G-protein coupled receptor expressed in lymphocytes that acts as a chemotactic receptor for B-cells, T-cells, splenic dendritic cells, monocytes/macrophages and astrocytes. Receptor for oxysterol 7-alpha,25-dihydroxycholesterol (7-alpha,25-OHC) and other related oxysterols. Mediates cell positioning and movement of a number of cells by binding the 7-alpha,25-OHC ligand that forms a chemotactic gradient. Binding of 7-alpha,25-OHC mediates the correct localization of B-cells during humoral immune responses. Guides B-cell movement along the B-cell zone-T-cell zone boundary and later to interfollicular and outer follicular regions. Its specific expression during B-cell maturation helps position B-cells appropriately for mounting T-dependent antibody responses. Collaborates with CXCR5 to mediate B-cell migration; probably by forming a heterodimer with CXCR5 that affects the interaction between of CXCL13 and CXCR5. Also acts as a chemotactic receptor for some T-cells upon binding to 7-alpha,25-OHC ligand. Promotes follicular helper T (Tfh) cells differentiation by positioning activated T-cells at the follicle-T-zone interface, promoting contact of newly activated CD4 T-cells with activated dendritic cells and exposing them to Tfh-cell-promoting inducible costimulator (ICOS) ligand. Expression in splenic dendritic cells is required for their homeostasis, localization and ability to induce B- and T-cell responses: GPR183 acts as a chemotactic receptor in dendritic cells that mediates the accumulation of CD4(+) dendritic cells in bridging channels. Regulates migration of astrocytes and is involved in communication between astrocytes and macrophages. Promotes osteoclast precursor migration to bone surfaces. Signals constitutively through G(i)-alpha, but not G(s)-alpha or G(q)-alpha. Signals constitutively also via MAPK1/3 (ERK1/2) 