Deglycosylation and subcellular redistribution of VMAT2 in the mesostriatal system during normal aging.
Neurobiol Aging
; 29(11): 1702-11, 2008 Nov.
Article
en En
| MEDLINE
| ID: mdl-17582657
The vesicular monoamine transporter type 2 (VMAT2) is a transmembrane glycoprotein responsible for the vesicular monoamine uptake in the brain. This function declines in the dopaminergic mesostriatal system during normal aging, but the mechanisms responsible for this deficit are unknown. We investigated possible age-related changes in the expression and subcellular distribution of VMAT2 in the rat mesostriatal system. VMAT2 is constitutively expressed as glycosylated (75 kDa), partially glycosylated (55 kDa) and native (45 kDa) forms, they are all present in both synaptosomal compartments (synaptosomal membrane and synaptic vesicle-enriched fractions) of the striatal terminals in young rats. In aged rats, no changes were found in midbrain VMAT2mRNA and VMAT2 total protein levels in whole striatal extracts. However, its subcellular distribution and glycosylation pattern were severely modified. The three VMAT2 forms virtually disappeared from the synaptic vesicle-enriched fraction, while the 55 kDa form was accumulated in the soluble compartment. These changes may be responsible for the loss of VMAT2 activity during aging and may contribute to the high susceptibility of aged midbrain dopaminergic cells to degeneration.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fracciones Subcelulares
/
Sinapsis
/
Envejecimiento
/
Cuerpo Estriado
/
Proteínas de Transporte Vesicular de Monoaminas
Límite:
Animals
Idioma:
En
Revista:
Neurobiol Aging
Año:
2008
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Estados Unidos