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Membrane orientation of G?(i)?(1)?(2) and G?(1)?(2) determined via combined vibrational spectroscopic studies.

ABSTRACT: The manner in which the heterotrimeric G protein complexes G?1?2 and G?i?1?2 interact with membranes is likely related to their biological function. We combined complementary measurements from sum frequency generation (SFG) vibrational and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine the possible membrane orientations of G?1?2 and the G?i?1?2 heterotrimer more precisely than could be achieved using SFG alone. The most likely orientations of G?1?2 and the G?i?1?2 heterotrimer were both determined to fall within a similar narrow range of twist and tilt angles, suggesting that G?1?2 may bind to G?i without a significant change in orientation. This "basal" orientation seems to depend primarily on the geranylgeranylated C-terminus of G?2 along with basic residues at the N-terminus of G?i, and suggests that activated G protein-coupled receptors (GPCRs) must reorient G protein heterotrimers at lipid bilayers to catalyze nucleotide exchange. The innovative methodologies developed in this paper can be widely applied to study the membrane orientation of other proteins in situ.

SUBMITTER: Yang P

PROVIDER: S-EPMC3731408 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

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Membrane orientation of Gα(i)β(1)γ(2) and Gβ(1)γ(2) determined via combined vibrational spectroscopic studies.

Yang Pei P Boughton Andrew A Homan Kristoff T KT Tesmer John J G JJ Chen Zhan Z

Journal of the American Chemical Society 20130321 13

The manner in which the heterotrimeric G protein complexes Gβ1γ2 and Gαiβ1γ2 interact with membranes is likely related to their biological function. We combined complementary measurements from sum frequency generation (SFG) vibrational and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine the possible membrane orientations of Gβ1γ2 and the Gαiβ1γ2 heterotrimer more precisely than could be achieved using SFG alone. The most likely orientations of Gβ1γ2 a ...[more]

PMID: 23461393

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Dataset Information

Membrane orientation of G?(i)?(1)?(2) and G?(1)?(2) determined via combined vibrational spectroscopic studies.

Publications

Membrane orientation of Gα(i)β(1)γ(2) and Gβ(1)γ(2) determined via combined vibrational spectroscopic studies.

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