Mini-G proteins are the engineered GTPase domains of Gα subunits. They couple to GPCRs and recapitulate the increase in agonist affinity observed upon coupling of a native heterotrimeric G protein. Given the small size and stability of mini-G proteins, and their ease of expression and purification, they are ideal for biophysical studies of GPCRs in their fully active state. The first mini-G protein developed was mini-Gs. Here we extend the family of mini-G proteins to include mini-Golf, mini-Gi1, mini-Go1 and the chimeras mini-Gs/q and mini-Gs/i. The mini-G proteins were shown to couple to relevant GPCRs and to form stable complexes with purified receptors that could be purified by size exclusion chromatography. Agonist-bound GPCRs coupled to a mini-G protein showed higher thermal stability compared to the agonist-bound receptor alone. Fusion of GFP at the N-terminus of mini-G proteins allowed receptor coupling to be monitored by fluorescence-detection size exclusion chromatography (FSEC) and, in a separate assay, the affinity of mini-G protein binding to detergent-solubilised receptors was determined. This work provides the foundation for the development of any mini-G protein and, ultimately, for the structure determination of GPCRs in a fully active state.
Mini G protein probes for active G protein–coupled receptors (GPCRs) in live cells - ScienceDirect
G protein-coupled receptor - Wikipedia
Optical approaches for single-cell and subcellular analysis of GPCR–G protein signaling
Solved RTK GPCR 80 ABD Small G protein Heterotrimeric G
Frontiers Multiple GPCR Functional Assays Based on Resonance Energy Transfer Sensors
Biosensors Monitor Ligand-Selective Effects at Kappa Opioid Receptors
GPCR screening and drug discovery: Latest trends
G-Protein coupled receptors: structure and function in drug discovery - RSC Advances (RSC Publishing) DOI:10.1039/D0RA08003A
PtdIns(4,5)P2 stabilizes active states of GPCRs and enhances selectivity of G-protein coupling
SNAP-tag® Technologies: Tools to Study Protein Function
Structural Research of G Protein-coupled Receptors (GPCRs) Class C - Creative Biostructure
Expression of mini-G proteins specifically halt cognate GPCR trafficking and intracellular signalling
14. G-Protein-Coupled Receptors – Principles of Pharmacology – Study Guide
Molecules, Free Full-Text
Classification of G proteins into four families according to their α
