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Ric-8A, a G protein chaperone with nucleotide exchange activity induces long-range secondary structure changes in Gα
- Source :
- eLife, eLife, Vol 5 (2016)
- Publication Year :
- 2016
- Publisher :
- eLife Sciences Publications, Ltd, 2016.
-
Abstract
- Cytosolic Ric-8A has guanine nucleotide exchange factor (GEF) activity and is a chaperone for several classes of heterotrimeric G protein α subunits in vertebrates. Using Hydrogen-Deuterium Exchange-Mass Spectrometry (HDX-MS) we show that Ric-8A disrupts the secondary structure of the Gα Ras-like domain that girds the guanine nucleotide-binding site, and destabilizes the interface between the Gαi1 Ras and helical domains, allowing domain separation and nucleotide release. These changes are largely reversed upon binding GTP and dissociation of Ric-8A. HDX-MS identifies a potential Gα interaction site in Ric-8A. Alanine scanning reveals residues crucial for GEF activity within that sequence. HDX confirms that, like G protein-coupled receptors (GPCRs), Ric-8A binds the C-terminus of Gα. In contrast to GPCRs, Ric-8A interacts with Switches I and II of Gα and possibly at the Gα domain interface. These extensive interactions provide both allosteric and direct catalysis of GDP unbinding and release and GTP binding. DOI: http://dx.doi.org/10.7554/eLife.19238.001
- Subjects :
- 0301 basic medicine
GTP'
QH301-705.5
G protein
Protein Conformation
Science
GTP-Binding Protein alpha Subunits
non-receptor guanine nucleotide exchange factor
Biochemistry
Guanosine Diphosphate
General Biochemistry, Genetics and Molecular Biology
Mass Spectrometry
03 medical and health sciences
Protein structure
Heterotrimeric G protein
hemic and lymphatic diseases
Animals
Guanine Nucleotide Exchange Factors
Biology (General)
G protein-coupled receptor
030102 biochemistry & molecular biology
General Immunology and Microbiology
Chemistry
General Neuroscience
heterotrimeric G proteins
Nuclear Proteins
General Medicine
Biophysics and Structural Biology
Rats
G beta-gamma complex
030104 developmental biology
protein dynamics
Biophysics
ras Proteins
Medicine
Rat
Guanine nucleotide exchange factor
protein secondary structure
Guanosine Triphosphate
hydrogen-deuterium exchange mass spectrometry
Research Article
Molecular Chaperones
Subjects
Details
- Language :
- English
- ISSN :
- 2050084X
- Volume :
- 5
- Database :
- OpenAIRE
- Journal :
- eLife
- Accession number :
- edsair.doi.dedup.....55f30f8c640bfcda974f94bd006f1aff