title: Multiple antibiotic resistance in Arabidopsis is conferred by mutations in a chloroplast-localized transport protein.
abstract: Widespread antibiotic resistance is a major public health concern, and plants represent an emerging antibiotic exposure route. Recent studies indicate that crop plants fertilized with antibiotic-laden animal manure accumulate antibiotics; however, the molecular mechanisms of antibiotic entry and subcellular partitioning within plant cells remain unknown. Here, we report that mutations in the Arabidopsis (Arabidopsis thaliana) locus Multiple Antibiotic Resistance1 (MAR1) confer resistance, while MAR1 overexpression causes hypersensitivity to multiple aminoglycoside antibiotics. Additionally, yeast expressing MAR1 are hypersensitive to the aminoglycoside G418. MAR1 encodes a protein with 11 putative transmembrane domains with low similarity to ferroportin1 from Danio rerio. A MAR1:yellow fluorescent protein fusion localizes to the chloroplast, and chloroplasts from plants overexpressing MAR1 accumulate more of the aminoglycoside gentamicin, while mar1-1 mutant chloroplasts accumulate less than the wild type. MAR1 overexpression lines are slightly chlorotic, and chlorosis is rescued by exogenous iron. MAR1 expression is also down-regulated by low iron. These data suggest that MAR1 is a plastid transporter that is likely to be involved in cellular iron homeostasis and allows opportunistic entry of multiple antibiotics into the chloroplast.
authors.affiliation: Section of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA. conte@mail.utexas.edu
authors.forename: Sarah
authors.initials: S
authors.lastname: Conte
authors.forename: David
authors.initials: D
authors.lastname: Stevenson
authors.forename: Ian
authors.initials: I
authors.lastname: Furner
authors.forename: Alan
authors.initials: A
authors.lastname: Lloyd
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000187:drug effects / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics*; D004492:Edetic Acid / Q000494:pharmacology; D005296:Ferrous Compounds / Q000494:pharmacology; D005839:Gentamicins / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects; D007501:Iron / Q000378:metabolism; D000090463:Iron Deficiencies; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000187:drug effects; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D030821:Plants, Genetically Modified; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D005296:Ferrous Compounds; D005839:Gentamicins; C545449:MAR1 protein, Arabidopsis; D008565:Membrane Proteins; D050505:Mutant Proteins; D011993:Recombinant Fusion Proteins; C036483:T-DNA; C055526:Fe(II)-EDTA; D004492:Edetic Acid; C010680:antibiotic G 418; D007501:Iron
references.citation: J Biol Chem. 1994 Oct 21;269(42):26092-9
references.pmid: 7929320
references.citation: EMBO J. 1999 Jun 1;18(11):3133-8
references.pmid: 10357824
references.citation: Biochim Biophys Acta. 2006 Jul;1763(7):578-94
references.pmid: 16766055
references.citation: Plant Physiol. 1999 Mar;119(3):1107-14
references.pmid: 10069850
references.citation: Chemosphere. 2006 Oct;65(5):725-59
references.pmid: 16677683
references.citation: Plant Physiol. 2008 Feb;146(2):589-601
references.pmid: 18083798
references.citation: Trends Plant Sci. 2005 Sep;10(9):450-7
references.pmid: 16085449
references.citation: Proc Natl Acad Sci U S A. 1999 Jun 8;96(12):7098-103
references.pmid: 10359845
references.citation: Plant Physiol. 2004 Feb;134(2):605-13
references.pmid: 14739345
references.citation: Proc Natl Acad Sci U S A. 1996 May 28;93(11):5624-8
references.pmid: 8643627
references.citation: Plant Physiol. 1995 May;108(1):269-275
references.pmid: 12228472
references.citation: Bioinformatics. 2007 Nov 1;23(21):2947-8
references.pmid: 17846036
references.citation: Nucleic Acids Res. 2004 Oct 26;32(19):5732-41
references.pmid: 15507686
references.citation: Antimicrob Agents Chemother. 1984 Jul;26(1):53-60
references.pmid: 6433789
references.citation: Antimicrob Agents Chemother. 2003 Apr;47(4):1371-5
references.pmid: 12654672
references.citation: J Environ Qual. 2005 Oct 12;34(6):1952-7
