GSE77339
GSE GEOEnhanced CLIP (eCLIP) enables robust and scalable transcriptome-wide discovery and characterization of RNA binding protein binding sites [array]
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Summary
RNA binding proteins (RBPs) play essential roles in cellular physiology by interacting with target RNAs. As defects in protein-RNA recognition lead to human disease, UV-crosslinking and immunoprecipitation (CLIP) of ribonuclear complexes followed by deep sequencing (-seq) is critical in constructing protein-RNA maps to expand our understanding of RBP function. However, current CLIP protocols are technically demanding and involve low complexity libraries that yield squandered sequencing of PCR duplicates and high experimental failure rates. To enable truly large-scale implementation of CLIP-seq, we have developed an enhanced CLIP methodology (eCLIP) that features a decrease of ~10 cycles of requisite amplification with a concomitant >60% decrease in discarded PCR duplicate reads, while maintaining the ability to identify RNA binding with single-nucleotide resolution. By simplifying the generation of paired IgG and size-matched input controls, eCLIP also dramatically improves specificity in discovery of authentic binding sites. To demonstrate that eCLIP enables large-scale and robust profiling of RBPs, 102 eCLIP experiments in biological duplicate for a diverse collection of 74 RBPs in HepG2 and K562 cells were completed (available at https://www.encodeproject.org). We establish that eCLIP is comparable in amplification and sample requirements to ChIP-seq, and enables integrative analysis of diverse RBPs to reveal factor-specific profiles, common artifacts for CLIP experiments and RNA-centric perspectives of RBP activity.
Overall Design
Microarray profiling of RBFOX2 knockdown by shRNAs in 293T cells
Analysis (7 steps)
View Data Processing- Cel files were analyzed using Expression Console (build 1.4.1.46, Affymetrix), with RMA normalization and DABG probe-level detection.
- Only probesets with detection p-value ⤠0.05 in more than half of the microarray samples were considered for downstream analysis.
- All probes corresponding to cassette exons profiled on the microarray (comprising exclusion junction, upstream and downstream inclusion junction, and inclusion exonic probes) were identified and normalized against the average signal on a per-gene basis to remove gene expression changes.
- Studentâs t-test was performed on residuals for inclusion probes and exclusion probes separately to identify robust splicing changes, which were quantified by SepScore ( defined as the normalized change in exclusion minus the normalized change in inclusion).
- HTA-2_0.r1.pgf
- HTA-2_0.r1.Psrs.mps
- RMA probeset-level signal estimates, DABG detection flag (Absent or Present), and DABG detection p-value obtained from 'Alt Splice Analysis' performed in Affymetrix Expression Console build 1.4.1.46.