Structure of S1PR2-heterotrimeric G13 signaling complex

  • Sci Adv. 2022 Apr;8(13):eabn0067. doi: 10.1126/sciadv.abn0067.
Hongwen Chen  1 ,  Kevin Chen  2 ,  Weijiao Huang  1 ,  Louis M Staudt  3 ,  Jason G Cyster  2  4 ,  Xiaochun Li  1  5
Affiliations
  • 1. Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
  • 2. Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA.
  • 3. Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
  • 4. Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, USA.
  • 5. Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
PMID: 35353559 DOI: 10.1126/sciadv.abn0067
Abstract

Sphingosine-1-phosphate (S1P) regulates immune cell trafficking, angiogenesis, and vascular function via its five receptors. Inherited mutations in S1P receptor 2 (S1PR2) occur in individuals with hearing loss, and acquired mutations in S1PR2 and Gα13 occur in a malignant lymphoma. Here, we present the cryo-electron microscopy structure of S1P-bound S1PR2 coupled to the heterotrimeric G13. Interaction between S1PR2 intracellular loop 2 (ICL2) and transmembrane helix 4 confines ICL2 to engage the α5 helix of Gα13. Transforming growth factor-α shedding assays and cell migration assays support the key roles of the residues in S1PR2-Gα13 complex assembly. The structure illuminates the mechanism of receptor disruption by disease-associated mutations. Unexpectedly, we showed that FTY720-P, an agonist of the Other four S1PRs, can trigger G13 activation via S1PR2. S1PR2F274I variant can increase the activity of G13 considerably with FTY720-P and S1P, thus revealing a basis for S1PR drug selectivity.