New insights into P2X7 receptor regulation: Ca2+-calmodulin and GDP bind to the soluble P2X7 ballast domain.
J Biol Chem
; 298(10): 102495, 2022 10.
Article
em En
| MEDLINE
| ID: mdl-36115462
ABSTRACT
P2X7 receptors are nonselective cation channels that are activated by extracellular ATP and play important roles in inflammation. They differ from other P2X family members by a large intracellular C-terminus that mediates diverse signaling processes that are little understood. A recent cryo-EM study revealed that the C-terminus of the P2X7 receptor forms a unique cytoplasmic ballast domain that possesses a GDP-binding site as well as a dinuclear Zn2+ site. However, the molecular basis for the regulatory function of the ballast domain as well as the interplay between the various ligands remain unclear. Here, we successfully expressed a soluble trimeric P2X7 ballast domain (P2X7BD) and characterized its ligand binding properties using a biophysical approach. We identified calmodulin (CaM)-binding regions within the ballast domain and found that binding of Ca2+-CaM and GDP to P2X7BD have opposite effects on its stability. Small-angle X-ray scattering experiments indicate that Ca2+-CaM binding disrupts the trimeric state of P2X7BD. Our results provide a possible framework for the intracellular regulation of the P2X7 receptor.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Calmodulina
/
Receptores Purinérgicos P2X7
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Alemanha