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The spliceosomal PRP19 complex of trypanosomes

Daniela L Ambrósio1, Nitika Badjatia, Arthur Günzl

  • 1Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT, 06030-6403, USA.

Molecular Microbiology
|December 20, 2014
PubMed

Insights

Researchers identified the PRP19 complex in Trypanosoma brucei, revealing its role in spliceosome activation. Silencing SPF27 disrupted spliced leader trans-splicing, highlighting its importance in mRNA processing.

Area of Science:

  • Molecular Biology
  • Parasitology
  • RNA Biology

Background:

  • Trypanosomes utilize spliced leader (SL) trans-splicing for mRNA processing, a mechanism involving the spliceosome.
  • Identifying trypanosome splicing factors is challenging due to evolutionary divergence from eukaryotic orthologs.
  • Most characterized splicing factors are snRNP proteins; intact spliceosomes remain difficult to purify.

Purpose of the Study:

  • To characterize the non-snRNP PRP19 complex in Trypanosoma brucei.
  • To investigate the role of the PRP19 complex in spliceosome function and mRNA processing.

Main Methods:

  • Proteomic analysis to identify components of the PRP19 complex.
  • RNA interference (RNAi) to silence specific genes (e.g., SPF27).
  • Analysis of SL RNA accumulation and cap methylation status.

Main Results:

  • The PRP19 complex comprises core subunits PRP19, CDC5, PRL1, SPF27, and additional proteins PRP17, SKIP, and PPIL1.
  • Three novel proteins were identified within this complex.
  • SPF27 silencing inhibited the first step of splicing and caused accumulation of hypomethylated SL RNA.
  • The observed defect mimicked that of CRK9 depletion, suggesting a functional link.

Conclusions:

  • The identified PRP19 complex is a key component of the activated spliceosome in trypanosomes.
  • SPF27 and potentially CRK9 play critical roles in spliceosome activation.
  • This study advances the understanding of mRNA processing machinery in a unique eukaryotic system.

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