ABSTRACT: Multiphasic and dynamic changes in alternative splicing during induction of pluripotency are coordinated by numerous RNA binding proteins [ESRP DKO]
Project description:Multiphasic and dynamic changes in alternative splicing during induction of pluripotency are coordinated by numerous RNA binding proteins
Project description:Multiphasic and dynamic changes in alternative splicing during induction of pluripotency are coordinated by numerous RNA binding proteins [iPS]
Project description:Alternative splicing (AS) plays a critical role in cell fate transitions, development and disease. Recent studies have shown that AS also influences pluripotency and somatic cell reprogramming. We profiled transcriptome-wide AS changes that occur during reprogramming of fibroblasts to pluripotency. This analysis revealed distinct phases of AS during reprogramming, including a splicing program that is unique to transgene-independent iPS cells. Changes in the expression of alternative splicing factors Zcchc24, Esrp1, Mbnl1/2 and Rbm47 were demonstrated to be key contributors to phase-specific AS. RNA binding motif enrichment analysis near alternatively spliced exons provided further insight into the combinatorial regulation of AS during reprogramming by different RNA binding proteins. Ectopic expression of Esrp1 enhanced reprogramming, in part by modulating the AS of the epithelial specific transcription factor Grhl1.These data represent a comprehensive temporal analysis of the dynamic regulation of AS during the acquisition of pluripotency. ES cells from 3 independent E3.5 blastocysts from either Control (Esrp1 WT/WT; Esrp2 -/-) or Esrp DKO (Esrp1 floxed/floxed; Esrp2 -/-) were transfected with pLVX-EGFP-Cre, puro selected and RNA was isolated 6 days later.
Project description:Alternative splicing achieves coordinated changes in post-transcriptional gene expression programs through the activities of diverse RNA binding proteins. Epithelial Splicing Regulatory Proteins 1 and 2 (ESRP1 and ESRP2) are cell type-specific regulators of transcripts that switch splicing during the Epithelial Mesenchymal Transition (EMT). To define a comprehensive program of alternative splicing that is regulated during the EMT, we identified an extensive ESRP-regulated splicing network of hundreds of alternative splicing events within numerous genes with roles in cell-cell adhesion, polarity, and migration. Loss of this global ESRP-regulated epithelial splicing program induces the phenotypic changes in cell morphology that are observed during the EMT. Components of this splicing signature provide novel molecular markers that can be used to characterize the EMT. Bioinformatics and experimental approaches revealed a high affinity ESRP binding motif and a predictive RNA map that governs their activity. This work establishes the ESRPs as coordinators of a complex alternative splicing network that adds an important post-transcriptional layer to the changes in gene expression that underlie epithelial-mesenchymal transitions during development and disease. Keywords: control / knockdown comparison and control / ectopic expression comparison
Project description:Epithelial Splicing Regulatory Proteins 1 and 2 (ESRP1 and ESRP2) are recently discovered epithelial-specific RNA-binding proteins that promote splicing of the epithelial variant of the FGFR2, ENAH, CD44, and CTNND1 transcripts. To catalogue a larger set of splicing events under the regulation of the ESRPs, we profiled splicing changes induced by RNA interference-mediated knockdown of ESRP1 and ESRP2 expression in a human epithelial cell line using the splicing-sensitive Affymetrix Exon ST1.0 Arrays. Analysis of the microarray data using the previously described MADS tool resulted in the identification of over a hundred candidate ESRP-regulated splicing events. We were able to independently validate 37 of these targets by RT-PCR. The ESRP-regulated events encompass all known types of alternative splicing events. Importantly, a number of these regulated splicing events occur in gene transcripts that encode proteins with well-described roles in the regulation of actin cytoskeleton organization, cell-cell adhesion, cell polarity, and cell migration. In sum, this work reveals a novel list of transcripts differentially spliced in epithelial and mesenchymal cells, implying that coordinated alternative splicing plays a critical role in determination of cell type identity. Keywords: control / knockdown comparison
Project description:Epithelial Splicing Regulatory Proteins 1 and 2 (ESRP1 and ESRP2) are recently discovered epithelial-specific RNA-binding proteins that promote splicing of the epithelial variant of the FGFR2, ENAH, CD44, and CTNND1 transcripts. To catalogue a larger set of splicing events under the regulation of the ESRPs, we profiled splicing changes induced by RNA interference-mediated knockdown of ESRP1 and ESRP2 expression in a human epithelial cell line using the splicing-sensitive Affymetrix Exon ST1.0 Arrays. Analysis of the microarray data using the previously described MADS tool resulted in the identification of over a hundred candidate ESRP-regulated splicing events. We were able to independently validate 37 of these targets by RT-PCR. The ESRP-regulated events encompass all known types of alternative splicing events. Importantly, a number of these regulated splicing events occur in gene transcripts that encode proteins with well-described roles in the regulation of actin cytoskeleton organization, cell-cell adhesion, cell polarity, and cell migration. In sum, this work reveals a novel list of transcripts differentially spliced in epithelial and mesenchymal cells, implying that coordinated alternative splicing plays a critical role in determination of cell type identity. Keywords: control / knockdown comparison Short interfering knockdown of ESRP1 and ESRP2 in human PNT2 prostatic epithelium cells was performed as described before (Warzecha et al., 2009, Molecular Cell 33:591-601). The efficiency of ESRP1 and ESRP2 knockdown was monitored by quantitative RT-PCR as described before (Warzecha et al., 2009, Molecular Cell 33:591-601). In all cases the efficiency of the knockdown was close to 80%. We conducted Exon array profiling on RNAs from four siESRP1/2-treated samples and four siGFP controls.
Project description:Tissue- and cell-type specific regulators of alternative splicing (AS) are an essential layer of posttranscriptional gene regulation necessary for normal cellular function, patterning, and development. Here we report the Epithelial splicing regulatory proteins (Esrps) are required for patterning of multiple organs, with loss of both paralogs, Esrp1 and Esrp2, resulting in increasingly severe phenotypes. Global profiling of the Esrp splicing regulatory network from total epidermis revealed varied splicing sensitivity of Esrp targets upon loss of Esrp1 or double knockout. This may explain the progressive phenotypes seen in Esrp knockout mice, and these mice provide a unique genetic tool to evaluate functional consequences of epithelial splicing events in vivo.
Project description:We provide data showing alternative splicing regulation by Muscleblind proteins in MEFs. MEFs lacking functional Muscleblind (DKO MEFs) were stably reconstituted with Muscleblind proteins from Homo sapiens, Ciona intestinalis, Drosophila melanogaster, Caenorhabditis elegans or Trichoplax adhaerens and splicing regulation was explored using RNA-seq analysis followed by MISO (Mixture of Isoforms). Alternative splicing was accessed using RNA-sequencing data from five DKO MEF lines reconstituted with different GFP-tagged Muscleblind homologs or GFP alone and compared to RNA-seq data from three WT MEF lines and three control DKO MEFs (no Muscleblind reconstitution). A total of 12 samples were used for high-throughput sequencing.