Understanding the Structural Basis of Adhesion GPCR Functions.
Unlike conventional G-protein-coupled receptors (GPCRs), adhesion GPCRs (aGPCRs) have large extracellular regions that are autoproteolytically cleaved from their membrane-embedded seven-pass transmembrane helices. Autoproteolysis occurs within the conserved GPCR-Autoproteolysis INducing (GAIN) domain that is juxtaposed to the transmembrane domain and cleaves the last beta strand of the GAIN domain. The other domains of the extracellular region are variable and specific to each aGPCR and are likely involved in adhering to various ligands. Emerging evidence suggest that extracellular regions may modulate receptor function and that ligand binding to the extracellular regions may induce receptor activation via multiple mechanisms. Here, we summarize current knowledge about the structural understanding for the extracellular regions of aGPCRs and discuss their possible functional roles that emerge from the available structural information.
Department of Biochemistry and Molecular Biology, University of Chicago, 929 E. 57th Street, GCIS W210, Chicago, IL, 60637, USA. arac@uchicago.edu.
Demet
D
Araç
Institute for Bioanalytical Chemistry, Leipzig University, Deutscher Platz 5, Leipzig, 04103, Germany.
Norbert
N
Sträter
Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
Elena
E
Seiradake
D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011499:Protein Processing, Post-Translational; D059748:Proteolysis; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship
D008024:Ligands; D043562:Receptors, G-Protein-Coupled
FLRT; GAIN; Horm; Latrophilin; Lectin; Olfactomedin; Stachel; Super-complex; Tethered agonist; Unc5