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Updated: Aug 21, 2026

Strategic Screening and Characterization of the Visual GPCR-mini-G Protein Signaling Complex for Successful Crystallization
Published on: March 16, 2020
Biochemical purification and functional analysis of complexes between the G-protein subunit Gbeta5 and RGS proteins
D Scott Witherow1, Vladlen Z Slepak
1Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.
Abstract:
Regulator of G-protein signaling (RGS) proteins of the R7 subfamily (RGS6, 7, 9, and 11) contain a unique Ggamma-like (GGL) domain that enables their association with the G-protein beta subunit Gbeta5. The existence of these complexes was demonstrated by their purification from native tissues as well as by reconstitution in vitro. According to pulse-chase analysis, Gbeta5 and RGS7 monomers undergo rapid proteolytic degradation in cells, whereas the dimer is stable. Studies of the functional role of Gbeta5-RGS dimers using GTPase activity, ion channel, and calcium mobilization assays showed that, similarly to other RGS proteins, they can negatively regulate G-protein-mediated signal transduction. Protein-protein interactions involving the Gbeta5-RGS7 complex can be studied in cells using fluorescence resonance energy transfer utilizing Gbeta5, RGS, and Galpha subunits fused to the cyan and yellow versions of green fluorescent protein.
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