This gene encodes a member of the G-protein coupled receptor 1 family. The encoded protein is a receptor for the lysophospholipid sphingosine 1-phosphate. The encoded protein is one of the predominant sphingosine 1-phosphate G-protein coupled receptors expressed in T cells, and it plays a role in suppression of T cell proliferation, generation of cytokines, and potentially other aspects of immune activation. [provided by RefSeq, Feb 2010]