title: Higher plants possess two different types of ATX1-like copper chaperones.
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.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Universitat de València, Av. Dr. Moliner, 50, E-46100 Burjassot, Valencia, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Puig
authors.forename: Helena
authors.initials: H
authors.lastname: Mira
authors.forename: Eavan
authors.initials: E
authors.lastname: Dorcey
authors.forename: Vicente
authors.initials: V
authors.lastname: Sancenón
authors.forename: Nuria
authors.initials: N
authors.lastname: Andrés-Colás
authors.forename: Antoni
authors.initials: A
authors.lastname: Garcia-Molina
authors.forename: Jason L
authors.initials: JL
authors.lastname: Burkhead
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Gogolin
authors.forename: Salah E
authors.initials: SE
authors.lastname: Abdel-Ghany
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Thiele
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Ecker
authors.forename: Marinus
authors.initials: M
authors.lastname: Pilon
authors.forename: Lola
authors.initials: L
authors.lastname: Peñarrubia
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D017360:Arabidopsis / Q000737:chemistry* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D018745:Genome, Plant / Q000502:physiology; D011495:Histone-Lysine N-Methyltransferase; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D018832:Molecular Chaperones; D014157:Transcription Factors; D003300:Copper; C504056:At2g31650 protein, Arabidopsis; D011495:Histone-Lysine N-Methyltransferase; D000251:Adenosine Triphosphatases