UAS sequences regulate expression of the NbALFA nanobody, which has been mutated to carry 6 amino acid substitutions (T25V, R65V, T75R, C100V, Q116H and S124F), and is tagged with mCherry. The encoded mutant protein appears to be destabilized in the absence of Tag:ALFA (its target peptide), but also does not accumulate at the site of Tag:ALFA-tagged proteins, most likely due to loss of target affinity.