title: Heterotrimeric G protein beta1gamma2 subunits change orientation upon complex formation with G protein-coupled receptor kinase 2 (GRK2) on a model membrane.
abstract: Few experimental techniques can assess the orientation of peripheral membrane proteins in their native environment. Sum Frequency Generation (SFG) vibrational spectroscopy was applied to study the formation of the complex between G protein-coupled receptor (GPCR) kinase 2 (GRK2) and heterotrimeric G protein β(1)γ(2) subunits (Gβγ) at a lipid bilayer, without any exogenous labels. The most likely membrane orientation of the GRK2-Gβγ complex differs from that predicted from the known protein crystal structure, and positions the predicted receptor docking site of GRK2 such that it would more optimally interact with GPCRs. Gβγ also appears to change its orientation after binding to GRK2. The developed methodology is widely applicable for the study of other membrane proteins in situ.
authors.affiliation: Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, USA.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Boughton
authors.forename: Pei
authors.initials: P
authors.lastname: Yang
authors.forename: Valerie M
authors.initials: VM
authors.lastname: Tesmer
authors.forename: Bei
authors.initials: B
authors.lastname: Ding
authors.forename: John J G
authors.initials: JJ
authors.lastname: Tesmer
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
mesh_terms: D054769:G-Protein-Coupled Receptor Kinase 2 / Q000737:chemistry* / Q000378:metabolism*; D044387:GTP-Binding Protein beta Subunits / Q000737:chemistry* / Q000378:metabolism*; D044388:GTP-Binding Protein gamma Subunits / Q000737:chemistry* / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry; D008567:Membranes, Artificial; D008958:Models, Molecular; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D013057:Spectrum Analysis; D014732:Vibration
chemical_list: D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; D054769:G-Protein-Coupled Receptor Kinase 2; C028694:1-palmitoyl-2-oleoylphosphatidylcholine