A role for myosin-1A in the localization of a brush border disaccharidase.
J Cell Biol
; 165(3): 395-405, 2004 May 10.
Article
em En
| MEDLINE
| ID: mdl-15138292
ABSTRACT
To gain insight regarding myosin-1A (M1A) function, we expressed a dominant negative fragment of this motor in the intestinal epithelial cell line, CACO-2BBE. Sucrase isomaltase (SI), a transmembrane disaccharidase found in microvillar lipid rafts, was missing from the brush border (BB) in cells expressing this fragment. Density gradient centrifugation, affinity purification, and immunopurification of detergent-resistant membranes isolated from CACO-2BBE cells and rat microvilli (MV) all indicate that M1A and SI reside on the same population of low density (approximately 1.12 g/ml) membranes. Chemical cross-linking of detergent-resistant membranes from rat MV indicates that SI and M1A may interact in a lipid raft complex. The functional significance of such a complex is highlighted by expression of the cytoplasmic domain of SI, which results in lower levels of M1A and a loss of SI from the BB. Together, these studies are the first to assign a specific role to M1A and suggest that this motor is involved in the retention of SI within the BB.
Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Complexo Sacarase-Isomaltase
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Proteínas de Ligação a Calmodulina
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Membrana Celular
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Mucosa Intestinal
Limite:
Animals
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Humans
Idioma:
En
Revista:
J Cell Biol
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos