Structure of an mdr-like gene from Arabidopsis thaliana. Evolutionary implications.
Multidrug resistance of mammalian tumor cells is caused by the enhanced expression of P-glycoproteins. These proteins are encoded by mdr genes and mediate the energy-dependent efflux of a variety of lipophilic drugs from cells. To test whether in plants mdr-like genes might be involved in certain cases of cross-resistance to different herbicides, we have cloned and characterized a gene from Arabidopsis thaliana, atpgp1, encoding a putative P-glycoprotein homologue. Like the mammalian P-glycoproteins, with which it shares extensive sequence homology and a similar organization in structural domains, this protein is internally duplicated. Seven of the nine introns in the atpgp1 gene match introns in the mammalian mdr genes to within a few nucleotides, and the positions of these suggest that P-glycoprotein genes evolved by duplication and subsequent fusion of an intron-containing primordial gene prior to the evolutionary separation of plants and mammals. The atpgp1 gene gives rise to transcripts present in all plant parts but particularly abundant in inflorescence axes.
Institute of Plant Biology, University of Zurich, Switzerland.
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Dudler
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Hertig
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004351:Drug Resistance / Q000235:genetics*; D015723:Gene Library; D006801:Humans; D007438:Introns; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010944:Plants / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins; D009838:Oligodeoxyribonucleotides; D012313:RNA; D004247:DNA