Yeast exosome: immunoprecipitation 2

ABSTRACT: Nuclear RNA degradation pathways are highly conserved across eukaryotes and play important roles in RNA quality control. Key substrates for exosomal degradation include aberrant functional RNAs and cryptic unstable transcripts (CUTs). It has recently been reported that the nuclear exosome is inactivated during meiosis in budding yeast through degradation of the subunit Rrp6, leading to the stabilisation of a subset of meiotic unstable transcripts (MUTs) of unknown function. We have analysed the activity of the nuclear exosome during meiosis by deletion of TRF4, which encodes a key component of the exosome targeting complex TRAMP. We find that TRAMP mutants produce high levels of CUTs during meiosis which are undetectable in wild-type cells, suggesting that the nuclear exosome remains functional, and we further show that the meiotic exosome complex still contains Rrp6. Indeed Rrp6 over-expression is insufficient to suppress MUT transcripts, showing that the reduced amount of Rrp6 in meiotic cells does not directly cause MUT accumulation. Lack of TRAMP activity stabilises ~1600 CUTs in meiotic cells, which occupy 40% of the binding capacity of the nuclear cap binding complex (CBC). CBC mutants display defects in the formation of meiotic double strand breaks (DSBs), and we see similar defects in TRAMP mutants, suggesting that a key function of the nuclear exosome is to prevent saturation of the CBC complex by CUTs. Together, our results show that the nuclear exosome remains active in meiosis and has an important role in facilitating meiotic recombination.

OTHER RELATED OMICS DATASETS IN: PRJNA257783

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: David Oxley  

LAB HEAD: David Oxley

PROVIDER: PXD001239 | Pride | 2015-05-15

REPOSITORIES: Pride