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: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: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: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.
2015-05-30 | GSE69391 | GEO
Project description:A CIB1 Splice-site Founder Mutation in Families with Typical Epidermodysplasia Verruciformis
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: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.
