UAS regulatory sequences drive expression of RFP(Unk) that is tagged at the N-terminal end (via a AEAAAKEAAAKEAAAKA linker) with a Tag:Mito(hAKAP1) mitochondrial localization signal and at the C-terminal end with a 39 amino acid sequence from the Miga FFAT motif region (residues 229-267). The Miga FFAT sequence interacts with Vap33 protein (an endoplasmic reticulum protein), and thus the protein produced by this transgene can be used as a molecular tether between the endoplasmic reticulum and mitochondria.