In C.elegans, odr-4 and odr-8 are required for localising a subset of odorant GPCRs to the cilia of olfactory neurons [1]. Olfactory receptors (ORs) are synthesised in endoplasmic reticulum of the olfactory neurons, trafficked to the cell surface membrane and transported to the tip of the olfactory cilium, where they bind with odorants. Various accessory proteins are required for proper targetting of different ORs to the cell membrane. ODR-4 was the first accessory protein to be described.

1: Odorant receptor localization to olfactory cilia is mediated by ODR-4, a novel membrane-associated protein. Dwyer ND, Troemel ER, Sengupta P, Bargmann CI; Cell. 1998;93:455-466. PMID:9590179