Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1074/jbc.M115.709659
Title (Primary) Rearrangement of the extracellular domain/extracellular loop 1 interface is critical for thyrotropin receptor activation
Author Schaarschmidt, J.; Nagel, M.B.M.; Huth, S.; Jaeschke, H.; Moretti, R.; Hintze, V.; von Bergen, M.; Kalkhof, S.; Meiler, J.; Paschke, R.
Source Titel Journal of Biological Chemistry
Year 2016
Department SUV; MOLSYB
Volume 291
Page From 14095
Page To 14108
Language englisch
UFZ wide themes RU3;
Abstract The thyroid stimulating hormone receptor (TSHR) is a G protein-coupled receptor (GPCR) with a characteristic large extracellular domain (ECD). TSHR activation is initiated by binding of the hormone ligand TSH to the ECD. How the extracellular binding event triggers the conformational changes in the transmembrane domain (TMD) necessary for intracellular G protein activation is poorly understood. To gain insight in this process, the knowledge on the relative positioning of ECD and TMD and the conformation of the linker region at the interface of ECD and TMD are of particular importance. To generate a structural model for the TSHR we applied an integrated structural biology approach combining computational techniques with experimental data. Chemical cross-linking followed by mass spectrometry yielded 17 unique distance restraints within the ECD of the TSHR, its ligand TSH, and the hormone-receptor complex. These structural restraints generally confirm the expected binding mode of TSH to the ECD as well as the general fold of the domains and were used to guide homology modeling of the ECD. Functional characterization of TSHR mutants confirms the previously suggested close proximity of Ser-281 and Ile-486 within the TSHR. Rigidifying this contact permanently with a disulfide bridge disrupts ligand-induced receptor activation and indicates that rearrangement of the ECD/extracellular loop 1 (ECL1) interface is a critical step in receptor activation. The experimentally verified contact of Ser-281 (ECD) and Ile-486 (TMD) was subsequently utilized in docking homology models of the ECD and the TMD to create a full-length model of a glycoprotein hormone receptor.
Persistent UFZ Identifier
Schaarschmidt, J., Nagel, M.B.M., Huth, S., Jaeschke, H., Moretti, R., Hintze, V., von Bergen, M., Kalkhof, S., Meiler, J., Paschke, R. (2016):
Rearrangement of the extracellular domain/extracellular loop 1 interface is critical for thyrotropin receptor activation
J. Biol. Chem. 291 , 14095 - 14108 10.1074/jbc.M115.709659