TY - JOUR
T1 - GPR161 structure uncovers the redundant role of sterol-regulated ciliary cAMP signaling in the Hedgehog pathway
AU - Hoppe, Nicholas
AU - Harrison, Simone
AU - Hwang, Sun Hee
AU - Chen, Ziwei
AU - Karelina, Masha
AU - Deshpande, Ishan
AU - Suomivuori, Carl Mikael
AU - Palicharla, Vivek R.
AU - Berry, Samuel P.
AU - Tschaikner, Philipp
AU - Regele, Dominik
AU - Covey, Douglas F.
AU - Stefan, Eduard
AU - Marks, Debora S.
AU - Reiter, Jeremy F.
AU - Dror, Ron O.
AU - Evers, Alex S.
AU - Mukhopadhyay, Saikat
AU - Manglik, Aashish
N1 - Publisher Copyright:
© The Author(s), under exclusive licence to Springer Nature America, Inc. 2024.
PY - 2024/4
Y1 - 2024/4
N2 - The orphan G protein-coupled receptor (GPCR) GPR161 plays a central role in development by suppressing Hedgehog signaling. The fundamental basis of how GPR161 is activated remains unclear. Here, we determined a cryogenic-electron microscopy structure of active human GPR161 bound to heterotrimeric Gs. This structure revealed an extracellular loop 2 that occupies the canonical GPCR orthosteric ligand pocket. Furthermore, a sterol that binds adjacent to transmembrane helices 6 and 7 stabilizes a GPR161 conformation required for Gs coupling. Mutations that prevent sterol binding to GPR161 suppress Gs-mediated signaling. These mutants retain the ability to suppress GLI2 transcription factor accumulation in primary cilia, a key function of ciliary GPR161. By contrast, a protein kinase A-binding site in the GPR161 C terminus is critical in suppressing GLI2 ciliary accumulation. Our work highlights how structural features of GPR161 interface with the Hedgehog pathway and sets a foundation to understand the role of GPR161 function in other signaling pathways.
AB - The orphan G protein-coupled receptor (GPCR) GPR161 plays a central role in development by suppressing Hedgehog signaling. The fundamental basis of how GPR161 is activated remains unclear. Here, we determined a cryogenic-electron microscopy structure of active human GPR161 bound to heterotrimeric Gs. This structure revealed an extracellular loop 2 that occupies the canonical GPCR orthosteric ligand pocket. Furthermore, a sterol that binds adjacent to transmembrane helices 6 and 7 stabilizes a GPR161 conformation required for Gs coupling. Mutations that prevent sterol binding to GPR161 suppress Gs-mediated signaling. These mutants retain the ability to suppress GLI2 transcription factor accumulation in primary cilia, a key function of ciliary GPR161. By contrast, a protein kinase A-binding site in the GPR161 C terminus is critical in suppressing GLI2 ciliary accumulation. Our work highlights how structural features of GPR161 interface with the Hedgehog pathway and sets a foundation to understand the role of GPR161 function in other signaling pathways.
UR - https://www.scopus.com/pages/publications/85184206276
U2 - 10.1038/s41594-024-01223-8
DO - 10.1038/s41594-024-01223-8
M3 - Article
C2 - 38326651
AN - SCOPUS:85184206276
SN - 1545-9993
VL - 31
SP - 667
EP - 677
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
IS - 4
ER -