Stalled spliceosomes are a signal for RNAi-mediated genome defense

ABSTRACT: Using the yeast Cryptococcus neoformans, we describe a mechanism by which transposons are initially targeted for RNAi-mediated genome defense. We show that intron-containing mRNA precursors template siRNA synthesis. We identify a Spliceosome-Coupled And Nuclear RNAi (SCANR) complex required for siRNA synthesis and demonstrate that it physically associates with the spliceosome. We find that RNAi target transcripts are distinguished by suboptimal introns and abnormally high occupancy on spliceosomes. Functional investigations demonstrate that the stalling of mRNA precursors on spliceosomes is required for siRNA accumulation. Lariat debranching enzyme is also necessary for siRNA production, suggesting a requirement for processing of stalled splicing intermediates. We propose that recognition

ORGANISM(S): Cryptococcus neoformans

SUBMITTER: Phillip Dumesic 

PROVIDER: E-GEOD-43363 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress