggregate reactivation activity, confers induced thermotolerance in yeast and its ATPase activity is sensitive to guanidinium chloride. However, SHsp101 has distinct properties not previously reported for Hsp104, including higher ATPase activity at elevated temperatures and ATP independent intrinsic chaperone activity. Hence, SHsp101 has overlapping and distinct features from Hsp104.