Characterization of the Menkes protein copper-binding domains and their role in copper-induced protein relocalization

Hum Mol Genet. 1999 Aug;8(8):1473-8. doi: 10.1093/hmg/8.8.1473.

Abstract

Menkes disease is a fatal X-linked disorder of copper metabolism. The gene defective in Menkes disease (ATP7A) encodes a copper transporting P-type ATPase (MNK or ATP7A) with six copper-binding domains at its N-terminus. MNK is normally localized to the trans -Golgi network in cultured cells, but relocates to the plasma membrane in the presence of elevated extracellular copper. In this study, the role of the six copper-binding domains on copper-induced redistribution is investigated. In a recombinant clone, when all the wild-type copper-binding motifs are mutated from GMXCXXC to GMXSXXS and the cells grown in medium containing elevated copper, relocalization of the recombinant protein to the plasma membrane was not observed. Using the same assay with any one of the six copper-binding domains intact, MNK moves to the plasma membrane in a way indistinguishable from the wild-type protein. Therefore, the copper-binding domains are vital for MNK trafficking and only a single domain is sufficient for this redistribution to occur.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics*
  • Adenosine Triphosphatases / metabolism
  • Binding Sites / genetics
  • Binding Sites / physiology
  • Biological Transport / drug effects
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cation Transport Proteins*
  • Cell Line
  • Copper / pharmacology
  • Copper-Transporting ATPases
  • Humans
  • Menkes Kinky Hair Syndrome / genetics*
  • Mutation
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism

Substances

  • Carrier Proteins
  • Cation Transport Proteins
  • Recombinant Fusion Proteins
  • copper-binding protein
  • Copper
  • Adenosine Triphosphatases
  • ATP7A protein, human
  • Copper-Transporting ATPases