Project description:Melanoma patients with high mRNA levels of the HDL receptor SR-BI (SCARB1) reveal poor survival outcome. The aim of the study was to evaluate the role of SR-BI in cancer progression. Therefore, SR-BI was targeted either by siRNA or by using the SR-BI specific lipid transfer inhibitor BLT-1. The SR-BI knockdown specifically revealed reduced protein glycosylation, STAT5 target gene expression and EMT pathway activation. Thus, SR-BI target genes reflect the metastatic phenotype in melanoma cells. We used the transcriptome analysis to compare SR-BI depletion to BLT-1 treatment (which specifically blocks SR-BI mediated lipid transfer) in human melanoma cells.
Project description:SR proteins are well-characterized RNA binding proteins that promote exon inclusion by binding to exonic splicing enhancers (ESEs). However, it has been unclear whether regulatory rules deduced on model genes apply generally to activities of SR proteins in the cell. Here, we report global analyses of two prototypical SR proteins SRSF1 (SF2/ASF) and SRSF2 (SC35) using splicing-sensitive arrays and CLIP-seq on mouse embryo fibroblasts (MEFs). Unexpectedly, we find that these SR proteins promote both inclusion and skipping of exons in vivo, but their binding patterns do not explain such opposite responses. Further analyses reveal that loss of one SR protein is accompanied by coordinated loss or compensatory gain in the interaction of other SR proteins at the affected exons. Therefore, specific effects on regulated splicing by one SR protein actually depend on a complex set of relationships with multiple other SR proteins in mammalian genomes.
Project description:SR proteins are well-characterized RNA binding proteins that promote exon inclusion by binding to exonic splicing enhancers (ESEs). However, it has been unclear whether regulatory rules deduced on model genes apply generally to activities of SR proteins in the cell. Here, we report global analyses of two prototypical SR proteins SRSF1 (SF2/ASF) and SRSF2 (SC35) using splicing-sensitive arrays and CLIP-seq on mouse embryo fibroblasts (MEFs). Unexpectedly, we find that these SR proteins promote both inclusion and skipping of exons in vivo, but their binding patterns do not explain such opposite responses. Further analyses reveal that loss of one SR protein is accompanied by coordinated loss or compensatory gain in the interaction of other SR proteins at the affected exons. Therefore, specific effects on regulated splicing by one SR protein actually depend on a complex set of relationships with multiple other SR proteins in mammalian genomes. SRSF1 and SRSF2 CLIP-seq
Project description:The high-density lipoprotein receptor SR-B1 mediates cellular uptake of several lipid species, including cholesterol and vitamin E. During early development, SR-B1 is located in the maternal-fetal interface, where it facilitates vitamin E transport towards the embryo. Consequently, embryos lacking SR-B1 are vitamin E-deficient, and around half of them fail to close the neural tube and show neural tube defects (NTD). Here, we studied the transcriptomic profile of mouse embryos lacking SR-B1 to identify the molecular determinants of this phenotypic difference. We used RNA-Seq to analyze the expression of mRNA globally in E9.5 wild-type embryos and embryos lacking SR-B1 with or without NTD, in order to compare expression profiles in those groups and to identify putative genes driving phenotypic differences.
Project description:We used GFP-tagged SR proteins expressed at endogenous levels and iCLIP to identify and compare endogenous RNA targets of individual SR proteins, map the preferential sites of binding, compare binding pattern and binding motifs between family members and to NXF1 and quantify binding of SR proteins and NXF1 to spliced versus unspliced RNAs to study the role of SR proteins in mRNA export via NXF1.
Project description:Classical NF-κB activity can be inhibited by overexpression of the IκBα super repressor (SR). To determine the role of NF-κB in rhabdomyosarcoma cells, we overexpressed the IκBα SR in RH30 rhabdomyosarcoma cells. IκBα SR was overexpressed in RH30 cells. RH30 vector cells were used as control group.