Copper exposure induces trafficking of the menkes protein in intestinal epithelium of ATP7A transgenic mice.
J Nutr
; 135(12): 2762-6, 2005 Dec.
Article
em En
| MEDLINE
| ID: mdl-16317117
ABSTRACT
The final steps in the absorption and excretion of copper at the molecular level are accomplished by 2 closely related proteins that catalyze the ATP-dependent transport of copper across the plasma membrane. These proteins, ATP7A and ATP7B, are encoded by the genes affected in human genetic copper-transport disorders, namely, Menkes and Wilson diseases. We studied the effect of copper perfusion of an isolated segment of the jejunum of ATP7A transgenic mice on the intracellular distribution of ATP7A by immunofluorescence of frozen sections. Our results indicate that ATP7A is retained in the trans-Golgi network under copper-limiting conditions, but relocalized to a vesicular compartment adjacent to the basolateral membrane in intestines perfused with copper. The findings support the hypothesis that the basolateral transport of copper from the enterocyte into the portal blood may involve ATP7A pumping copper into a vesicular compartment followed by exocytosis to release the copper, rather than direct pumping of copper across the basolateral membrane.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Recombinantes de Fusão
/
Adenosina Trifosfatases
/
Cobre
/
Proteínas de Transporte de Cátions
/
Mucosa Intestinal
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Nutr
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Austrália