Poster abstracts
Poster number 9 submitted by Caleb Embree
Investigating the role of EFTUD2 in pre-mRNA splicing and EJC deposition
Caleb M. Embree (Department of Molecular Genetics, Center for RNA Biology), Guramrit Singh (Department of Molecular Genetics, Center for RNA Biology)
Abstract:
During the gene expression pathway, pre-mRNA splicing is one of the earliest and most important RNA processing steps, which occurs co-transcriptionally. The end result of pre-mRNA splicing is an mRNP particle comprised of mRNA and RNA binding proteins deposited during splicing. One complex of RNA binding proteins, the exon junction complex (EJC), plays important roles in steps ranging from pre-mRNA splicing in the nucleus to mRNA degradation in the cytoplasm. Though the EJC is deposited by the spliceosome, the responsible spliceosomal proteins and their precise function in EJC deposition is not fully known. EFTUD2, a splicing regulator and member of the U5 snRNP that sits adjacent to the EJC within the activated spliceosome, may have a role in EJC deposition. Mutations in EFTUD2 and the EJC core factor EIF4A3 cause similar cranio-facial disorders, hinting that they function in a similar pathway. Using clinically relevant C-terminally truncated EFTUD2 proteins we are investigating the relationship between EFTUD2 and the EJC. Our work shows that the C-terminal truncations of EFTUD2 destabilize the protein, which suggests that these mutations likely cause EFTUD2 haploinsufficiency in patients. Our hypothesis is that such a haploinsufficiency leads to defects in spliceosome and/or EJC assembly resulting in splicing errors. Using EFTUD2 haploinsufficient (or knockdown) HEK293 cells, we plan to identify the splicing errors via RNA-Seq and assess transcriptome-wide spliceosome assembly via spliceosome profiling. Together these data will allow us to determine how reduced levels of EFTUD2 impairs spliceosome and/or EJC assembly leading to splicing defects.
Keywords: Exon Junction Complex, Splicing, developmental disorders