Multimerization and Retention of the Scavenger Receptor SR-B1 in the Plasma Membrane.
Dev Cell
; 50(3): 283-295.e5, 2019 08 05.
Article
en En
| MEDLINE
| ID: mdl-31231038
ABSTRACT
Scavenger receptor B1 (SR-B1), the main receptor for high-density lipoprotein (HDL), is key in preventing atherosclerosis. It removes cholesterol from HDL, returning the lipid-poor lipoprotein to the circulation. To study the mechanisms controlling SR-B1 dynamics at the plasma membrane and its internalization rate, we developed a single-chain variable fragment (ScFv) antibody to image the receptor in live cells and track the behavior of single SR-B1 molecules. Unlike transferrin receptors, cholera-toxin-binding gangliosides, and bulk membrane markers, SR-B1 was internalized only marginally over hours. Plasmalemmal retention was not attributable to its C-terminal PDZ-binding domain or to attachment to the cortical cytoskeleton. Instead, SR-B1 undergoes multimerization into large metastable clusters that, despite being mobile in the membrane, fail to enter endocytic pathways. SR-B1 multimerization was impaired by mutating its C-terminal leucine zipper and by disrupting actin polymerization, causing rapid receptor internalization. Multimerization and plasmalemmal retention are critical for SR-B1 function.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Membrana Celular
/
Receptores Depuradores de Clase B
/
Multimerización de Proteína
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Dev Cell
Asunto de la revista:
EMBRIOLOGIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Canadá