Spliced leader RNA trans-splicing in dinoflagellates

• DOI: 10.1073/pnas.0700258104
• Publication Date: 2007-03-03T02:12:25Z
• Authors: Huan Zhang; Yubo Hou; Lilibeth Miranda; David A. Campbell; Nancy R. Sturm; Terry Gaasterland; Senjie Lin
• Keywords: RNA recognition motif; Conserved sequence; Trans-splicing; SR protein

Through the analysis of hundreds full-length cDNAs from fifteen species representing all major orders dinoflagellates, we demonstrate that nuclear-encoded mRNAs in species, ancestral to derived lineages, are trans-spliced with addition 22-nt conserved spliced leader (SL), DCCGUAGCCAUUUUGGCUCAAG (D = U, A, or G), 5' end. SL trans-splicing has been documented a limited but diverse number eukaryotes, which this process makes it possible translate polycistronically transcribed nuclear genes. In trans-splicing, SL-donor transcripts (SL RNAs) contain two functional domains: an exon provides for mRNA and intron contains spliceosomal (Sm) binding site. RNAs unusually short at 50-60 nt, Sm motif (AUUUUGG) located (exon) rather than intron. The initiation nucleotide is predominantly U unusual feature may affect capping, hence translation stability recipient mRNA. core element was found coding array proteins. Among characterized were three homologs Sm-complex subunits, indicating role site conserved, even if location on not. Because association often signals import U-rich small RNAs, unclear how remains mature without impeding cytosolic localization latter. sequences reported paper have deposited GenBank database (accession nos. AF 512889, DQ 864761-DQ 864971, 867053-DQ 867070, 884413-DQ 884451, EF 133854-EF 133905, 133961-EF 134003, 134083-EF 134402, 141835, 143070-EF 143105).