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.
Project description:The goal of this study is to analyse the transcriptome of control hearts vs hearts lacking SRSF3 expression and to analyse binding preferences of SRSF3 in cardiac myocytes.
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.
Project description:SRSF3 is overexpressed in human invasive ovarian cancer and its overexpression is required for cancer cell growth and survival. To decipher the mechnisms behind the role of SRSF3 in ovarian cancer, we examined the gene expression and splicing in the ovarian cancer cell line that was engineered to express a doxycycline-induced SRSF3 siRNA, which was able to knockdown SRSF3 expression by 90% and induce apoptosis. Total RNAs extracted from A2780/SRSF3si2, a subline of ovarian cancer cell line A2780, treated with or without doxycycline at 0.1ug/ml for three days were analyzed using Affymetrix GeneChip® Human Exon 1.0 ST Array
Project description:Serine-rich splicing factor 3 (SRSF3) was recently reported as being necessary to preserve RNA stability via an mTOR mechanism in a cardiac mouse model in adulthood. Here, we demonstrate the link between Srsf3 and mitochondrial integrity in an embryonic cardiomyocyte-specific Srsf3 conditional knockout (cKO) mouse model. Fifteen-day-old Srsf3 cKO mice showed dramatically reduced (below 50%) survival and reduced the left ventricular systolic performance, and histological analysis of these hearts revealed a significant increase in cardiomyocyte size, confirming the severe remodeling induced by Srsf3 deletion. RNA-seq analysis of the hearts of 5-day-old Srsf3 cKO mice revealed early changes in expression levels and alternative splicing of several transcripts related to mitochondrial integrity and oxidative phosphorylation. Likewise, the levels of several protein complexes of the electron transport chain decreased, and mitochondrial complex I-driven respiration of permeabilized cardiac muscle fibers from the left ventricle was impaired. Furthermore, transmission electron microscopy analysis showed disordered mitochondrial length and cristae structure. Together with its indispensable role in the physiological maintenance of mouse hearts, these results highlight the previously unrecognized function of Srsf3 in regulating the mitochondrial integrity.
Project description:SRSF3 is overexpressed in human invasive ovarian cancer and its overexpression is required for cancer cell growth and survival. To decipher the mechnisms behind the role of SRSF3 in ovarian cancer, we examined the gene expression and splicing in the ovarian cancer cell line that was engineered to express a doxycycline-induced SRSF3 siRNA, which was able to knockdown SRSF3 expression by 90% and induce apoptosis.
Project description:We have independently knocked down TRA2B and SRSF3 in HEK293 cells to identify the sum of alternative splicing changes that results from depletion of each factor. Each was compared to a control transfection of the hairpin vector alone. In this set, 9 total samples were analyzed. There were three biological replicates for each of three conditions: knockdown control, TRA2B knockdown and SRSF3 knockdown. Arrays were analyzed for gene expression using GeneBase and for alternative splicing using MADS+ and OmniViewer software.
Project description:Signaling through the platelet-derived growth factor receptor alpha (PDGFRa) is critical for mammalian craniofacial development, though the mechanisms by which the activity of downstream intracellular effectors is regulated to mediate gene expression changes have not been defined. We find that the RNA-binding protein Srsf3 is phosphorylated at Akt consensus sites downstream of PI3K-mediated PDGFRa signaling in palatal mesenchyme cells, leading to its nuclear translocation. We further demonstrate that ablation of Srsf3 in the neural crest lineage leads to facial clefting due to defective cranial neural crest cell specification and survival. Finally, we show that Srsf3 regulates the alternative RNA splicing of transcripts encoding protein kinases in the facial process mesenchyme to negatively regulate PDGFRa signaling. Collectively, our findings reveal that PI3K/Akt-mediated PDGFRa signaling primarily modulates gene expression through alternative RNA splicing in the facial mesenchyme and identify Srsf3 as a critical regulator of craniofacial development.
Project description:RNA seqeuncing was performed to identifiy changes in genes expression and alternative splicing following SRSF3 depletion in pluripotent stem cells.
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.