SLC39A9 (ZIP9) regulates zinc homeostasis in the secretory pathway: characterization of the ZIP subfamily I protein in vertebrate cells.
Biosci Biotechnol Biochem
; 73(5): 1142-8, 2009 May.
Article
en En
| MEDLINE
| ID: mdl-19420709
ABSTRACT
The SLC39A family of zinc transporters can be divided into four subfamilies (I, II, LIV-1, and gufA) in vertebrates, but studies of their functions have been restricted exclusively to members of subfamilies II and LIV-1. In this study, we characterized SLC39A9 (ZIP9), the only member of subfamily I in vertebrates. Confocal microscopy demonstrated that transiently expressed, HA-tagged human ZIP9 (hZIP9-HA) was localized to the trans-Golgi network regardless of zinc status. Disruption of the ZIP9 gene in DT40 cells did not change the growth rate, sensitivity to high zinc and manganese concentrations during long-term culture, or cellular zinc status after short-term incubation with zinc. The alkaline phosphatase activity of ZIP9(-/-) cells did not change in cells cultured in medium containing normal zinc levels. In contrast, the activity of this enzyme decreased in wild-type cells cultured in zinc deficient medium but less so in ZIP9(-/-) cells under these conditions. Stable over-expression of hZIP9-HA moderately decreased alkaline phophatase activity. These results suggest that ZIP9 functions to regulate zinc homeostasis in the secretory pathway without significantly altering cytosolic zinc homeostasis.
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Bases de datos:
MEDLINE
Asunto principal:
Zinc
/
Proteínas de Transporte de Catión
/
Vías Secretoras
/
Homeostasis
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Biosci Biotechnol Biochem
Asunto de la revista:
BIOQUIMICA
/
BIOTECNOLOGIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Japón