title: Neuronal Calcium Sensor-1 Binds the D2 Dopamine Receptor and G-protein-coupled Receptor Kinase 1 (GRK1) Peptides Using Different Modes of Interactions.
abstract: Neuronal calcium sensor-1 (NCS-1) is the primordial member of the neuronal calcium sensor family of EF-hand Ca(2+)-binding proteins. It interacts with both the G-protein-coupled receptor (GPCR) dopamine D2 receptor (D2R), regulating its internalization and surface expression, and the cognate kinases GRK1 and GRK2. Determination of the crystal structures of Ca(2+)/NCS-1 alone and in complex with peptides derived from D2R and GRK1 reveals that the differential recognition is facilitated by the conformational flexibility of the C-lobe-binding site. We find that two copies of the D2R peptide bind within the hydrophobic crevice on Ca(2+)/NCS-1, but only one copy of the GRK1 peptide binds. The different binding modes are made possible by the C-lobe-binding site of NCS-1, which adopts alternative conformations in each complex. C-terminal residues Ser-178-Val-190 act in concert with the flexible EF3/EF4 loop region to effectively form different peptide-binding sites. In the Ca(2+)/NCS-1·D2R peptide complex, the C-terminal region adopts a 310 helix-turn-310 helix, whereas in the GRK1 peptide complex it forms an α-helix. Removal of Ser-178-Val-190 generated a C-terminal truncation mutant that formed a dimer, indicating that the NCS-1 C-terminal region prevents NCS-1 oligomerization. We propose that the flexible nature of the C-terminal region is essential to allow it to modulate its protein-binding sites and adapt its conformation to accommodate both ligands. This appears to be driven by the variability of the conformation of the C-lobe-binding site, which has ramifications for the target specificity and diversity of NCS-1.
authors.affiliation: From the NMR Centre for Structural Biology, Institute of Integrative Biology, and.
authors.forename: Sravan
authors.initials: S
authors.lastname: Pandalaneni
authors.affiliation: From the NMR Centre for Structural Biology, Institute of Integrative Biology, and the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, and.
authors.forename: Vijaykumar
authors.initials: V
authors.lastname: Karuppiah
authors.affiliation: the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, and.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Saleem
authors.affiliation: the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L37 4BY, United Kingdom.
authors.forename: Lee P
authors.initials: LP
authors.lastname: Haynes
authors.affiliation: the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L37 4BY, United Kingdom Burgoyne@liverpool.ac.uk.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Burgoyne
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB.
authors.forename: Olga
authors.initials: O
authors.lastname: Mayans
authors.affiliation: the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, and Jeremy.Derrick@manchester.ac.uk.
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Derrick
authors.affiliation: From the NMR Centre for Structural Biology, Institute of Integrative Biology, and Lu-Yun.Lian@liverpool.ac.uk.
authors.forename: Lu-Yun
authors.initials: LY
authors.lastname: Lian
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004298:Dopamine / Q000235:genetics / Q000378:metabolism; D051606:G-Protein-Coupled Receptor Kinase 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051580:Neuronal Calcium-Sensor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary / Q000235:genetics; D017448:Receptors, Dopamine D2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics
chemical_list: D002135:Calcium-Binding Proteins; C581293:DRD2 protein, human; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides; D010455:Peptides; D017448:Receptors, Dopamine D2; C101464:frequenin calcium sensor proteins; D051606:G-Protein-Coupled Receptor Kinase 1; C496764:GRK1 protein, human; D002118:Calcium; D004298:Dopamine
keywords: D2 dopamine receptor; G protein-coupled receptor (GPCR); GRK1; calcium; dopamine; neuronal calcium sensor-1; receptor internalization; x-ray crystallography