The function of GPR142 (G protein-coupled receptor 142, ENSG00000257008) is as follows. Highly selective G protein-coupled receptor for aromatic amino acids specifically L-Tryptophan (L-Trp) and L-Phenylalanine (L- Phe), with L-Trp being the most potent and efficacious agonist (PubMed:27104960, PubMed:27322810). GPR142 agonists triggers the activation of both GNAQ/G(q) and GNAI1/G(i)-coupled signaling pathways (PubMed:27104960). L-Trp stimulates glucose-induced insulin secretion and triggers G(q)-mediated signaling (By similarity). GPR142 appears to have a role as a sensor of aromatic essential amino acids controlling the secretion of both insulin in the pancreas and other gastrointestinal hormones including glucagon but also CCK and incretin in the gastrointestinal-tract, contributing to the control of glucose homeostasis by coordinating pancreatic and gut hormone secretion (By similarity). {ECO:0000250|UniProtKB:Q7TQN9, ECO:0000269|PubMed:27104960, ECO:0000269|PubMed:27322810}.