Sam68 regulation of alternative splicing in the developing cerebellum
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ABSTRACT:
PROVIDER: PRJNA552299 | ENA |
REPOSITORIES: ENA
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Project description:We uncover a Sam68-dependent splicing program during cerebellar development. These events direct proper isoform expression of the genes required to guarantee the establishment of the correct spatial/temporal neural circuitry. The dysregulation in Sam68 null mice leads to functional defects in adult neurons
2020-06-01 | GSE133711 | GEO
Project description:Neuronal alternative splicing is dynamically regulated in a spatiotemporal fashion. We previously found that STAR family proteins (SAM68, SLM1, SLM2) regulate spatiotemporal alternative splicing in the nervous system. However, the whole aspect of alternative splicing programs governed by STARs remains unclear. We deciphered the alternative splicing programs of SAM68 and SLM1 proteins using transcriptomics. We reveal that SAM68 and SLM1 encode distinct alternative splicing programs; SAM68 preferentially controls alternative last exon (ALE) splicing. Interleukin 1-receptor accessory protein (Il1rap) is a novel target for SAM68. The usage of Il1rap ALEs results in mainly two variants encoding two functionally different isoforms, a membrane-bound (mIL1RAcP) and a soluble (sIL1RAcP) type. The brain exclusively expresses mIL1RAcP. SAM68 knockout results in remarkable conversion into sIL1RAcP in the brain, which significantly disturbs IL1RAcP neuronal function. Thus, we uncover the critical role of proper neuronal isoform selection through ALE choice by the SAM68-specific splicing program.
2019-12-29 | GSE110258 | GEO
Project description:The metabolic conversion of oxidative phosphorylation to glycolysis provides tumor cells with energy and biosynthetic substrates, thereby promoting tumorigenesis and malignant progression. However, the mechanisms controlling the tumor metabolic switch is still not entirely clear. Here we demonstrate that SAM68 (gene name: KHDRBS1) as a splicing regulatory factor is frequently overexpressed in Lung adenocarcinoma (LUAD) and negatively correlated with the prognosis of LUAD patients. we find SAM68 promotes LUAD cells tumorigenesis and metastasis both in vitro and in vivo by regulating cancer metabolic switch. SAM68 drives cancer metabolism by mediating alternative splicing of Pyruvate kinase (PKM) pre-mRNAs, finally promoting the formation of PKM2. Mechanically, Sam68 interacted with the splicing repressor hnRNP A1, and depletion of hnRNP A1 or mutations that impair this interaction attenuated the PKM splicing regulation. Together, our work demonstrates key roles of SAM68 in the cancer metabolic conversion by regulating alternative splicing and SAM68 may be a promising therapeutic target for treating LUAD.This project looks into how SAM68 levels affect cancer cell phenotype in vitro
2020-11-04 | GSE149120 | GEO
Project description:Sam68 is a member of the STAR family of proteins that directly link signal transduction with post-transcriptional gene regulation. Sam68 controls the alternative splicing of many oncogenic proteins and its role is modulated by post-translational modifications, including serine/threonine phosphorylation, that differ at various stages of the cell cycle. However, the molecular basis and mechanisms of these modulations remain largely unknown. Here, we combined mass spectrometry, NMR spectroscopy, and cell biology techniques to provide a comprehensive post-translational modification (PTM) mapping of Sam68 at different stages of the cell cycle in HEK293 and HCT116 cells. We established that Sam68 is specifically phosphorylated at T33 and T317 by Cdk1, and demonstrated that these phosphorylation events reduce the binding of Sam68 to RNA, control its cellular localization, and reduce its alternative splicing activity, leading to a reduction in the induction of apoptosis and an increase in the proliferation of HCT116 cells.
2023-03-11 | PXD032716 | Pride
Project description:SAM68 is an RNA binding protein frequently up-regulated in several human cancers and its oncogenic activity has often been associated with its splicing activity. Nevertheless, the genome-wide impact of SAM68 on the transcriptome of cancer cells is still unknown. Herein, by high-throughput RNA sequencing analysis of MDA-MB-231 SAM68-silenced cells, we uncover an extensive modulation of triple-negative breast cancer cell transcriptome by this splicing factor.
2022-04-04 | GSE140754 | GEO
Project description:Male germ cells express the widest repertoire of transcript variants in mammalian tissues. Nevertheless, factors and mechanisms underlying such pronounced diversity are largely unknown. The splicing regulator Sam68 is highly expressed in meiotic cells and its ablation results in defective spermatogenesis. Herein, we uncover an extensive splicing program operated by Sam68 across meiosis, primarily characterized by alternative last exon (ALE) regulation in genes of functional relevance for spermatogenesis. Lack of Sam68 preferentially causes premature transcript termination at internal polyadenylation sites.
