| First Author | Palmiter RD | Year | 1996 |
| Journal | EMBO J | Volume | 15 |
| Issue | 8 | Pages | 1784-91 |
| PubMed ID | 8617223 | Mgi Jnum | J:32792 |
| Mgi Id | MGI:80277 | Citation | Palmiter RD, et al. (1996) ZnT-2, a mammalian protein that confers resistance to zinc by facilitating vesicular sequestration. EMBO J 15(8):1784-91 |
| abstractText | A cDNA encoding a second zinc transporter (ZnT-2) was isolated from a rat kidney cDNA expression library by complementation of a zinc-sensitive BHK cell line. The protein predicted from the open reading frame of ZnT-2 cDNA has 359 amino acids and initiates with a CTG codon. It resembles ZnT-1 (a plasma membrane protein that stimulates zinc efflux) in overall topology in that it has six membrane-spanning domains, a histidine-rich intracellular loop and a long C-terminal tail; however, the overall amino acid identity is only 26%. Unlike ZnT-1, which is in the plasma membrane and lowers cellular zinc by stimulating zinc efflux, ZnT-2 is localized on vesicles and allows the zinc-sensitive BHK cells to accumulate zinc to levels that are much higher than non-transformed cells can tolerate. Zinc was visualized within these vesicles with zinquin, a zinc-specific fluorescent probe. The intracellular compartment that accumulates zinc is acidic as revealed by staining with acridine orange or LysoTracker. Prolonged exposure of cells expressing ZnT-2 to zinc causes an accretion of intracellular vesicles. We suggest that ZnT-2 protects these cells from zinc toxicity by facilitating zinc transport into an endosomal/lysosomal compartment. |
