Sorting of GPI-anchored proteins into ER exit sites by p24 proteins is dependent on remodeled GPI.
J Cell Biol
; 194(1): 61-75, 2011 Jul 11.
Article
en En
| MEDLINE
| ID: mdl-21727194
ABSTRACT
Glycosylphosphatidylinositol (GPI) anchoring of proteins is a posttranslational modification occurring in the endoplasmic reticulum (ER). After GPI attachment, proteins are transported by coat protein complex II (COPII)-coated vesicles from the ER. Because GPI-anchored proteins (GPI-APs) are localized in the lumen, they cannot interact with cytosolic COPII components directly. Receptors that link GPI-APs to COPII are thought to be involved in efficient packaging of GPI-APs into vesicles; however, mechanisms of GPI-AP sorting are not well understood. Here we describe two remodeling reactions for GPI anchors, mediated by PGAP1 and PGAP5, which were required for sorting of GPI-APs to ER exit sites. The p24 family of proteins recognized the remodeled GPI-APs and sorted them into COPII vesicles. Association of p24 proteins with GPI-APs was pH dependent, which suggests that they bind in the ER and dissociate in post-ER acidic compartments. Our results indicate that p24 complexes act as cargo receptors for correctly remodeled GPI-APs to be sorted into COPII vesicles.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Glicosilfosfatidilinositoles
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Proteínas de Transporte Vesicular
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Retículo Endoplásmico
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Proteínas Ligadas a GPI
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Modelos Biológicos
Límite:
Animals
Idioma:
En
Revista:
J Cell Biol
Año:
2011
Tipo del documento:
Article
País de afiliación:
Japón