According to these guidelines, a receptor is to be named with the abbreviation of the natural agonist with the highest potency, followed by a subscripted arabic number. The conceptualized 400-amino acid rat Edg8 protein shares 42 to 49% amino acid identity with the human S1P receptors EDG1, EDG3, and EDG5. Binding analysis confirmed that expression of Edg8 leads to high-affinity binding for labeled S1P.Widely expressed in the brain, most prominently in the corpus callosum, which is predominantly white matter. Detected in spleen, peripheral blood leukocytes, placenta, lung, aorta, and fetal spleen. Low-level signal detected in many tissue extracts. Isoform 1 is predominently expressed in peripheral tissues, whereas isoform 2 is expressed in brain, spleen and peripheral blood leukocytes.