Project description:RNA editing is a crucial post-transcriptional process that diversifies proteomic outcomes and influences gene expression. Particularly, the APOBEC3 family has emerged as a significant player in this mechanism, with APOBEC3A (A3A) showing notable roles in immune response and stress conditions. APOBEC3B (A3B), another family member, has garnered attention for its potential role in breast cancer genomic mutations. In this study, we employ an inducible expression cell model and eCLIP-seq to detect the RNA binding sites for A3B a breast cancer cell model. Our findings indicate that A3B engages in selective RNA editing and targets NEAT1 and MALAT1 long non-coding RNAs. Notably, the binding of these RNAs sequesters A3B’s catalytic activity, and thereby affects A3A’s activity through a feedback loop.
Project description:UV cross-linking and immunoprecipitation (CLIP) methodologies enable the identification of RNA binding sites of RNA-binding proteins (RBPs). Despite improvements in the library preparation of RNA fragments, the current enhanced CLIP (eCLIP) protocol still requires ~4 days of hands-on time and lacks the ability to scale. We present a new method termed antibody barcode CLIP (ABC) that utilizes DNA-barcoded antibodies to multiplex CLIP detection methods. We demonstrate the scalability and simplicity of ABC by performing CLIP on multiple RBPs simultaneously, minimizing sample-to-sample variation, and maintaining the same material requirement for a single eCLIP experiment.
Project description:eCLIP was performed for ENO1 in HeLa cells, following the protocol described by Van Nostrand et al. (2016). Libraries for six immunoprecipitation and size-matched input controls were produced. In addition, libraries were produced for two no-crosslinking controls. The libraries were sequenced using paired-end sequencing (PE125) on an Illumina HiSeq2000 platform.
Project description: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.
Project description: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.
Project description:Enhanced CLIP (eCLIP) enables robust and scalable transcriptome-wide discovery and characterization of RNA binding protein binding sites