Journal article

Publication year: 2011

Pages: 90-100

Journal: RNA Biology

Volume number: 8

Issue number: 1

ISSN: 1547-6286

eISSN: 1555-8584

Open access status: Green

DOI Link: https://doi.org/10.4161/rna.8.1.13985

Publisher: Taylor and Francis Group

Abstract: 
Pre-mRNA splicing in trypanosomes requires the SMN-mediated assembly of small nuclear ribonucleoproteins (snRNPs). In contrast to higher eukaryotes, the cellular localization of snRNP biogenesis and the involvement of nuclear-cytoplasmic trafficking in trypanosomes are controversial. By using RNAi knockdown of SMN in T. brucei to investigate its functional role in snRNP assembly, we found dramatic changes in the steady-state levels of snRNAs and snRNPs: The SL RNA accumulates, whereas U1, U4 and U5 snRNA levels decrease, and Sm core assembly in particular of the SL RNA is strongly reduced. In addition, SMN depletion blocks U4/U6 di-snRNP formation; the variant Sm core of the U2 snRNP, however, still forms efficiently after SMN knockdown. Concerning the longstanding question, whether nuclear-cytoplasmic trafficking is involved in trypanosomal snRNP biogenesis, fluorescence in situ hybridization (FISH) and immunofluorescence assays revealed that the SL RNA genes and transcripts colocalize with SMN. Remarkably, SMN silencing leads to a nucleoplasmic accumulation of both SL RNA and the Sm proteins. In sum, our data demonstrate an essential and snRNA-selective role of SMN in snRNP biogenesis in vivo and strongly argue for a nucleoplasmic Sm core assembly of the SL RNP.

Harvard Citation style: Jae, N., Preußer, C., Krüger, T., Tkacz, I., Engstler, M., Michaeli, S., et al. (2011) snRNA-specific role of SMN in trypanosome snRNP biogenesis in vivo, RNA Biology, 8(1), pp. 90-100. https://doi.org/10.4161/rna.8.1.13985

APA Citation style: Jae, N., Preußer, C., Krüger, T., Tkacz, I., Engstler, M., Michaeli, S., & Bindereif, A. (2011). snRNA-specific role of SMN in trypanosome snRNP biogenesis in vivo. RNA Biology. 8(1), 90-100. https://doi.org/10.4161/rna.8.1.13985