title: Genomic structure and expression analysis of the RNase kappa family ortholog gene in the insect Ceratitis capitata.
abstract: Cc RNase is the founding member of the recently identified RNase kappa family, which is represented by a single ortholog in a wide range of animal taxonomic groups. Although the precise biological role of this protein is still unknown, it has been shown that the recombinant proteins isolated so far from the insect Ceratitis capitata and from human exhibit ribonucleolytic activity. In this work, we report the genomic organization and molecular evolution of the RNase kappa gene from various animal species, as well as expression analysis of the ortholog gene in C. capitata. The high degree of amino acid sequence similarity, in combination with the fact that exon sizes and intronic positions are extremely conserved among RNase kappa orthologs in 15 diverse genomes from sea anemone to human, imply a very significant biological function for this enzyme. In C. capitata, two forms of RNase kappa mRNA (0.9 and 1.5 kb) with various lengths of 3' UTR were identified as alternative products of a single gene, resulting from the use of different polyadenylation signals. Both transcripts are expressed in all insect tissues and developmental stages. Sequence analysis of the extended region of the longer transcript revealed the existence of three mRNA instability motifs (AUUUA) and five poly(U) tracts, whose functional importance in RNase kappa mRNA decay remains to be explored.
authors.affiliation: Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Athens, Greece.
authors.forename: Theodoros N
authors.initials: TN
authors.lastname: Rampias
authors.forename: Emmanuel G
authors.initials: EG
authors.lastname: Fragoulis
authors.forename: Diamantis C
authors.initials: DC
authors.lastname: Sideris
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D012831:Bombyx / Q000201:enzymology / Q000235:genetics; D033622:Ceratitis capitata / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004722:Endoribonucleases / Q000235:genetics* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D049750:Genome, Insect; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013045:Species Specificity
chemical_list: D019476:Insect Proteins; D020033:Protein Isoforms; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D004722:Endoribonucleases; C065559:ribonuclease K