UAS regulates expression of the Tag:HA-tagged Hnf4 ORF containing the R167W mutation, which corresponds to the R85W mutation in human 'HNF4A' (aka'MODY1') associated with Fanconi renotubular syndrome (FRTS). This construct also contains a S169A mutation, which is equivalent to S87A in human 'HNF4A' (aka'MODY1'), thus suppressing PKC-dependent phosphorylation at that position and thereby also suppressing Hnf4 nuclear export and consequent cytotoxic effects.
Third instar larval garland nephrocytes expressing Hnf4R167W.S169A.UAS.Tag:HA under the control of Scer\GAL4Ugt36A1.PK exhibit a severe increase in lipid droplet content (BODIPY staining), but normal ER distribution, as compared to controls; upon Scer\GAL4sns.GCN-driven expression, there are no changes in pericardial nephrocyte viability, as compared to controls.