UAS regulatory sequences drive expression of a fusion protein consisting of amino acid residues 1-74 of RpL40, a Gln-Gln-Ser-Arg spacer, slowFT (a fluorescent timer protein that changes from blue to red emission over time, allowing protein turnover to be analysed) and the nSyb coding region. The RpL40 portion encodes ubiquitin (minus the C-terminal Gly residues, to prevent its removal by deubiquitinases), which targets the fusion protein for degradation.