Signal-dependent export of GABA transporter 1 from the ER-Golgi intermediate compartment is specified by a C-terminal motif.
J Cell Sci
; 121(Pt 6): 753-61, 2008 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-18285449
ABSTRACT
The C-terminus of GABA transporter 1 (GAT1, SLC6A1) is required for trafficking of the protein through the secretory pathway to reach its final destination, i.e. the rim of the synaptic specialization. We identified a motif of three hydrophobic residues (569VMI571) that was required for export of GAT1 from the ER-Golgi intermediate compartment (ERGIC). This conclusion was based on the following observations (i) GAT1-SSS, the mutant in which 569VMI571 was replaced by serine residues, was exported from the ER in a COPII-dependent manner but accumulated in punctate structures and failed to reach the Golgi; (ii) under appropriate conditions (imposing a block at 15 degrees C, disruption of COPI), these structures also contained ERGIC53; (iii) the punctae were part of a dynamic compartment, because it was accessible to a second anterograde cargo [the temperature-sensitive variant of vesicular stomatitis virus G protein (VSV-G)] and because GAT1-SSS could be retrieved from the punctate structures by addition of a KKxx-based retrieval motif, which supported retrograde transport to the ER. To the best of our knowledge, the VMI-motif of GAT1 provides the first example of a cargo-based motif that specifies export from the ERGIC.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Retículo Endoplasmático
/
Proteínas da Membrana Plasmática de Transporte de GABA
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Cell Sci
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Áustria