UAS sequences regulate expression of a SPLICS (split-GFP-based contact site sensor) reporter that can be used to quantify contact between the endoplasmic reticulum (ER) and plasma membrane within a 8-10 nm range. The UAS sequences drive expression of two open reading frames separated by a P2A peptide (to ensure separate translation of the two ORFs and equimolar amounts of the two expressed proteins). The first ORF encodes a protein composed of an ER membrane targeting sequence, a 'short' spacer of 29 amino acids, and the spGFP11 split fragment. The second ORF encodes the spYFP1-10 split fragment tagged with sequence that anchors it to the inside of the plasma membrane. Where the ER and plasma membranes are in close proximity, the spYFP1-10 and spGFP11 moieties can self-assemble to reconstitute a functional protein, resulting in fluorescent puncta (details from PMID:33247103).