Project description:C2C12 cells were UV-irradiated at 400 mJ, and whole cell lysates were harvested from the cells. tRIP was performed as previously described (Masuda et al). Samples were sequenced on the Illumina NovaSeq6000 with 150 bp paired-end read (Macrogen, Japan) or Miseq with 150 bp single-read at the core facility of the Nagoya University. For paired-end read data, only P5 reads were used for analysis. Briefly, after standard HiSeq demultiplexing, reads were adapter-trimmed and reads less than 18 bp were discarded using cutadapt (v1.10). Mapping was first performed against the mouse repetitive elements in RepBase with STAR (v2.5.2b). Repeat-mapped reads were removed, and all others were then mapped against the mouse genome (mm10) with STAR (v 2.5.2b). Multiply mapped reads were filtered out. Duplicates of reads uniquely mapped to the human or mouse genome were removed by Picard (v2.0.1).
Project description:Cleavage factor I mammalian (CFIm) complex, composed of cleavage and polyadenylation specificity factor CPSF6, regulates alternative polyadenylation (APA). CPSF6 has a RS-like domain which plays role in protein -protein interactions. This interaction might have role in alternative polyadenylation site selection. The phosphorylation of RS- like domain might play role in protein -protein interaction and thus might have a role in alternative polyadenylation site selection. So we did mass specteroanalysis to analyse phosphorylation sites of RS-like domain of CPSF6.
Project description:Alternative polyadenylation (APA) refers to the regulated selection of polyadenylation sites (PASs) in transcripts, which determines the length of their 3’ untranslated regions (3’UTRs). APA regulates stage- and tissue-specific gene expression by affecting the stability, subcellular localization and translation rate of transcripts. We have recently shown that SRSF3 and SRSF7, two closely related SR proteins, connect APA with mRNA export. The mechanism underlying APA regulation by SRSF3 and SRSF7 remained, however, unknown. Here, we combined iCLIP, RNA-Seq and 3’-end sequencing to find that both proteins bind upstream of proximal PASs (pPASs), yet they exert opposite effects on 3’UTR length. We show that SRSF7 enhances pPAS usage in a concentration-dependent but splicing-independent manner by recruiting the cleavage factor FIP1, thereby generating short 3’UTRs. Protein domains unique to SRSF7, which are absent from SRSF3, and hypo-phosphorylation contribute to FIP1 recruitment. In contrast, SRSF3 promotes distal PAS (dPAS) usage and hence long 3’UTRs by maintaining high levels of cleavage factor Im (CFIm) via alternative splicing. Upon reduced expression of SRSF3, CFIm levels strongly decrease and 3’UTRs are globally shortened. In SRSF3-regulated transcripts, CFIm and FIP1 bind upstream of dPASs and promote their usage. Surprisingly, both factors are also recruited to pPASs under conditions where their usage is blocked, suggesting the formation of inactive cleavage complexes. Thus, we identify SRSF3 as a novel regulator of CFIm activity, provide evidence that CFIm inhibits pPAS usage and show that small differences in the domain architecture of SR proteins confer opposite effects on PAS selection.
Project description:In this study, we showed that CPSF6 promoted HCC cell growth, migration and metastasis in vitro and in vivo. In order to understand the underlying mechanisms of CPSF6, we aimed to perform a APA profiling analysis in hepatocyte and hepatoma carcinoma cells under different CPSF6 expression conditions using 3T-seq method.
Project description:In this study, we showed that knockdown of CPSF6 inhibited GC cell growth and promoted apoptosis in vitro and in vivo. In order to understand the underlying mechanisms of CPSF6, we performed an APA profiling analysis in wild-type and CPSF6-knockdown AGS cells, using 3T-seq method.
Project description:Ewing sarcoma is a highly aggressive tumor characterized by a translocation between members of the FET family of RNA binding proteins and one of several ETS transcription factors, with the most common translocation being EWS-FLI1. EWS-FLI1 leads to changes in gene expression through mechanisms that are not completely understood. We performed RNA sequencing analysis on primary pediatric human mesenchymal progenitor cells (pMPCs) expressing EWS-FLI1 in order to identify novel target genes. This analysis identified lnc277 as a previously uncharacterized long non-coding RNA upregulated by EWS-FLI1 in pMPCs. Inhibiting the expression of lnc277 diminished the ability of Ewing sarcoma cell lines to proliferate and form colonies in soft agar whereas inhibiting lnc277 had no effect on other cell types tested. By analyzing gene expression after shRNA knockdown, we found that both EWS-FLI1 and lnc277 repressed many more genes that they induced and that a significant fraction of EWS-FLI1 repressed targets were also repressed by lnc277. Analysis of primary human Ewing sarcoma RNA sequencing data further supports a role for lnc277 in mediating gene repression. We identified hnRNPK as an RNA binding protein that interacts directly with lnc277. We found a significant overlap in the genes repressed by hnRNPK and those repressed by both EWS-FLI1 and lnc277, suggesting that hnRNPK participates in lnc277 mediated gene repression. Thus, lnc277 is a previously uncharacterized long non-coding RNA downstream of EWS-FLI1 that facilitates the development of Ewing sarcoma via the repression of target genes. Our studies identify a novel mechanism of oncogenesis downstream of a chromosomal translocation and underscore the importance of lncRNA-mediated gene repression as a mechanism of EWS-FLI1 transcriptional regulation. A673 Ewing cells expressing an shRNA targeting hnRNPK or control were subjected to paired end RNA sequencing and compared to shGFP control.
Project description:To verify the effect of phosphorylation of CPSF6 by CLK2 on APA, we co overexpressed CLK2 and wild-type CPSF6 or phosphorylated mutant CPSF6 in HEK293T cells
Project description:Several members of SRSF family play wide-ranging roles in the regulation of transcription and post-splicing processes as well as splice sites selection. Although the expression of SRSF3 was reported to be overexpressed in several cancers, the roles of SRSF3 in the cancer cells are almost unknown. We analyzed differentially expressed genes in SRSF3 siRNA-treated HCT116 cells and identified the specific pathways regulated by SRSF3. After treatment of HCT116 cells with SRSF3 (sample 02) or control (sample 01) siRNA, total RNA was extracted using RNeasy Mini Kit (Qiagen, Valencia, CA). The quality of the purified RNA and its applicability for microarray analysis were assessed by the Agilent 2100 Bioanalyzer using a RNA 6000 Nano Labchip kit (Agilent Technologies, Palo Alto, CA, USA). Total RNA (400 ng) was used for amplification, labeling and hybridization to a whole human genome oligoDNA microarray (4x44k; Agilent) according to the manufacture’s instructions.