Higher plants possess two different types of ATX1-like copper chaperones.
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.
Puig
Sergi
S
Departament de Bioquímica i Biologia Molecular, Universitat de València, Av. Dr. Moliner, 50, E-46100 Burjassot, Valencia, Spain.
Mira
Helena
H
Dorcey
Eavan
E
Sancenón
Vicente
V
Andrés-Colás
Nuria
N
Garcia-Molina
Antoni
A
Burkhead
Jason L
JL
Gogolin
Kathryn A
KA
Abdel-Ghany
Salah E
SE
Thiele
Dennis J
DJ
Ecker
Joseph R
JR
Pilon
Marinus
M
Peñarrubia
Lola
L
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*
D029681:Arabidopsis Proteins; D018832:Molecular Chaperones; D014157:Transcription Factors; D003300:Copper; C504056:At2g31650 protein, Arabidopsis; D011495:Histone-Lysine N-Methyltransferase; D000251:Adenosine Triphosphatases