Identification of a human ABCC10 orthologue in Catharanthus roseus reveals a U12-type intron determinant for the N-terminal domain feature.
ABC (ATP-binding cassette) transporters are members of a large superfamily of proteins that utilize ATP hydrolysis to translocate a wide range of substrates across biological membranes. In general, members of C subfamily (ABCC) are structurally characterized by an additional (N-terminal) transmembrane domain (TMD0). Phylogenetic analysis of plant ABCCs separates their protein sequences into three distinct clusters: I and II are plant specific whereas cluster III contains both human and plant ABCCs. Screening of the Plant Medicinal Genomics Resource database allowed us to identify 16 ABCCs partial sequences in Catharanthus roseus; two of which belong to the unique CrABCC1 transcript that we identified in cluster III. Genomic organization of CrABCC1 TMD0 coding sequence displays an AT-AC U12-type intron that is conserved in higher plant orthologues. We showed that CrABCC1, like its human orthologue ABCC10, produces alternative transcripts that encode protein sequences with a truncated form of TMD0 without the first transmembrane span (TM1). Subcellular localization of CrABCC1 TMD0 variants using yellow fluorescent protein fusions reveals that the TM1 is required for a correct routing of the TMD0 to the tonoplast. Finally, the specific repartition of CrABCC1 orthologues in some species suggests that this gene was lost several times during evolution and that its physiological function may, rely on a common feature of multicellular eukaryotes.
Taissir
T
El-Guizani
Clotilde
C
Guibert
Saida
S
Triki
Benoit
B
St-Pierre
Eric
E
Ducos
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D030008:Catharanthus / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D020224:Expressed Sequence Tags; D015870:Gene Expression; D023061:Gene Order; D056426:Genetic Loci; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D007438:Introns; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000737:chemistry / Q000235:genetics*; D005810:Multigene Family; D016366:Open Reading Frames; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D022821:RNA Splice Sites; D012326:RNA Splicing; D012342:RNA, Small Nuclear / Q000235:genetics*; D016415:Sequence Alignment
D018528:ATP-Binding Cassette Transporters; D018076:DNA, Complementary; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010940:Plant Proteins; D022821:RNA Splice Sites; D012342:RNA, Small Nuclear; C421142:ABCC10 protein, human; C096986:U12 small nuclear RNA