references.pmid: 16221813
references.citation: Plant Cell. 2002 Aug;14(8):1751-66
references.pmid: 12172020
references.citation: Plant J. 1998 Dec;16(6):735-43
references.pmid: 10069079
references.citation: Proc Natl Acad Sci U S A. 2007 Jul 3;104(27):11495-500
references.pmid: 17592141
references.citation: Biochem J. 2008 Jul 1;413(1):15-28
references.pmid: 18537794
references.citation: Protein Sci. 1999 May;8(5):978-84
references.pmid: 10338008
references.citation: Mol Genet Genomics. 2007 Jun;277(6):631-46
references.pmid: 17295027
references.citation: Proc Natl Acad Sci U S A. 2000 Oct 24;97(22):12356-60
references.pmid: 11035780
references.citation: Plant Physiol. 2007 May;144(1):197-205
references.pmid: 17351051
references.citation: J Agric Food Chem. 2006 Mar 22;54(6):2288-97
references.pmid: 16536609
references.citation: Nat Biotechnol. 2005 Sep;23(9):1177-80
references.pmid: 16116418
references.citation: Plant J. 2006 Feb;45(4):599-615
references.pmid: 16441351
references.citation: J Biol Chem. 1974 Nov 10;249(21):6806-11
references.pmid: 4609092
references.citation: Plant Cell. 2002 Jun;14(6):1223-33
references.pmid: 12084823
references.citation: J Biol Chem. 2003 Nov 28;278(48):47644-53
references.pmid: 13129917
references.citation: Plant Physiol. 2003 Jan;131(1):16-26
references.pmid: 12529511
references.citation: Biotechniques. 1992 Jul;13(1):18-20
references.pmid: 1503765
references.citation: Plant Physiol. 1992 Feb;98(2):666-72
references.pmid: 16668693
references.citation: Planta. 1970 Dec;91(4):329-35
references.pmid: 24500097
references.citation: Cell Res. 2006 Oct;16(10):830-40
references.pmid: 17031393
references.citation: Plant Mol Biol. 1999 May;40(1):37-44
references.pmid: 10394943
references.citation: Trends Plant Sci. 2005 Mar;10(3):103-5
references.pmid: 15749466
references.citation: J Mol Biol. 2003 Feb 28;326(4):1175-88
references.pmid: 12589761
references.citation: New Phytol. 2007;174(3):499-506
references.pmid: 17447906
references.citation: Plant Mol Biol. 1992 Oct;20(1):103-12
references.pmid: 1325204
references.citation: Nat Biotechnol. 2003 Apr;21(4):428-33
references.pmid: 12640467
references.citation: Anim Biotechnol. 2006;17(2):157-76
references.pmid: 17127527
references.citation: Biotechnol J. 2009 Feb;4(2):224-9
references.pmid: 19226556
references.citation: Plant Cell. 2002 Jun;14(6):1347-57
references.pmid: 12084831
references.citation: J Biol Chem. 2006 Sep 1;281(35):25532-40
references.pmid: 16790430
references.citation: J Exp Bot. 2009;60(4):1249-59
references.pmid: 19188276
references.citation: Annu Rev Plant Biol. 2003;54:183-206
references.pmid: 14509968
references.citation: Eur Arch Otorhinolaryngol. 1996;253(7):411-6
references.pmid: 8891485
references.citation: Proc Natl Acad Sci U S A. 2008 Jul 29;105(30):10619-24
references.pmid: 18647837
references.citation: Trends Plant Sci. 2002 May;7(5):193-5
references.pmid: 11992820
references.citation: Mol Gen Genet. 1994 Mar;242(6):675-80
references.pmid: 8152418
references.citation: Plant J. 2009 Feb;57(3):400-12
references.pmid: 18826427
references.citation: Curr Opin Microbiol. 2003 Oct;6(5):446-51
references.pmid: 14572535
references.citation: Yeast. 2003 Jun;20(8):739-46
references.pmid: 12794935
references.citation: New Phytol. 2008 Jul;179(2):257-285
references.pmid: 19086173
references.citation: Biochem J. 1996 Aug 15;318 ( Pt 1):67-73
references.pmid: 8761454
references.citation: Planta. 2001 Oct;213(6):967-76
references.pmid: 11722133
references.citation: J Environ Qual. 2005 Oct 12;34(6):2082-5
references.pmid: 16221828
references.citation: Biochem Pharmacol. 2000 Aug 15;60(4):457-70
references.pmid: 10874120
references.citation: Plant Cell. 2000 Apr;12(4):519-33
references.pmid: 10760241
references.citation: Planta. 2003 Feb;216(4):541-51
references.pmid: 12569395
references.citation: FEBS Lett. 2002 Oct 9;529(2-3):215-20
references.pmid: 12372603
references.citation: Plant Cell Rep. 2004 May;22(10):774-9
references.pmid: 14770263
references.citation: Biometals. 2008 Oct;21(5):503-13
references.pmid: 18322653