title: AtAzg1 and AtAzg2 comprise a novel family of purine transporters in Arabidopsis.
abstract: In plants, nucleobase biochemistry is highly compartmented relying upon a well-regulated and selective membrane transport system. In Arabidopsis two proteins, AtAzg1 and AtAzg2, show substantial amino acid sequence similarity to the adenine-guanine-hypoxanthine transporter AzgA of Aspergillus nidulans. Analysis of single and double mutant lines harboring T-DNA insertion alleles AtAzg1-1 and AtAzg2-1 reveal a marked resistance to growth in the presence of 8-azaadenine and 8-azaguanine but not to other toxic nucleobase analogues. Conversely, yeast strains expressing AtAzg1 and AtAzg2 gain heightened sensitivity to growth on 8-azaadenine and 8-azaguanine. Radio-labeled purine uptake experiments in yeast and in planta confirm the function of AtAzg1 and AtAzg2 as plant adenine-guanine transporters.
authors.affiliation: Department of Biology, Indiana University-Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Mansfield
authors.forename: Neil P
authors.initials: NP
authors.lastname: Schultes
authors.forename: George S
authors.initials: GS
authors.lastname: Mourad
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000378:metabolism*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D001375:Azaguanine / Q000378:metabolism; D001692:Biological Transport; D006147:Guanine / Q000378:metabolism*; D008969:Molecular Sequence Data; D033702:Nucleobase Transport Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D033702:Nucleobase Transport Proteins; D006147:Guanine; D000225:Adenine; D001375:Azaguanine; C006654:8-azaadenine