The orphan GPR50 receptor promotes constitutive TGFβ receptor signaling and protects against cancer development
- Nat Commun. 2018 Mar 23;9(1):1216. doi: 10.1038/s41467-018-03609-x.
- 1. Inserm, U1016, Institut Cochin, Paris, 75014, France.
- 2. CNRS UMR 8104, Paris, 75014, France.
- 3. Université Paris Descartes, Université Sorbonne Paris Cité, Paris, 75006, France.
- 4. Hôpital Necker, CNRS UMR 8147, Paris, 75015, France.
- 5. Jean-Pierre Aubert Research Center, U837, Lille, France.
- 6. Plateforme Proteomique 3P5 de l'Université Paris Descartes, Paris, 75014, France.
- 7. Sorbonne Université, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), 75012, Paris, France.
- 8. Institut de Recherches SERVIER, Suresnes, 92150, France.
- 9. Inserm, U1016, Institut Cochin, Paris, 75014, France. [email protected].
- 10. CNRS UMR 8104, Paris, 75014, France. [email protected].
- 11. Université Paris Descartes, Université Sorbonne Paris Cité, Paris, 75006, France. [email protected].
Transforming growth factor-β (TGFβ) signaling is initiated by the type I, II TGFβ receptor (TβRI/TβRII) complex. Here we report the formation of an alternative complex between TβRI and the orphan GPR50, belonging to the G protein-coupled receptor super-family. The interaction of GPR50 with TβRI induces spontaneous TβRI-dependent Smad and non-Smad signaling by stabilizing the active TβRI conformation and competing for the binding of the negative regulator FKBP12 to TβRI. GPR50 overexpression in MDA-MB-231 cells mimics the anti-proliferative effect of TβRI and decreases tumor growth in a xenograft mouse model. Inversely, targeted deletion of GPR50 in the MMTV/Neu spontaneous mammary Cancer model shows decreased survival after tumor onset and increased tumor growth. Low GPR50 expression is associated with poor survival prognosis in human breast Cancer irrespective of the breast Cancer subtype. This describes a previously unappreciated spontaneous TGFβ-independent activation mode of TβRI and identifies GPR50 as a TβRI co-receptor with potential impact on Cancer development.