Expression of the human menkes ATPase in Xenopus laevis oocytes

Menkes disease is an X-linked disorder of copper metabolism that is usually fatal. The affected gene has recently been cloned and encodes one of the t wo human copper ATPases. If the Menkes ATPase is defective, copper is trapp ed in the intestinal mucosa, leading to systemic copper deficiency. In orde r to study copper transport by this ATPase and the effects of disease mutat ions on its function, we developed a Xenopus laevis oocyte expression syste m. Wild-type Menkes ATPase cDNA and a fusion of this gene with the green fl uorescent protein (GFP) gene was transcribed in vitro and the mRNA injected into oocytes. Expression in oocytes was analyzed by Western blotting and f luorescence microscopy. The Menkes ATPase-GFP chimera appeared to localize primarily to the plasma membrane as assessed by confocal microscopy. This s ystem should thus provide an interesting new tool to study the function of the Menkes ATPase.