Sphingosine-1-phosphate receptor 1 (S1PR1) (S1PR1)

Sphingosine-1-phosphate receptor 1 (S1PR1), also known as EDG1, is a G protein-coupled receptor essential for the regulation of lymphocyte egress from lymphoid tissues into the blood and lymph (UniProt P21453). It is primarily expressed on lymphocytes and endothelial cells, where it mediates signaling in response to the lipid mediator sphingosine-1-phosphate (S1P) (PubMed: 11777917). In autoimmune conditions such as multiple sclerosis and ulcerative colitis, S1PR1 serves as a key therapeutic target for immunomodulatory drugs like fingolimod and ozanimod (DrugBank: DB04741). These drugs typically act as functional antagonists; by binding to the receptor, they induce its internalization and subsequent degradation, thereby sequestering lymphocytes within lymph nodes and preventing them from reaching sites of inflammation (PubMed: 20559325). While the term "S1PR1 mRNA" refers to the genetic transcript, therapeutic intervention currently focuses on the protein receptor, although mRNA levels are often monitored as a biomarker of receptor expression and drug effect (PubMed: 29739444). The receptor also plays a vital role in vascular development and the maintenance of endothelial barrier function (PubMed: 11777917). Safety concerns associated with S1PR1 modulation include transient bradycardia and atrioventricular block upon treatment initiation, as well as risks of macular edema and increased susceptibility to infections (PubMed: 20559325).

Other names

EDG1S1P1CD363Endothelial differentiation gene 1Sphingosine 1-phosphate receptor 1

Functional antagonism via receptor internalization and degradation following initial agonism (PubMed: 20559325).