Project description:Knockin mice were created that contained a point mutation that elminated the requisite GT in the 5' donor site of each of the NCoRω or NCoRδ splice variants, thus preventing splicing at that site and forcing splicing of the reciprocal splice variant.
Project description:A knockin mouse line created that contains a point mutation that elminates the requisite GT in the 5' donor site of each of the NCoRω splice variants, thus preventing splicing at that site and forcing splicing of the reciprocal NcoRδ splice variant.
Project description:HGPS is a rare premature ageing disease, caused by a mutation in the LMNA gene, which activates a cryptic splice site, resulting in the production of a mutant lamin A isoform, called progerin. Sporadic usage of the same cryptic splice site has been observed with normal physiological aging. As it is unknown how HGPS causes premature ageing defects, we set out to determine the gene signature of both young healthy individuals, old healthy individuals, as well as HGPS patients.
Project description:SNP profiles from 30 pheochromocytomas and paragangliomas were analyzed to detect identical-by-descent haplotypes, highlighting a founder mutation of SDHD in two samples.
Project description:Somatic mutations in the spliceosome have emerged in recent years as oncogenes in human cancer. These mutations are in the factors involved in splice site selection, including a missense mutation (Ser34Phe) in a conserved nucleic acid binding domain of the spicing factor U2AF1. This protein plays a critical role in recognition of the 3'-splice site and assembly of the pre-spliceosomal complex. However, the role that this mutation plays in oncogenesis is still unknown. Here, we have uncovered a non-canonical function of U2AF1. PAR-CLIP and RIP data show that U2AF1 directly binds mature mRNA in the cytoplasm and that binding on or near the start codon results in translational repression. This splicing-independent translational regulatory role of U2AF1 is altered by the S34F mutation, leading to elevated translation of hundreds of mRNA, as revealed by polysome profiling.
Project description:Despite an intensive search for non-coding cancer drivers, only a few have been discovered to date and none have been found among the RNAs contributing to the spliceosome. Here we report a highly recurrent A>C somatic mutation at the third base of U1 spliceosomal RNA in several tumour types. This mutation changes the preferential A-U base-pairing between U1 and 5′ splice site to C-G base-pairing, thereby creating novel splice junctions and altering the splice pattern of multiple genes, including those related to cancer. Clinically, the A>C mutation is associated with alcohol consumption in hepatocellular carcinoma and the aggressive IGHV unmutated subtype of chronic lymphocytic leukaemia (CLL). The U1 hotspot mutation confers an adverse prognosis to CLL patients independently, and may represent a new target for treatment. Our study demonstrates one of the first non-coding drivers in spliceosomal RNAs and reveals a novel mechanism of aberrant splicing in human cancer.
Project description:In the earliest step of spliceosome assembly, the two splice sites flanking an intron are brought into proximity by U1 snRNP and U2AF. The mechanism that facilitates this intron looping is poorly understood. Using a CRISPR interference-based approach to halt RNA polymerase II transcription in the middle of introns, we discovered that the 5 splice site base pairs with a U1 snRNA that is tethered to RNA polymerase II during intron synthesis. Correlation with splicing outcomes demonstrate that these associations are functional. The interactions between 5 splice sites, U1 snRNP, and elongating RNA polymerase II occurs genome-wide. Our findings reveal that during intron synthesis the upstream 5 splice site remains attached to the transcriptional machinery and is thus brought into proximity of the 3 splice site to enable rapid splicing.
Project description:PKD2 Arg803* is the most common mutation in Taiwan ADPKD Cohort. Genotyping of 96 PKD2 Arg803* individuals was performed in Axiom Genome-Wide TWB 2.0 Array Plate to study the existence of founder mutation in Taiwan
Project description:Smyd3 is a histone methyltransferase implicated in tumorigenesis. Here we show that Smyd3 expression in mice is required but not sufficient for chemically induced liver and colon cancer formation. In these organs Smyd3 is functioning in the nucleus as a direct transcriptional activator of several key genes involved in cell proliferation, epithelial-mesenchymal transition, JAK/Stat3 oncogenic pathways, as well as of the c-myc and b-catenin oncogenes. Smyd3 specifically interacts with H3K4Me3-modified histone tails and is recruited to the core promoter regions of many but not all active genes. Smyd3 binding density on target genes positively correlates with increased RNA Pol-II density and transcriptional outputs. The results suggest that Smyd3 is an essential transcriptional potentiator of a multitude of cancer-related genes. Standard Smyd3-deficient (Smyd3-KO) mice were generated using gene-trap ES cell clones (AS0527 from International Gene Trap Consortium), in which a selection cassette, containing the splice acceptor site from mouse EN2 exon 2 followed by the beta-galactosidase and neomycin resistance gene fusion gene and the SV40 polyadenylation sequence was inserted into the 5th intron of the Smyd3 gene. The resulting mice were devoid of Smyd3 mRNA and protein in all tissues, including liver and colon. For the generation of Smyd3-Tg mice the open reading frame of the mouse Smyd3 cDNA, which contained 3 Flag epitopes at the 3â end was inserted into the StuI site of the pTTR1-ExV3 plasmid (Yan et al, 1990). The 6.8 kb HindIII fragment containing the mouse transthyretin enhancer/promoter, intron 1, Smyd3 cDNA, three Flag epitopes and SV40 poly-A site was used to microinject C57Bl/6 fertilized oocytes. Founder animals were identified by Southern blotting and crossed with F1 mice to generate lines. Specific overexpression in the liver was tested by RT-PCR analysis in different tissues.