Project description:SRSF1 is an abundant RNA-binding protein with functions in mRNA splicing, stability, translation and transcription of cellular and viral genes. We analyzed the role that SRSF1 plays in cellular gene transcription and splicing by transfecting HEK293 cells with a SRSF1 expression plasmid and by analyzing the transcriptome of the transiently transfected cells 15 hrs and 48 hrs post transfection. We also explored the role of the SRSF1 domains by transfecting a deletion clone of SRSF1 carrying only the RNA Recognition Motifs 1 and 2 (RRM1,2) but not the Arg-Ser rich (SR) domain.
Project description:Post-transcriptional gene regulatory mechanisms (PTGRM) contribute profoundly to liver development and physiology. Alternative splicing is one of the earliest mechanisms of gene regulation acting on nascently transcribed mRNA. This process is mediated by a large class of proteins known as splicing factors. SRSF1 is a canonical splicing factor with roles in both constitutive and alternative splicing. While its biochemical activities have been studied extensively, its role in tissue physiology are not well defined. In this study we investigate the role of SRSF1 in liver physiology using hepatocyte-specific knock-out mice models. Hepatocyte-specific knock-out of SRSF1 was achieved in two ways; 1) SRSF1 floxed mice were crossed with AlbCre transgenic mice and 2) SRSF1 floxed mice were injected with AAV8-TBG-iCre viral vector. The latter model allowed for investigating acute changes in hepatocyte upon ablation of SRSF1. Both models exhibit acute liver injury with severe cellular damage, inflammation and lipid accumulation. Utilizing high-throughput transcriptome profiling on purified hepatocytes, we find acute loss of SRSF1 triggers activation of the p53 pathway and splicing dysregulation of genes involved in mRNA metabolism. Continuous hepatic injury in this model eventually triggers a regenerative response resulting in the upregulation of genes involved in proliferation and repopulation of the tissue parenchyma.
Project description:The SR protein family of splicing factors regulate constitutive and alternative pre-mRNA splicing. A subset of them, including SRSF1, shuttles continuously between the nucleus and cytoplasm affecting post-splicing processes. We have previously identified a role for SRSF1 in promoting the translation of specific mRNA transcripts, particularly those encoding centrosomal proteins. Here, we used CRISPR/Cas9 editing to knock-in a nuclear retention signal (NRS) in Srsf1 resulting in a non-shuttling SRSF1 mouse model (Srsf1NRS). Srsf1NRS/NRS mice displayed small body size, hydrocephaly and male infertility, all associated with ciliary defects. We observed reduced translation of thousands of mRNAs, in particular of ciliary components, in cells derived from this model. Consistently, we found that the lack of cytoplasmic SRSF1 led to decreased abundance of proteins involved in multiciliogenesis and affected ciliary structure and motility in multiciliated cells. Altogether, these results highlight the physiological relevance of the activity of a splicing factor in the cytoplasm.
Project description:Analysis to identify genome-wide differential alternative splicing events in A549 cells in which the levels of the gene SRSF1 were down-regulated with a specific siRNA 9 samples from three independent experiments using A549 cells transfected with lipofectamine alone, scramble siRNA or SRSF1 siRNA
Project description:Purpose: The goals of this study are to determine the role of the serine/ arginine-rich splicing factor 1 (SRSF1) in T cells and autoimmune disease.
Project description:To investigate the cooperative function of FANCD2/SRSF1 complex in the regulation of R-loops, we performed gene expression, isoform and splicing analysis in Hela cells depleted of SRSF1 or expressing SRSF1 mutants and FA-D2 mutant (FA-D2) and wild type (FA-D2+FANCD2) cells.
Project description:Granulosa cells abnormalities are one of the characteristics of premature ovarian insufficiency (POI). Abnormal expression of serine/arginine-rich splicing factor 1 (SRSF1) can causes a variety of diseases, but the role of SRSF1 in mouse granulosa cells has been poorly reported. In this study, we found that SRSF1 was expressed in the nuclei of both mouse oocytes and granulosa cells. Specific knockout of SRSF1 in granulosa cells was performed using Foxl2-creERT2 mice, and morphological staining showed that follicular development was blocked. In addition, granulosa cell proliferation decreased and cell apoptosis increased. The differential gene Gene Ontology (GO) analysis of RNA-Seq results showed abnormal expression of DNA repair, cell killing and other signaling pathways. Alternative splicing (AS) analysis showed that SRSF1 affected DNA damage in granulosa cells by regulating genes related to DNA repair. In conclusion, SRSF1 in granulosa cells affects female reproduction by controlling the development of follicles through regulating granulosa cell DNA repair related genes.
Project description:Alternative splicing generates distinct mRNA variants and is essential for development, homeostasis, and renewal. Proteins of the serine/arginine (SR)-rich splicing factor family are major splicing regulators that are broadly required for organ development as well as cell and organism viability. However, how these proteins support adult organ function remains largely unknown. Here, we used the continuously growing mouse incisor as a model to dissect the functions of the prototypical SR-family protein SRSF1 during tissue homeostasis and renewal. We identified an SRSF1-governed alternative splicing network that is specifically required for dental proliferation and survival of progenitors but dispensable for the viability of differentiated cells. We also observed a similar progenitor-specific role of SRSF1 in the small intestinal epithelium, indicating a conserved function of SRSF1 across adult epithelial tissues. Thus, our findings define a regulatory mechanism by which SRSF1 specifically controls progenitor-specific alternative splicing events to support adult tissue homeostasis and renewal.
Project description:SRSF1, shuttles between the nucleus and cytoplasm affecting post-splicing processes. However, the physiological significance of this remains unclear. Here, we used genome editing to knock-in a nuclear retention signal (NRS) in Srsf1 to create a mouse model harboring a non-shuttling SRSF1 protein. We then assessed whether alblation of shuttling activities of SRSF1 affects its nuclear functions.
Project description:Purpose:Intensive evidence have highlighted the effect of aberrant alternative splicing (AS) events triggered by dysregulation of SR protein family on cancer progression. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods:We conducted comprehensive analysis for the expression and the clinical correlation of SRSF1 in BRCA based on TCGA, Metabric database, clinical tissue samples and BRCA cell lines. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and its binding motif were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. Finally, the expression and their clinical significance were validated in clinical samples and TCGA database. Results:SRSF1 was upregulated in BRCA samples, associated positively with tumor grade and Ki-67 index, and correlated with poor prognosis in hormone receptor positive (HR+) cohort, which facilitated tumor progression in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of PTPMT1. Furthermore, PTPMT1 splice switching regulated by SRSF1 partially mediated the oncogenic role of SRSF1 via the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients. Conclusions:Collectively, SRSF1 exerts the oncogenic roles in BRCA partially through regulating AS of PTPMT1, which could be a candidate prognostic factor and therapeutic target in HR+ BRCA cohort.