Project description:We sequenced mRNA from E18.5 mouse cortex (3 wild-type vs 3 Nova2-/- and 3 wild-type vs 3 Nova1-/-) and from E18.5 mouse mid- and hind-brain (3 wild-type vs 3 Nova1-/-) to compare gene expression level and alternative splicing events between wild-type and Nova mutant mice.
Project description:To gain insight into the potential molecular mechanisms by which PGRN regulates influenza viral replication, proteomic analyses of whole mouse lung tissue from wild-type (WT) versus (vs) PGRN knockout (KO) mice were performed to identify proteins regulated by the absence vs presence of PGRN.
Project description:Scaffold Attachment Factor B (SAFB) is a conserved RNA Binding Protein (RBP) that is essential for early mammalian development. However, the RNAs that associate with SAFB in mouse embryonic stem cells have not been characterized. Here, we addressed this unknown using RNA-seq and SAFB RNA immunoprecipitation followed by RNA-seq (RIP-seq) in wild-type mouse embryonic stem cells (ESCs) and in ESCs in which SAFB and SAFB2 were knocked out. The transcript most enriched in SAFB association was the lncRNA Malat1, which contains a series of purine-rich motifs in its 5 end. Beyond Malat1, SAFB predominantly associated with introns of protein-coding genes also through purine-rich motifs. Knockout of SAFB/2 led to down- and upregulation of genes in multiple biological pathways. The nascent transcripts of many downregulated genes associated with high levels of SAFB in wild-type cells, implying that SAFB binding promotes the expression of these genes. Reintroduction of SAFB into double-knockout cells restored gene expression towards wild-type levels, an effect that was again observable at the level of nascent transcripts. Proteomic analyses indicate an enrichment of nuclear speckle-associated, SR proteins in FLAG-tagged SAFB immunoprecipitated samples. Comparison to immunoprecipitates made from FLAG-tagging of another nuclear-enriched RNA-binding protein called HNRNPU (also known as SAF-A) identified both similarities and differences. Perhaps most notably, we observed a stronger enrichment for speckle-associated proteins in SAFB immunoprecipitations and a strong enrichment for paraspeckle-associated proteins in HNRNPU immunoprecipitations. Our findings suggest that among other potential functions in mouse embryonic stem cells, SAFB directly promotes the expression of a subset of genes through its ability to bind purine regions in nascent RNA.
Project description:Epithelial cells and differentiated fiber cells represent distinct compartments in the ocular lens. While previous studies have revealed proteins that are preferentially expressed in epithelial vs. fiber cells, a comprehensive proteomics library comparing the molecular composition of epithelial vs. fiber cells is essential for understanding lens formation, function, disease and regenerative potential, and for efficient differentiation of pluripotent stem cells for modeling of lens development and pathology in vitro. To compare protein composition between the lens epithelium and fibers, we employed tandem mass spectrometry (2DLC/ MS) analysis of micro-dissected mouse P0.5 lenses. Functional classifications of the top 525 identified proteins into gene ontology categories by molecular process and subcellular localization, were adapted for lens. Expression levels of both epithelial and fiber proteomes were compared with their temporal and spatial mRNA levels using E14.5, E16.5, E18.5, and P0.5 RNA-Seq data sets. During this developmental time window, multiple complex biosynthetic and catabolic processes generate the molecular and structural foundation for lens transparency. As expected, crystallins showed a high correlation between their mRNA and protein levels. Comprehensive data analysis confirmed and/or predicted roles for transcription factors (TFs), RNA-binding proteins, translational apparatus including ribosomal heterogeneity and initiation factors, microtubules, cytoskeletal and membrane proteins in lens formation and maturation. Our data highlighted many proteins with unknown function in the lens that were preferentially enriched in epithelium or fibers, setting the stage for future studies to further dissect the roles of these proteins in fiber cell differentiation vs. epithelial cell maintenance. In conclusion, the present proteomic datasets established reference mouse lens epithelium and fiber cell proteomes, provided quantitative analyses of protein and RNA-Seq data, and probed the major proteome remodeling required to form the mature lens fiber cells.