Constitutive expression of hZnT4 zinc transporter in human breast epithelial cells

Michalczyk, Agnes, Allen, Justin, Blomeley, Rachael and Ackland, Leigh 2002, Constitutive expression of hZnT4 zinc transporter in human breast epithelial cells, Biochemical journal, vol. 364, pp. 105-113.

Attached Files
Name Description MIMEType Size Downloads

Title Constitutive expression of hZnT4 zinc transporter in human breast epithelial cells
Author(s) Michalczyk, AgnesORCID iD for Michalczyk, Agnes
Allen, Justin
Blomeley, Rachael
Ackland, LeighORCID iD for Ackland, Leigh
Journal name Biochemical journal
Volume number 364
Start page 105
End page 113
Publisher Portland Press
Place of publication London, England
Publication date 2002-05-15
ISSN 0264-6021
Keyword(s) epithelial cells
zinc gene
zinc transport
Summary Zinc is an essential trace element required by all living organisms. An adequate supply of zinc is particularly important in the neonatal period. Zinc is a significant component of breast milk, which is transported across the maternal epithelia during lactation. The mechanisms by which zinc becomes a constituent of breast milk have not been elucidated. The function of the zinc transporter ZnT4 in the transport of zinc into milk during lactation was previously demonstrated by studies of a mouse mutant, the ‘lethal milk’ mouse, where a mutation in the ZnT4 gene decreased the transport of zinc into milk. In the present study, we have investigated the expression of the human orthologue of ZnT4 (hZnT4) in the human breast. We detected hZnT4 mRNA expression in the tissue from the resting and lactating human breast, using reverse-transcriptase PCR. Western-blot analysis using antibodies to peptide sequences of hZnT4 detected a major band of the predicted size of 47 kDa and a minor band of 77 kDa, in extracts from the resting and lactating breast tissues. There was no difference in the hZnT4 expression levels between lactating and resting breasts. The hZnT4 protein was present in the luminal cells of the ducts and alveoli where it had a granular distribution. A cultured human breast epithelial cell line PMC42 was used to investigate the subcellular distribution of hZnT4 and this showed a granular label throughout the cytoplasm, consistent with a vesicular localization. The presence of zinc-containing intracellular vesicles was demonstrated by using the zinc-specific fluorphore Zinquin (ethyl-[2-methyl-8-p-toluenesulphonamido-6-quinolyloxy]acetate). Double labelling indicated that there was no obvious overlap between Zinquin and the hZnT4 protein, suggesting that hZnT4 was not directly involved in the transport of zinc into vesicles. We detected expression of two other members of the hZnT family, hZnT1 and hZnT3, in human breast epithelial cells. We conclude that hZnT4 is constitutively expressed in the human breast and may be one of the several members of the ZnT family involved in the transport of zinc into milk.
Language eng
Field of Research 060199 Biochemistry and Cell Biology not elsewhere classified
Socio Economic Objective 970106 Expanding Knowledge in the Biological Sciences
HERDC Research category C1 Refereed article in a scholarly journal
Copyright notice ©2002, Biochemical Society
Persistent URL

Connect to link resolver
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 58 times in TR Web of Science
Scopus Citation Count Cited 63 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 967 Abstract Views, 0 File Downloads  -  Detailed Statistics
Created: Mon, 07 Jul 2008, 08:05:13 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact