(A) Immunoprecipitation (IP) after expression of empty vector pFLAG-CMV5a or FlagHDQ138 and AavLEA1-HA (left panels), Em-HA (middle panels), or HSP70-HA (right panels). IP was performed with anti-Flag-M2 affinity gel followed by immunoblotting with anti-HA antibody (top row of panels). The inputs from the total cell lysates were probed with antibodies against HA (middle row) or Flag (bottom row) to detect the molecular shield or chaperone, and the polyQ protein, respectively. The asterisks in the top left and top middle panels show the expected position of any HA signal. (B) Example FRET analysis of EGFP-HDQ74 (donor) and AavLEA1-mCherry (acceptor) interactions in a live cell, showing signal in the donor channel upon excitation at donor wavelength (dx/dm), signal in the acceptor channel upon excitation at acceptor wavelength (ax/am), and donor normalized and unmixed FRET transfer efficiency dFRET.