Involved in the fz signaling pathway that controls wing tissue polarity. Also mediates homophilic cell adhesion. May play a role in initiating prehair morphogenesis. May play a critical role in tissue polarity and in formation of normal dendrite fields. During planar cell polarity, stabilizes asymmetric PCP domains together with ATP6AP2 (PubMed:23292348). Interacts with ATP6AP2 (via N-terminus). Co-localizes at the apical junctions with ATP6AP2. In the pupal wing, expressed at relatively even levels in all regions. Abundant in 6-9 hours embryos. Expressed at higher levels in pupae than larvae. At 12 hours after puparium formation (apf), expressed evenly at cell boundaries. By 30 hours apf, expression is concentrated at proximal and distal cell boundaries with little or no expression at anterior and posterior boundaries. When prehairs emerge at 30-36 hours apf, expression becomes evenly distributed again along the whole cell boundary. Belongs to the G-protein coupled receptor 2 family.