SnRNA-specific role of SMN in trypanosome snRNP biogenesis in vivo.

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 nucle

SUBMITTER: Jae N 

PROVIDER: S-EPMC3127081 | biostudies-literature | 2011 Jan-Feb

REPOSITORIES: biostudies-literature