Structural basis and mechanism of activation of two different families of G proteins by the same GPCR.
Nat Struct Mol Biol
; 28(11): 936-944, 2021 11.
Article
in En
| MEDLINE
| ID: mdl-34759376
ABSTRACT
The ß1-adrenergic receptor (ß1-AR) can activate two families of G proteins. When coupled to Gs, ß1-AR increases cardiac output, and coupling to Gi leads to decreased responsiveness in myocardial infarction. By comparative structural analysis of turkey ß1-AR complexed with either Gi or Gs, we investigate how a single G-protein-coupled receptor simultaneously signals through two G proteins. We find that, although the critical receptor-interacting C-terminal α5-helices on Gαi and Gαs interact similarly with ß1-AR, the overall interacting modes between ß1-AR and G proteins vary substantially. Functional studies reveal the importance of the differing interactions and provide evidence that the activation efficacy of G proteins by ß1-AR is determined by the entire three-dimensional interaction surface, including intracellular loops 2 and 4 (ICL2 and ICL4).
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Structure, Tertiary
/
Receptors, Adrenergic, beta-1
/
GTP-Binding Protein alpha Subunits, Gi-Go
/
GTP-Binding Protein alpha Subunits, Gs
Limits:
Animals
/
Humans
Language:
En
Journal:
Nat Struct Mol Biol
Journal subject:
BIOLOGIA MOLECULAR
Year:
2021
Type:
Article
Affiliation country:
United States