Nanoscale analysis reveals no domain formation of glycosylphosphatidylinositol-anchored protein SAG1 in the plasma membrane of living Toxoplasma gondii.
Histochem Cell Biol
; 152(5): 365-375, 2019 Nov.
Article
en En
| MEDLINE
| ID: mdl-31542792
ABSTRACT
Glycosylphosphatidylinositol (GPI)-anchored proteins typically localise to lipid rafts. GPI-anchored protein microdomains may be present in the plasma membrane; however, they have been studied using heterogeneously expressed GPI-anchored proteins, and the two-dimensional distributions of endogenous molecules in the plasma membrane are difficult to determine at the nanometre scale. Here, we used immunoelectron microscopy using a quick-freezing and freeze-fracture labelling (QF-FRL) method to examine the distribution of the endogenous GPI-anchored protein SAG1 in Toxoplasma gondii at the nanoscale. QF-FRL physically immobilised molecules in situ, minimising the possibility of artefactual perturbation. SAG1 labelling was observed in the exoplasmic, but not cytoplasmic, leaflets of T. gondii plasma membrane, whereas none was detected in any leaflet of the inner membrane complex. Point pattern analysis of SAG1 immunogold labelling revealed mostly random distribution in T. gondii plasma membrane. The present method obtains information on the molecular distribution of natively expressed GPI-anchored proteins and demonstrates that SAG1 in T. gondii does not form significant microdomains in the plasma membrane.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Toxoplasma
/
Proteínas Protozoarias
/
Membrana Celular
/
Glicosilfosfatidilinositoles
/
Antígenos de Protozoos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Histochem Cell Biol
Asunto de la revista:
CITOLOGIA
/
HISTOCITOQUIMICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Japón