The function of ENSG00000163328 (GPR155, G protein-coupled receptor 155) is as follows. Cholesterol-binding protein that acts as a regulator of mTORC1 signaling pathway (PubMed:36007018). Acts as a sensor of cholesterol to signal cholesterol sufficiency to mTORC1: in presence of cholesterol, binds cholesterol, leading to disruption of the interaction between the GATOR1 and KICSTOR complexes and promotion of mTORC1 signaling (PubMed:36007018, PubMed:39358511). Upon cholesterol starvation, GPR155/LYCHOS is unable to perturb the association between GATOR1 and KICSTOR, leading to mTORC1 signaling inhibition (PubMed:36007018). Binds indole-3-acetic acid and may play a role in tryptophan metabolism (PubMed:39358511). {ECO:0000269|PubMed:36007018, ECO:0000269|PubMed:39358511}.