Receptor for the neuroprotective and glioprotective factor prosaposin. Ligand binding induces endocytosis, followed by an ERK phosphorylation cascade. Forms a complex with PRKN, STUB1 and HSP70. The amount of STUB1 in the complex increases during ER stress. STUB1 promotes the dissociation of HSP70 from PRKN, thus facilitating PRKN-mediated GPR37 ubiquitination. Interacts with PACRG. Expressed in brain and spinal cord, and at lower levels in testis, placenta and liver, but no detectable expression observed in any other tissue. When overexpressed in cells, tends to become insoluble and unfolded. Accumulation of the unfolded protein may lead to dopaminergic neuronal death in juvenile Parkinson disease (PDJ). Ubiquitinated by PRKN in the presence of UBE2E1 and UBE2L3 in the endoplasmic reticulum. The unfolded form is specifically ubiquitinated by SYVN1, which promotes its proteasomal degradation and prevents neuronal cell death. Belongs to the G-protein coupled receptor 1 family.