2019-03-12 | GSE122929 | GEO
Project description:SAM68 promotes Lung adenocarcinoma tumorigenesis by regulating cancer metabolic conversion through alternative splicing
| PRJNA627415 | ENA
Project description:Alternative pre-mRNA splicing critically contributes to the generation of protein variety in a tissue- and development-specific manner. Alterations in the normal pathways of alternative splicing (AS) have been associated with the growth and maintenance of several tumour types, and have been indicated as candidate bio-markers of tumour progression, metastasis and patient survival. In this study we applied genome-wide exon array technology to investigate AS events that may distinguish between human medulloblastoma and normal cerebellum. We initially investigated gene-level expression profiles to identify samples expressing gene signatures characteristic of previously described MB molecular subgroups. 3 medulloblastomas significantly over-expressed genes typically belonging to the Shh signalling pathway or associated with a granule cell progenitor status and were therefore classified as Shh-activated tumours (MB1). The remaining tumour samples were grouped together as medulloblastoma subset 2 (MB2). We then applied the Splicing Index algorithm and identified 1260 unique genes containing at least one candidate exon whose inclusion rate differed between different sample subgroups. Following the analysis of candidate event expression plots and gene structure annotation, we selected 14 examples of differential splicing of cassette exons and successfully validated 11 of them by semi-quantitative RT-PCR in a selection of the initial sample-set and subsequently in an independent set of 10 normal cerebellum and 20 medulloblastoma samples. Through the analysis of AS pathway in in vitro cultures of cerebellar granule cell progenitors (the putative cell of origin of least a subset of medulloblastomas), we showed that medulloblastoma-associated AS patterns could be indicative of a normal cerebellar undifferentiated phenotype and suggested that activation of oncogenic pathways during the development of the cerebellum may lead to a failure of neuronal differentiation also through the disruption of AS programs.
2011-01-01 | E-MTAB-292 | biostudies-arrayexpress
Project description:Our previous studies of proteomic-coupled-network analysis of AR protein interaction complexes (Paliouras et al., Integrative Biology, 2011) identified a number of proteins involved in RNA metabolism, specifically alternative RNA splicing. We selected two interacting RNA splicing proteins, SAM68 and DDX5 to examine RNA splicing events in prostate cancer (PCa). This analysis suggests a much more robust effect on RNA splicing with AR dictating either an exon-inclusion or -exclusion pathway. To establish the true physiological roles of AR in alternative RNA splicing, we opted to further examine the changes in global splicing profiles of LNCaP PCa cells, stimulated with and without androgens in conjunction with overexpression studies of SAM68 and DDX5.
2021-06-04 | GSE176124 | GEO
Project description:Mammalian development is an intricate process regulated by multiple gene isoforms and their epigenetic states, which are yet undefined. Using integrative massive parallel sequencing and bioinformatics approach, we built genome-wide inventory of transcript variants, their promoters and histone modification states during normal development, using mouse cerebellum as model system. The data we integrated consists of 29,589 (4,792 novel) promoters that transcribe 61,525 (12,796 novel) distinct mRNAs, corresponding to 14,508 protein-coding and 9,862 non-coding genes. While 68% of the multi-transcript genes exhibit alternative splicing, 78% use alternative transcriptional events that are regulated during cerebellar development through H3K4me3 and H3K27me3. The data presented highlight the magnitude of alternative promoters and transcriptional termination as major source of transcriptome diversity along with alternative splicing. We also show that alternative promoters differentially activated during normal cerebellar development are aberrantly used in medulloblastoma, emphasizing the importance of studying gene regulation and function at the isoform-level. Study of transcriptome diversity in cerebellar development. We performed mRNA-seq and ChIP-seq experiments. mRNA-seq were performed on total RNA isolated from two P0, P5, P15 and adult cerebellum using 10 microgram of total RNA as the starting material for sequencing library prep. For each stage, mRNA-seq data was obtained from two lanes of a flowcell. For ChIP-seq experiments, solubilized chromatin was prepared by pooling multiple cerebellum tissues (3-18) and then ChIP-enriched DNA (using anti-RNAP II, anti-H3K4me3, anti-H3K27me3, or negative control IgG antibodies) were isolated. 10 microgram of ChIP-enriched DNA was used to prepare the ChIP-seq library for sequencing in a single lane.
2011-06-07 | E-GEOD-23525 | biostudies-arrayexpress