Regulation of GTPase function by autophosphorylation.
Mol Cell
; 82(5): 950-968.e14, 2022 03 03.
Article
em En
| MEDLINE
| ID: mdl-35202574
ABSTRACT
A unifying feature of the RAS superfamily is a conserved GTPase cycle by which these proteins transition between active and inactive states. We demonstrate that autophosphorylation of some GTPases is an intrinsic regulatory mechanism that reduces nucleotide hydrolysis and enhances nucleotide exchange, altering the on/off switch that forms the basis for their signaling functions. Using X-ray crystallography, nuclear magnetic resonance spectroscopy, binding assays, and molecular dynamics on autophosphorylated mutants of H-RAS and K-RAS, we show that phosphoryl transfer from GTP requires dynamic movement of the switch II region and that autophosphorylation promotes nucleotide exchange by opening the active site and extracting the stabilizing Mg2+. Finally, we demonstrate that autophosphorylated K-RAS exhibits altered effector interactions, including a reduced affinity for RAF proteins in mammalian cells. Thus, autophosphorylation leads to altered active site dynamics and effector interaction properties, creating a pool of GTPases that are functionally distinct from their non-phosphorylated counterparts.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
GTP Fosfo-Hidrolases
Limite:
Animals
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos