Copper Chaperone HAH1: The Molecular Mechanism of Action

Oregon Health & Science University, Portland OR

Investigators

Abstract

Copper is essential for normal growth and development of mammalian cells. It serves as a cofactor for numerous enzymes mediating neurotransmitter biosynthesis, radical detoxification, oxidative phosphorylation, and iron transport. Currently, little is known on how copper became incorporated into these proteins and how concentration of copper in a cell is regulated. This project addresses these fundamental questions. The research is focused on HAH1, a copper-chaperone, which delivers copper specifically to copper-transporting ATPases in mammalian cells. The long-term goal of the studies is to understand how HAH1 functions in a cell, and how its function is regulated. The experimental approach includes combination of protein biochemistry, site-directed mutagenesis, protein fragment complementation assay in cultured cell lines, and chemical labeling. These techniques are utilized (i) to determine the oligomerization state of intracellular HAH1 in the presence of different copper concentrations, (ii) to characterize copper occupancy of HAH1 within the cell, and (iii) to determine whether the in vivo interactions between HAH1 and the copper-transporting ATPase are regulated by changes in copper concentration. The results of these experiments will generate new information regarding key copper transporters in mammalian cells and will advance understanding of basic mechanisms regulating intracellular copper distribution.