Consistent with these findings, a recent study reported that polyQ-expanded ataxin-3 with the K117 residue mutated to prevent ubiquitination at the site, is more toxic than polyQ-expanded ataxin-3 with an intact K117 residue in Drosophila, further suggesting that ubiquitination at K117 is protective in MJD [171]. Here, ATXN3 is linked to Machado-Joseph disease.