title: Localization of riboproteins in a trypanosomatid mitochondrion.
abstract: There is growing evidence in support of mitochondrial translation in trypanosomes but mitoribosomes have never been characterized or localized in these parasites. On RNA-protein blots we identified several proteins from the trypanosomatid Crithidia fasciculata which bound the parasite's 12S and 9S mitochondrial ribosomal RNAs. Two of these proteins had significant amino acid sequence homology to riboproteins S8 and S21 across phyla. Immunoelectron microscopy revealed that antibodies raised against the two proteins react with matrix components in the C. fasciculata mitochondrion. Our data thus provide, we believe for the first time, evidence for the presence of riboproteins within a trypanosomatid mitochondrion, bound, possibly, to the 12S and 9S RNAs. The proteins were immunologically related to two cytosolic riboproteins which were also of identical size, suggesting the interesting possibility that the same set of riboproteins is shared between the cytosol and the mitochondrion in this parasite.
authors.affiliation: Department of Cell and Molecular Biology, University of Umeå, S-901 87, Umeå, Sweden. ivor.tittawella@cmb.umu.se
authors.forename: I
authors.initials: I
authors.lastname: Tittawella
authors.forename: V
authors.initials: V
authors.lastname: Baranov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D016831:Crithidia fasciculata / Q000166:cytology* / Q000378:metabolism*; D003429:Cross Reactions / Q000276:immunology; D003593:Cytoplasm / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016253:Microscopy, Immunoelectron; D008928:Mitochondria / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008970:Molecular Weight; D014176:Protein Biosynthesis; D015800:Protozoan Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D016053:RNA, Protozoan / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D000906:Antibodies; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C032643:ribosomal protein S21; C030254:ribosomal protein S8