Dataset Information

Frac-Seq Analysis of ZFC3H1 Knockdown U2OS Cells

ABSTRACT: We have found that depletion of the zinc finger protein ZFC3H1 inhibits the nuclear retention of these RNAs. ZFC3H1 forms a complex with MTR4 and PABPN1 (the PolyAdenylation EXosome Targeting complex (Meola et al 2016, Ogami et al 2017) and likely recruits the nuclear exosome for RNA degradation. Recently, we found that depletion of U1-70K, one protein component of the U1 snRNP spliceosomal complex, inhibits nuclear retention of 5’SS motif containing RNAs. The U1 snRNP complex recognizes and binds to the 5’SS motif and in vitro studies showed that U1-70K directly interact with a similar 5’SS motif through U1 snRNA binding (Gunderson et al 1999). Interestingly, we found that U1 snRNP is involved in targeting 5’SS motif containing mRNAs to nuclear speckles shortly following RNA transcription. In contrast, ZFC3H1 is involved in nuclear speckle localization post-transcriptionally and actively retain RNAs in these structures. Together, our results suggest a model where U1 snRNP interacts with the RNA via the 5’SS motif and targets mature mRNAs to nuclear speckles. Specifically, it suggests that misprocessed RNAs can be targeted to speckles (or other nucleoplasmic foci) and that these foci serve as a platform to recruit the nuclear exosome via ZFC3H1. Our results highlight a splicing independent role of U1 snRNP and how mRNA nuclear export function in nuclear surveillance to prevent the translation of aberrant proteins.

ORGANISM(S): Homo sapiens

PROVIDER: GSE176144 | GEO | 2022/03/31

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Pervasive transcription in the mammalian genome produces thousands of long noncoding RNAs (lncRNAs) and promoter- or enhancer-associated unstable transcripts. They preferentially locate to chromatin, at which some regulate chromatin structure, transcription and RNA processing. While several RNA sequences responsible for nuclear localization have been identified, such as repeats in the lncRNA Xist and Alu-like elements for long RNAs, how lncRNAs as a class are enriched on chromatin remains elusive. To screen for cis-elements that contribute to RNA-chromatin localization, we developed a high-throughput method named RNA elements for subcellular localization by sequencing (REL-seq), and discovered a U1 small nuclear ribonucleoprotein (snRNP)-recognition motif being critical for chromatin localization of reporter RNAs. Across the genome, chromatin-bound lncRNAs, which are enriched with 5’ splice sites and depleted of 3’ splice sites, exhibit high levels of U1 snRNA binding compared to cytoplasm-localized protein-coding mRNAs. Acute depletion of U1 snRNA, or U1 snRNP protein component SNRNP70, drastically reduces the chromatin association of hundreds of lncRNAs and unstable transcripts without altering the overall transcription rate in cells. In addition, rapid degradation of SNRNP70 reduces the localization of both nascent and polyadenylated lncRNA transcripts to chromatin, and disrupts the nuclear-speckles and genome-wide localization of Malat1, a highly conserved and abundant lncRNA. Moreover, chromatin-bound U1 snRNP interacts with transcriptionally engaged RNA polymerase (Pol) II. Together, these results demonstrate that U1 snRNP acts widely to tether and mobilize lncRNAs to chromatin in a Pol II transcription-dependent manner. Our findings uncover a novel role of U1 snRNP beyond pre-mRNA processing and provide molecular insights into how lncRNAs are recruited to Pol II-transcribed genes and have a propensity for chromatin-associated functions.

Dataset Information

Frac-Seq Analysis of ZFC3H1 Knockdown U2OS Cells

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure