title: The mitochondrial ribosome-specific MrpL55 protein is essential in Drosophila and dynamically required during development.
abstract: We report on the essential Drosophila mRpL55 gene conserved exclusively in metazoans. Null mRpL55 mutants did not grow after hatching, moved slowly and died as first instar larvae. MrpL55 is similar to mammalian MRPL55, a protein that, in a large-scale mass spectrometry study, has been found as a mitoribosome-specific large subunit protein. We showed that MrpL55 was localised to the mitochondrion in S2 cells and tissues and was enriched in cells with a higher protein synthesis activity. The MrpL55 protein contains a KOW-like motif present in proteins with a role in transcriptional anti-termination and regulation of translation. Modulation of mRpL55 expression level is critical for development. Somatic clonal analysis showed that MrpL55 was not required in larval eye imaginal discs but required in pupal discs apparently during the second mitotic wave. Therefore, our results showed that the MrpL55 protein acts dynamically in the cell during development. We propose that MrpL55 is involved in Drosophila mitochondrial biogenesis and G2/M phase cell cycle progression.
authors.affiliation: Institute of Biotechnology, Developmental Biology Program, University of Helsinki, FIN-00014 Helsinki, Finland. timofei.tselykh@helsinki.fi
authors.forename: Timofey V
authors.initials: TV
authors.lastname: Tselykh
authors.forename: Christophe
authors.initials: C
authors.lastname: Roos
authors.forename: Tapio I
authors.initials: TI
authors.lastname: Heino
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D002460:Cell Line; D003001:Cloning, Molecular; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology / Q000254:growth & development* / Q000502:physiology; D005123:Eye / Q000166:cytology / Q000254:growth & development; D005260:Female; D017353:Gene Deletion; D015870:Gene Expression / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007150:Immunohistochemistry; D007814:Larva / Q000235:genetics / Q000254:growth & development; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D009348:Nematoda / Q000235:genetics; D009866:Oogenesis / Q000502:physiology; D010641:Phenotype; D017433:Protein Structure, Secondary; D023121:RNA, Messenger, Stored / Q000032:analysis / Q000502:physiology; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011995:Recombination, Genetic / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012469:Salivary Glands / Q000166:cytology / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000737:chemistry
chemical_list: D029721:Drosophila Proteins; D024101:Mitochondrial Proteins; C503865:MrpL55 protein, Drosophila; D023121:RNA, Messenger, Stored; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins