A nematode-specific ribonucleoprotein complex mediates interactions between the major nematode spliced leader snRNP and its target pre-mRNAs.

Spliced leader trans-splicing of pre-mRNAs is a critical step in the gene expression of many eukaryotes. How the spliced leader RNA and its target transcripts are brought together to form the trans-spliceosome remains an important unanswered question. Using immunoprecipitation followed by protein analysis via mass spectrometry and RIP-Seq, we show that the nematode-specific proteins, SNA-3 and SUT-1, form a complex with a set of enigmatic non-coding RNAs, the SmY RNAs.

A novel, essential trans-splicing protein connects the nematode SL1 snRNP to the CBC-ARS2 complex.

Spliced leader trans-splicing is essential for gene expression in many eukaryotes. To elucidate the molecular mechanism of this process, we characterise the molecules associated with the Caenorhabditis elegans major spliced leader snRNP (SL1 snRNP), which donates the spliced leader that replaces the 5' untranslated region of most pre-mRNAs. Using a GFP-tagged version of the SL1 snRNP protein SNA-1 created by CRISPR-mediated genome engineering, we immunoprecipitate and identify RNAs and protein components by RIP-Seq and mass spectrometry.