VAMP4 cycles from the cell surface to the trans-Golgi network via sorting and recycling endosomes.
J Cell Sci
; 120(Pt 6): 1028-41, 2007 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-17327277
ABSTRACT
VAMP4 is enriched in the trans-Golgi network (TGN) and functions in traffic from the early and recycling endosomes to the TGN, but its trafficking itinerary is unknown. Cells stably expressing TGN-enriched VAMP4 C-terminally-tagged with EGFP (VAMP4-EGFP) are able to internalize and transport EGFP antibody efficiently to the TGN, suggesting that VAMP4-EGFP cycles between the cell surface and the TGN. The N-terminal extension of VAMP4 endows a chimeric VAMP5 with the ability to cycle from the surface to the TGN. Detailed time-course analysis of EGFP antibody transport to the TGN as well as pharmacological and thermal perturbation experiments suggest that VAMP4-EGFP is endocytosed by clathrin-dependent pathways and is delivered to the sorting and then recycling endosomes. This is followed by a direct transport to the TGN, without going through the late endosome. The di-Leu motif of the TGN-targeting signal is important for internalization, whereas the acidic cluster is crucial for efficient delivery of internalized antibody from the endosome to the TGN. These results suggest that the TGN-targeting signal of VAMP4 mediates the efficient recycling of VAMP4 from the cell surface to the TGN via the sorting and recycling endosomes, thus conferring steady-state enrichment of VAMP4 at the TGN.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Endossomos
/
Sinais Direcionadores de Proteínas
/
Membrana Celular
/
Proteínas R-SNARE
/
Complexo de Golgi
Limite:
Animals
Idioma:
En
Revista:
J Cell Sci
Ano de publicação:
2007
Tipo de documento:
Article