Receptor for the lysosphingolipid sphingosine 1-phosphate (S1P). S1P is a bioactive lysophospholipid that elicits diverse physiological effect on most types of cells and tissues. Most abundant in heart, lung, kidney and spleen; low but detectable in brain, thymus, muscle and testis; and nearly undetectable in liver, stomach, and intestine. Expressed in embryonic lung from embryonic day 14-18. Also abundantly detected in embryonic nasal cartilage, sphenoid bone, vena cava, Meckel's cartilage/incisor teeth, genital tubercle and bladder. Belongs to the G-protein coupled receptor 1 family.