Characterization of a protein of the plastid inner envelope having homology to animal inorganic phosphate, chloride and organic-anion transporters.
A protein from Arabidopsis thaliana (L.) Heynh. showing homology to animal proteins of the NaPi-1 family, involved in the transport of inorganic phosphate, chloride, glutamate and sialic acid, has been characterized. This protein, named ANTR2 (for anion transporters) was shown by chloroplast subfractionation to be localized to the plastid inner envelope in both A. thaliana and Spinacia oleracea (L.). Immunolocalization revealed that ANTR2 was expressed in the leaf mesophyll cells as well as in the developing embryo at the upturned-U stage. Five additional homologues of ANTR2 are found in the Arabidopsis genome, of which one was shown by green fluorescent protein (GFP) fusion to be also located in the chloroplast. All ANTR proteins share homology to the animal NaPi-1 family, as well as to other organic-anion transporters that are members of the Anion:Cation Symporter (ACS) family, and share the main features of transporters from this family, including the presence of 12 putative transmembrane domains and of a 7-amino acid motif in the fourth putative transmembrane domain. ANTR2 thus represent a novel protein of the plastid inner envelope that is likely to be involved in anion transport.
Roth
Christian
C
Département de Biologie Moléculaire Végétale, Bâtiment de Biologie, Université de Lausanne, 1015 Lausanne, Switzerland.
Menzel
Gerhard
G
Petétot
Jean MacDonald-Comber
JM
Rochat-Hacker
Sylvie
S
Poirier
Yves
Y
D000595:Amino Acid Sequence; D000818:Animals; D027321:Anion Transport Proteins / Q000737:chemistry / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000235:genetics; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006801:Humans; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D028061:Phosphate Transport Proteins / Q000737:chemistry / Q000235:genetics*; D018087:Plastids / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D027981:Symporters / Q000737:chemistry / Q000235:genetics*; D050598:Vesicular Glutamate Transport Protein 1; D033921:Vesicular Transport Proteins; D000096922:K Cl- Cotransporters
D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D028061:Phosphate Transport Proteins; D027981:Symporters; D050598:Vesicular Glutamate Transport Protein 1; D033921:Vesicular Transport Proteins; D000096922:K Cl- Cotransporters; C493464:SLC17A7 protein, human