Conformational dynamics of a G-protein α subunit is tightly regulated by nucleotide binding.
Proc. Natl. Acad. Sci. U.S.A. 113, E3629-E3638 (2016)
Heterotrimeric G proteins play a pivotal role in the signal-transduction pathways initiated by G-protein-coupled receptor (GPCR) activation. Agonist-receptor binding causes GDP-to-GTP exchange and dissociation of the Gα subunit from the heterotrimeric G protein, leading to downstream signaling. Here, we studied the internal mobility of a G-protein α subunit in its apo and nucleotide-bound forms and characterized their dynamical features at multiple time scales using solution NMR, small-angle X-ray scattering, and molecular dynamics simulations. We find that binding of GTP analogs leads to a rigid and closed arrangement of the Gα subdomain, whereas the apo and GDP-bound forms are considerably more open and dynamic. Furthermore, we were able to detect two conformational states of the Gα Ras domain in slow exchange whose populations are regulated by binding to nucleotides and a GPCR. One of these conformational states, the open state, binds to the GPCR; the second conformation, the closed state, shows no interaction with the receptor. Binding to the GPCR stabilizes the open state. This study provides an in-depth analysis of the conformational landscape and the switching function of a G-protein α subunit and the influence of a GPCR in that landscape.
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
Gpcr ; Nmr ; Saxs ; Signaling ; Structure; Heterotrimeric G-protein; Phospholipid-bilayer Nanodiscs; Crystal-structure; Relaxation Dispersion; Molecular-dynamics; Directed Evolution; Escherichia-coli; Coupled Receptor; Nmr Data; Activation
Keywords plus
Sprache
englisch
Veröffentlichungsjahr
2016
Prepublished im Jahr
HGF-Berichtsjahr
2016
ISSN (print) / ISBN
0027-8424
e-ISSN
1091-6490
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 113,
Heft: 26,
Seiten: E3629-E3638
Artikelnummer: ,
Supplement: ,
Reihe
Verlag
National Academy of Sciences
Verlagsort
Washington
Tag d. mündl. Prüfung
0000-00-00
Betreuer
Gutachter
Prüfer
Topic
Hochschule
Hochschulort
Fakultät
Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
30505 - New Technologies for Biomedical Discoveries
30203 - Molecular Targets and Therapies
Forschungsfeld(er)
Enabling and Novel Technologies
PSP-Element(e)
G-553600-001
G-503000-001
Förderungen
Copyright
Erfassungsdatum
2016-06-27