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:Epithelial-mesenchymal interactions are crucial for the development of multiple animal structures. Thus, unraveling how molecular tools are recruited in different lineages to control the interplay between these tissue types is key to understand morphogenetic evolution. Here, we studied Epithelial Splicing Regulatory Protein (Esrp) genes, which regulate extensive alternative splicing programs associated with cell adhesion and motility in human cells and are essential during mouse organogenesis. We found that Esrp genes are involved in the development of many structures in deuterostome organisms, often by conferring epithelial-associated cellular properties. However, this common employment of Esrp in morphogenetic functions was not mirrored at the exon level at the largest phylogenetic distances, as no Esrp-dependent exons appeared conserved between phyla. A remarkable phylum-specific event was observed in the Fgfr gene family, which was recruited as an Esrp target in stem chordates and subsequently co-opted into developmental programs of multiple novel traits in vertebrates.
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. RNA from purified total epidermis (basal keratinocyte layer to cornified layer) of E18.5 mouse embryos were harvested by Trizol extraction. (Esrp1+/+, Esrp2-/- (n=2), Esrp1-/-, Esrp2+/+ (n=3), Esrp1-/-, Esrp2+/- (n=2), and Esrp1-/-, Esrp2-/- (n=2). 1 ug of total RNA was used for for RNA-seq library preparation using the TruSeq™ Stranded mRNA LT Sample Prep Kit (Illumina). 100x2 bp paired-end RNA-seq reads were generated on a HiSeq 2000 sequencer.
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:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
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.