Submitted to: Elsevier
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2007
Publication Date: 7/23/2007
Citation: Zhang, L., Chi, Z., Ren, H., Rong, M., Dahlstrom, A., Huang, L., Wang, Z. 2007. Imunoreactivity of zinc transporter 7 (ZNT7) in mouse dorsal root ganglia. Elsevier. Brain Research Bulletin 74 (2007) 278-283.
Interpretive Summary: In the present study, we show for the first time the residence of the ZNT7 protein, a zinc transporter protein functioning in translocation of zinc ions into a storage compartment of the cell, in the mouse dorsal root ganglion (nodules on the dorsal root of the spine that contain cell bodies of neurons). We found that neurons in the mouse dorsal root ganglion contained large amount of ZNT7 in the cell bodies. In these ZNT7-positive neuron bodies, ZNT7 was predominantly detected in the perinuclear region of the cells. Double immunofluorescence analysis suggested that ZNT7 resided in the Golgi apparatus of the cell, a compartment of the cell that processes and packages newly synthesized proteins in the cell. In addition, zinc selenium autometallography (AMG) analysis, a method detecting free zinc ions in the cell, indicated that the location of free zinc ions in the DRG overlapped with that of the ZNT7 protein. Taken together, our observation strongly suggests that ZNT7 may play an important role in facilitating zinc transport into the Golgi apparatus of the neuronal cells in the mouse DRG.
Technical Abstract: In the present study, we showed for the first time the localization of ZNT7 immunoreactivity in the mouse dorsal root ganglion (DRG) by means of immunohistochemistry and confocal laser scanning microscopy. Our results revealed that ZNT7 immunoreactivity was abundantly expressed in the nerve cells of the mouse DRG. Strong ZNT7 immunoreactivity was predominantly distributed in the perinuclear region of positive cells, while the nuclei were devoid of staining. Double immunofluorescence labeling of ZNT7 and TGN38 revealed a colocalization of the two antigens in the Golgi apparatus. In addition, the presence of labile zinc ions was detected with in vivo zinc selenium autometallography (AMG). AMG observations showed that the zinc staining pattern was also predominately located in the perinuclear Golgi area, like the ZNT7 immunostaining pattern in the DRG. These observations strongly suggest that ZNT7 may play an important role in facilitating zinc transport into the Golgi apparatus from the cytosol in the mouse DRG.