Higher plants possess two different types of ATX1-like copper chaperones

Biochem Biophys Res Commun. 2007 Mar 9;354(2):385-90. doi: 10.1016/j.bbrc.2006.12.215. Epub 2007 Jan 9.

Abstract

Copper (Cu) chaperones constitute a family of small Cu+-binding proteins required for Cu homeostasis in eukaryotes. The ATX1 family of Cu chaperones specifically delivers Cu to heavy metal P-type ATPases. The plant Arabidopsis thaliana expresses the ATX1-like Cu chaperone CCH, which exhibits a plant-specific carboxy-terminal domain (CTD) with unique structural properties. We show that CCH homologues from other higher plants contain CTDs with structural properties similar to Arabidopsis CCH. Furthermore, we identify a new ATX1-like Cu chaperone in Arabidopsis, AtATX1, which functionally complements yeast atx1Delta and sod1Delta associated phenotypes, and localizes to the cytosol of Arabidopsis cells. Interestingly, AtATX1, but not full-length CCH, interacts in vivo with the Arabidopsis RAN1 Cu-transporting P-type ATPase by yeast two-hybrid. We propose that higher plants express two types of ATX1-like Cu chaperones: the ATX1-type with a predominant function in Cu delivery to P-type ATPases, and the CCH-type with additional CTD-mediated plant-specific functions.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Arabidopsis / chemistry*
  • Arabidopsis / genetics
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology*
  • Copper / chemistry
  • Copper / metabolism*
  • Genome, Plant / physiology
  • Molecular Chaperones / chemistry
  • Molecular Chaperones / genetics
  • Molecular Chaperones / physiology*
  • Protein Structure, Tertiary
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / physiology*

Substances

  • Arabidopsis Proteins
  • Molecular Chaperones
  • Transcription Factors
  • Copper
  • At2g31650 protein, Arabidopsis
  • Adenosine Triphosphatases