Identification of a copper transporter family in Arabidopsis thaliana.
Despite copper ions being crucial in proteins participating in plant processes such as electron transport, free-radical elimination and hormone perception and signaling, very little is known about copper inward transport across plant membranes. In this work, a five-member family (COPT1-5) of putative Arabidopsis copper transporters is described. We ascertain the ability of these proteins to functionally complement and transport copper in the corresponding Saccharomyces cerevisiae high-affinity copper transport mutant. The specific expression pattern of the Arabidopsis COPT1-5 mRNA in different tissues was analyzed by RT-PCR. Although all members are ubiquitously expressed, differences in their relative abundance in roots, leaves, stem and flowers have been observed. Moreover, steady-state COPT1 and COPT2 mRNA levels, the members that are most efficacious in complementing the S. cerevisiae high-affinity copper transport mutant, are down-regulated under copper excess, consistent with a role for these proteins in copper transport in Arabidopsis cells.
Sancenón
Vicente
V
Departament de Bioquímica i Biologia Molecular, Universitat de València, Dr. Moliner 50, Burjassot, València, 46100 Spain.
Puig
Sergi
S
Mira
Helena
H
Thiele
Dennis J
DJ
Peñarrubia
Lola
L
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D003300:Copper / Q000378:metabolism / Q000494:pharmacology; D000079923:Copper Transporter 1; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D005816:Genetic Complementation Test; D026901:Membrane Transport Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D009154:Mutation; D010802:Phylogeny; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; C097086:COPT1 protein, Arabidopsis; D000079923:Copper Transporter 1; D018076:DNA, Complementary; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D003300:Copper