Download MendeleyThe tethered peptide activation mechanism of adhesion GPCRs.
Barros-Alvarez, X., Nwokonko, R.M., Vizurraga, A., Matzov, D., He, F., Papasergi-Scott, M.M., Robertson, M.J., Panova, O., Yardeni, E.H., Seven, A.B., Kwarcinski, F.E., Su, H., Peroto, M.C., Meyerowitz, J.G., Shalev-Benami, M., Tall, G.G., Skiniotis, G.(2022) Nature 604: 757-762
- PubMed: 35418682
- DOI: https://doi.org/10.1038/s41586-022-04575-7
- Primary Citation of Related Structures:
7SF7, 7SF8 - PubMed Abstract:
Adhesion G-protein-coupled receptors (aGPCRs) are characterized by the presence of auto-proteolysing extracellular regions that are involved in cell-cell and cell-extracellular matrix interactions 1 . Self cleavage within the aGPCR auto-proteolysis-inducing (GAIN) domain produces two protomers-N-terminal and C-terminal fragments-that remain non-covalently attached after receptors reach the cell surface 1 . Upon dissociation of the N-terminal fragment, the C-terminus of the GAIN domain acts as a tethered agonist (TA) peptide to activate the seven-transmembrane domain with a mechanism that has been poorly understood 2-5 . Here we provide cryo-electron microscopy snapshots of two distinct members of the aGPCR family, GPR56 (also known as ADGRG1) and latrophilin 3 (LPHN3 (also known as ADGRL3)). Low-resolution maps of the receptors in their N-terminal fragment-bound state indicate that the GAIN domain projects flexibly towards the extracellular space, keeping the encrypted TA peptide away from the seven-transmembrane domain. High-resolution structures of GPR56 and LPHN3 in their active, G-protein-coupled states, reveal that after dissociation of the extracellular region, the decrypted TA peptides engage the seven-transmembrane domain core with a notable conservation of interactions that also involve extracellular loop 2. TA binding stabilizes breaks in the middle of transmembrane helices 6 and 7 that facilitate aGPCR coupling and activation of heterotrimeric G proteins. Collectively, these results enable us to propose a general model for aGPCR activation.
Organizational Affiliation:
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
