Sgt1 interactome analysis under proteostatic stress and steady state conditions

Buildup of misfolded proteins are prevented by chaperone-assisted refolding and/or proteasome dependent degradation. The coordination of these two protein quality control (PQC) systems is not fully understood. We identified the essential Hsp90 co-chaperone Sgt1 as a new member of a general PQC linking folding and degradation. Upon proteostatic stress, e.g. heat shock, Sgt1 accumulates in an Hsp90- and proteasome dependent manner at an until now unknown spatial PQC compartment in both yeast and human cells. In order to find further components of this new PQC compartment we performed pull down experiments and a protein interaction analysis of cells expressing either GFP tagged Sgt1 (or GFP alone, as a negative control) that were either grown at 30°C or under heat shock conditions (42°C, 30 minutes).